Kolb-List Digest Archive

Wed 05/09/18


Total Messages Posted: 15



Today's Message Index:
----------------------
 
     1. 09:41 AM - Re: Re: High Thrust Line Question (George Helton)
     2. 11:17 AM - Re: Re: High Thrust Line Question (John Hauck)
     3. 11:19 AM - Re: Re: High Thrust Line Question (Bill Berle)
     4. 11:38 AM - Re: Re: High Thrust Line Question (George Helton)
     5. 12:56 PM - Re: Re: High Thrust Line Question (Bill Berle)
     6. 01:32 PM - Re: Re: High Thrust Line Question (Jack Hart)
     7. 01:35 PM - Re: Re: High Thrust Line Question (Jack Hart)
     8. 01:41 PM - Re: Re: High Thrust Line Question (Jack Hart)
     9. 01:57 PM - Re: Re: High Thrust Line Question (Jack Hart)
    10. 02:10 PM - Re: Re: High Thrust Line Question (George Helton)
    11. 02:28 PM - Re: Re: High Thrust Line Question (Jack Hart)
    12. 03:29 PM - Re: Re: High Thrust Line Question (Jack Hart)
    13. 04:21 PM - Re: Re: High Thrust Line Question (John Hauck)
    14. 05:00 PM - Re: Re: High Thrust Line Question (Jack Hart)
    15. 05:31 PM - Re: Re: High Thrust Line Question (George Helton)
 
 
 


Message 1


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    Time: 09:41:10 AM PST US
    From: George Helton <gdhelton@gmail.com>
    Subject: Re: High Thrust Line Question
    Well Bill, thanks for bringing up the topic. I replaced my little Rotax 377 with new low rpm Hirth 2702 over the winter. I really hadnt measured the distance between the prop hub and boom tube. You sparked my interest so I stopped by my hanger this morning to check it out. The Hirth uses a G50 gearbox with 2:29 to 1 ratio. which translates to 2400 rpm prop speed @ the engines max. HP rpm of 5500rpm. Anyway, it measures 35.5 inches. This is on a Kolb original Firestar. I did have to move the engine forward 2.625 to compensate for the extra weight of the new gear box. I went with a 64 3 blade Powerfin prop set at 6.4 degrees of pitch. This setup gives me 3.5 of clearance from the boom tube. Thanks for inspiring me to check it out. Im sure there is a good combination of prop out there for an HKS. George Helton 1986 Firestar, FS100 14GDH Mesick, Michigan gdhelton@gmail.com Sent from my iPhone > On May 8, 2018, at 11:08 PM, Bill Berle <victorbravo@sbcglobal.net> wrote: > > > Everybody THANK YOU for taking time for this discussion. > > I spoke to the Kolb factory today by phone, and went out to the local UL flying field to see an HKS engine run. > > Duane and Bryan at Kolb were asked one specific question by me: What is the maximum number of inches allowable or advisable between the center of the propeller and the top of the tailboom? > > Bryan said that 36 inches is about standard for a "normal" Firestar, and he would not want to fly an airplane with that distance raised to 39 or 40 inches. > > I went back to my hangar and measured, and the distance on my Firestar would be over 40 or 41 inches if I turned the gearbox upward. So if the Kolb factory owner says 40 inches is too high, I can only be humble and assume that I wouldn't want to fly it at 40 inches either. If any of the highly experienced Kolbers on this forum are flying with their thrust line 40 inches above the tailboom, I REALLY would like to know about it pronto. > > As big of an ego as I have had a few times in my life, and as much as I think of myself as a reasonably skilled pilot, I don't need to be a test pilot here and try to push any envelope at this early stage. So if I can ask the Kolb ilst a favor... if any of you are flying a Firestar with the engine thrust line 39 or 40 or 41 incvhes above the tailboom please post this on the list and let me know ifyou have any issues with the handling, pitch-over, etc. > > Bill Berle > www.ezflaphandle.com - safety & performance upgrade for light aircraft > www.grantstar.net - winning proposals for non-profit and for-profit entities > > -------------------------------------------- > On Tue, 5/8/18, Richard Pike <thegreybaron@charter.net> wrote: > > Subject: Kolb-List: Re: High Thrust Line Question > To: kolb-list@matronics.com > Date: Tuesday, May 8, 2018, 4:38 PM > > Pike" <thegreybaron@charter.net> > > Bill; notice the extent to which Rick > raised his engine. (Great pictures) Maybe you can leave the > gearbox down and raise the engine up? > > -------- > Richard Pike > Kolb MKIII N420P (420ldPoops) > Kingsport, TN 3TN0 > > Forgiving is tough, being forgiven is > wonderful, and God's grace really is amazing. > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=479963#479963 > > > > > > > The Kolb-List Email Forum - > Navigator to browse > List Un/Subscription, > 7-Day Browse, Chat, FAQ, > - MATRONICS WEB FORUMS - > via the Web Forums! > - NEW MATRONICS LIST WIKI - > Email List Wiki! > - List Contribution Web Site - > support! > > -Matt Dralle, List Admin. > > > > > > > >


    Message 2


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    Time: 11:17:49 AM PST US
    From: "John Hauck" <jhauck@elmore.rr.com>
    Subject: Re: High Thrust Line Question
    3.5" is about 2.5" to much. 1" clearance operating with stand Lord Mounts is more than adequate clearance. I flew with a 72" prop and .75" clearance for many hours, including my last 48 day flight to Alaska and back. Prop might be noisier with the tips passing that close to the tail boom, but I'll take the lower thrust line over noise. I'm flying with a 68" prop that gives me 2.75" of clearance. Can't tell the difference in noise level. It is still noisy. john h mkIII Titus, Alabama -----Original Message----- From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] On Behalf Of George Helton Sent: Wednesday, May 09, 2018 11:40 AM Subject: Re: Kolb-List: Re: High Thrust Line Question Well Bill, thanks for bringing up the topic. I replaced my little Rotax 377 with new low rpm Hirth 2702 over the winter. I really hadnt measured the distance between the prop hub and boom tube. You sparked my interest so I stopped by my hanger this morning to check it out. The Hirth uses a G50 gearbox with 2:29 to 1 ratio. which translates to 2400 rpm prop speed @ the engines max. HP rpm of 5500rpm. Anyway, it measures 35.5 inches. This is on a Kolb original Firestar. I did have to move the engine forward 2.625 to compensate for the extra weight of the new gear box. I went with a 64 3 blade Powerfin prop set at 6.4 degrees of pitch. This setup gives me 3.5 of clearance from the boom tube. Thanks for inspiring me to check it out. Im sure there is a good combination of prop out there for an HKS. George Helton 1986 Firestar, FS100 14GDH Mesick, Michigan gdhelton@gmail.com Sent from my iPhone > On May 8, 2018, at 11:08 PM, Bill Berle <victorbravo@sbcglobal.net> wrote: > > > Everybody THANK YOU for taking time for this discussion. > > I spoke to the Kolb factory today by phone, and went out to the local UL flying field to see an HKS engine run. > > Duane and Bryan at Kolb were asked one specific question by me: What is the maximum number of inches allowable or advisable between the center of the propeller and the top of the tailboom? > > Bryan said that 36 inches is about standard for a "normal" Firestar, and he would not want to fly an airplane with that distance raised to 39 or 40 inches. > > I went back to my hangar and measured, and the distance on my Firestar would be over 40 or 41 inches if I turned the gearbox upward. So if the Kolb factory owner says 40 inches is too high, I can only be humble and assume that I wouldn't want to fly it at 40 inches either. If any of the highly experienced Kolbers on this forum are flying with their thrust line 40 inches above the tailboom, I REALLY would like to know about it pronto. > > As big of an ego as I have had a few times in my life, and as much as I think of myself as a reasonably skilled pilot, I don't need to be a test pilot here and try to push any envelope at this early stage. So if I can ask the Kolb ilst a favor... if any of you are flying a Firestar with the engine thrust line 39 or 40 or 41 incvhes above the tailboom please post this on the list and let me know ifyou have any issues with the handling, pitch-over, etc. > > Bill Berle > www.ezflaphandle.com - safety & performance upgrade for light aircraft > www.grantstar.net - winning proposals for non-profit and for-profit entities > > -------------------------------------------- > On Tue, 5/8/18, Richard Pike <thegreybaron@charter.net> wrote: > > Subject: Kolb-List: Re: High Thrust Line Question > To: kolb-list@matronics.com > Date: Tuesday, May 8, 2018, 4:38 PM > > Pike" <thegreybaron@charter.net> > > Bill; notice the extent to which Rick > raised his engine. (Great pictures) Maybe you can leave the > gearbox down and raise the engine up? > > -------- > Richard Pike > Kolb MKIII N420P (420ldPoops) > Kingsport, TN 3TN0 > > Forgiving is tough, being forgiven is > wonderful, and God's grace really is amazing. > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=479963#479963 > > > > > > > The Kolb-List Email Forum - > Navigator to browse > List Un/Subscription, > 7-Day Browse, Chat, FAQ, > - MATRONICS WEB FORUMS - > via the Web Forums! > - NEW MATRONICS LIST WIKI - > Email List Wiki! > - List Contribution Web Site - > support! > > -Matt Dralle, List Admin. > > > > > > > >


    Message 3


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    Time: 11:19:39 AM PST US
    From: Bill Berle <victorbravo@sbcglobal.net>
    Subject: Re: High Thrust Line Question
    I have been pulling out what's left of my hair over this issue. I really don't want to quit, I LIKE the Kolb airframe and it will fit my mission well. I like the HKS fuel economy and improved reliability. I just wound up with the wrong gearbox on it and cannot afford to change it. What I have learned thus far is: 1) My 3.47 to 1 gearbox really wants to swing a larger propeller than what is actually "correct" for the height of the thrust line on the Kolb airframe. 2) Turning the gearbox upwards will solve the prop diameter problem, but it creates a thrust line that is higher than the Kolb factory thinks is advisable. 3) I could easily go to a 4 or 5 blade propeller, solves the gearbox AND thrust line problems, but that interferes with folding the wings. I have considered many possible solutions or "work-arounds" : 1) Get a 5 blade propeller and remove it after every flight, which would allow ALL of the problems to be solved, at the cost of additional time and effort every time I fly. This will cost the least of all the "solutions". 2) Remove the wings after every flight instead of folding the wings. This allows a 5 blade propeller to be used but adds complexity and requires me to build a complicated ground fixture to allow the wings to be removed and installed by myself alone. 3) Make a folding propeller, like the electric R/C model gliders have, where the blades fold rearward. This solves all of the problems, no complex ground equipment, but designing and manufacturing such a propeller will be prohibitvely expensive. 4) Buy another gearbox from HKS. This is the best solution mechanically, but I cannot afford it. 5) Turn the gearbox upwards, install the right propeller, and live with the possibly dangerous or funky flight handling of the airplane. Any other/better/wiser/workable ideas from the Kolb List are very very welcome! Bill Berle www.ezflaphandle.com - safety & performance upgrade for light aircraft www.grantstar.net - winning proposals for non-profit and for-profit entities -------------------------------------------- On Wed, 5/9/18, George Helton <gdhelton@gmail.com> wrote: Subject: Re: Kolb-List: Re: High Thrust Line Question To: kolb-list@matronics.com Date: Wednesday, May 9, 2018, 9:39 AM Helton <gdhelton@gmail.com> Well Bill, thanks for bringing up the topic. I replaced my little Rotax 377 with new low rpm Hirth 2702 over the winter. I really hadnt measured the distance between the prop hub and boom tube. You sparked my interest so I stopped by my hanger this morning to check it out. The Hirth uses a G50 gearbox with 2:29 to 1 ratio. which translates to 2400 rpm prop speed @ the engines max. HP rpm of 5500rpm. Anyway, it measures 35.5 inches. This is on a Kolb original Firestar. I did have to move the engine forward 2.625 to compensate for the extra weight of the new gear box. I went with a 64 3 blade Powerfin prop set at 6.4 degrees of pitch. This setup gives me 3.5 of clearance from the boom tube. Thanks for inspiring me to check it out. Im sure there is a good combination of prop out there for an HKS. George Helton 1986 Firestar, FS100 14GDH Mesick, Michigan gdhelton@gmail.com Sent from my iPhone > On May 8, 2018, at 11:08 PM, Bill Berle <victorbravo@sbcglobal.net> wrote: > > --> Kolb-List message posted by: Bill Berle <victorbravo@sbcglobal.net> > > Everybody THANK YOU for taking time for this discussion. > > I spoke to the Kolb factory today by phone, and went out to the local UL flying field to see an HKS engine run. > > Duane and Bryan at Kolb were asked one specific question by me: What is the maximum number of inches allowable or advisable between the center of the propeller and the top of the tailboom? > > Bryan said that 36 inches is about standard for a "normal" Firestar, and he would not want to fly an airplane with that distance raised to 39 or 40 inches. > > I went back to my hangar and measured, and the distance on my Firestar would be over 40 or 41 inches if I turned the gearbox upward. So if the Kolb factory owner says 40 inches is too high, I can only be humble and assume that I wouldn't want to fly it at 40 inches either. If any of the highly experienced Kolbers on this forum are flying with their thrust line 40 inches above the tailboom, I REALLY would like to know about it pronto. > > As big of an ego as I have had a few times in my life, and as much as I think of myself as a reasonably skilled pilot, I don't need to be a test pilot here and try to push any envelope at this early stage. So if I can ask the Kolb ilst a favor... if any of you are flying a Firestar with the engine thrust line 39 or 40 or 41 incvhes above the tailboom please post this on the list and let me know ifyou have any issues with the handling, pitch-over, etc. > > Bill Berle > www.ezflaphandle.com - safety & performance upgrade for light aircraft > www.grantstar.net - winning proposals for non-profit and for-profit entities > > -------------------------------------------- > On Tue, 5/8/18, Richard Pike <thegreybaron@charter.net> wrote: > > Subject: Kolb-List: Re: High Thrust Line Question > To: kolb-list@matronics.com > Date: Tuesday, May 8, 2018, 4:38 PM > > --> Kolb-List message posted by: "Richard > Pike" <thegreybaron@charter.net> > > Bill; notice the extent to which Rick > raised his engine. (Great pictures) Maybe you can leave the > gearbox down and raise the engine up? > > -------- > Richard Pike > Kolb MKIII N420P (420ldPoops) > Kingsport, TN 3TN0 > > Forgiving is tough, being forgiven is > wonderful, and God's grace really is amazing. > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=479963#479963 > > > > > > > The Kolb-List Email Forum - > Navigator to browse > List Un/Subscription, > 7-Day Browse, Chat, FAQ, > - MATRONICS WEB FORUMS - > via the Web Forums! > - NEW MATRONICS LIST WIKI - > Email List Wiki! > - List Contribution Web Site - > support! > > -Matt Dralle, List Admin. > > > > > > > > The Kolb-List Email Forum - Navigator to browse List Un/Subscription, 7-Day Browse, Chat, FAQ, - MATRONICS WEB FORUMS - via the Web Forums! - NEW MATRONICS LIST WIKI - Email List Wiki! - List Contribution Web Site - support! -Matt Dralle, List Admin.


    Message 4


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    Time: 11:38:47 AM PST US
    From: George Helton <gdhelton@gmail.com>
    Subject: Re: High Thrust Line Question
    Bill, I know that this might sound crazy but, cant you just buy a different set of gears for the gearbox? Being a mechanic may be a benefit here but I cant imagine that HKS cant supply replacement parts. The gearbox case doesnt care what gears fit inside of it. If they dont, Id sure shy away from buying one. George Helton 1986 Firestar, FS100 14GDH Mesick, Michigan gdhelton@gmail.com Sent from my iPhone > On May 9, 2018, at 2:18 PM, Bill Berle <victorbravo@sbcglobal.net> wrote: > > > I have been pulling out what's left of my hair over this issue. I really don't want to quit, I LIKE the Kolb airframe and it will fit my mission well. I like the HKS fuel economy and improved reliability. I just wound up with the wrong gearbox on it and cannot afford to change it. > > What I have learned thus far is: > > 1) My 3.47 to 1 gearbox really wants to swing a larger propeller than what is actually "correct" for the height of the thrust line on the Kolb airframe. > > 2) Turning the gearbox upwards will solve the prop diameter problem, but it creates a thrust line that is higher than the Kolb factory thinks is advisable. > > 3) I could easily go to a 4 or 5 blade propeller, solves the gearbox AND thrust line problems, but that interferes with folding the wings. > > I have considered many possible solutions or "work-arounds" : > > 1) Get a 5 blade propeller and remove it after every flight, which would allow ALL of the problems to be solved, at the cost of additional time and effort every time I fly. This will cost the least of all the "solutions". > > 2) Remove the wings after every flight instead of folding the wings. This allows a 5 blade propeller to be used but adds complexity and requires me to build a complicated ground fixture to allow the wings to be removed and installed by myself alone. > > 3) Make a folding propeller, like the electric R/C model gliders have, where the blades fold rearward. This solves all of the problems, no complex ground equipment, but designing and manufacturing such a propeller will be prohibitvely expensive. > > 4) Buy another gearbox from HKS. This is the best solution mechanically, but I cannot afford it. > > 5) Turn the gearbox upwards, install the right propeller, and live with the possibly dangerous or funky flight handling of the airplane. > > Any other/better/wiser/workable ideas from the Kolb List are very very welcome! > > > > > Bill Berle > www.ezflaphandle.com - safety & performance upgrade for light aircraft > www.grantstar.net - winning proposals for non-profit and for-profit entities > > -------------------------------------------- > On Wed, 5/9/18, George Helton <gdhelton@gmail.com> wrote: > > Subject: Re: Kolb-List: Re: High Thrust Line Question > To: kolb-list@matronics.com > Date: Wednesday, May 9, 2018, 9:39 AM > > Helton <gdhelton@gmail.com> > > Well Bill, thanks for bringing up the > topic. I replaced my little Rotax 377 with new low rpm Hirth > 2702 over the winter. I really hadnt measured the > distance between the prop hub and boom tube. You sparked my > interest so I stopped by my hanger this morning to check it > out. The Hirth uses a G50 gearbox with 2:29 to 1 ratio. > which translates to 2400 rpm prop speed @ the engines > max. HP rpm of 5500rpm. > Anyway, it measures 35.5 inches. This > is on a Kolb original Firestar. I did have to move the > engine forward 2.625 to compensate for the extra weight > of the new gear box. I went with a 64 3 blade Powerfin > prop set at 6.4 degrees of pitch. This setup gives me 3.5 > of clearance from the boom tube. Thanks for inspiring me to > check it out. Im sure there is a good combination > of prop out there for an HKS. > George Helton > 1986 Firestar, FS100 > 14GDH > Mesick, Michigan > gdhelton@gmail.com > > Sent from my iPhone > >> On May 8, 2018, at 11:08 PM, Bill > Berle <victorbravo@sbcglobal.net> > wrote: >> >> --> Kolb-List message posted > by: Bill Berle <victorbravo@sbcglobal.net> >> >> Everybody THANK YOU for taking > time for this discussion. >> >> I spoke to the Kolb factory today > by phone, and went out to the local UL flying field to see > an HKS engine run. >> >> Duane and Bryan at Kolb were asked > one specific question by me: What is the maximum > number of inches allowable or advisable between the center > of the propeller and the top of the tailboom? >> >> Bryan said that 36 inches is about > standard for a "normal" Firestar, and he would not want to > fly an airplane with that distance raised to 39 or 40 > inches. >> >> I went back to my hangar and > measured, and the distance on my Firestar would be over 40 > or 41 inches if I turned the gearbox upward. So if the Kolb > factory owner says 40 inches is too high, I can only be > humble and assume that I wouldn't want to fly it at 40 > inches either. If any of the highly experienced Kolbers on > this forum are flying with their thrust line 40 inches above > the tailboom, I REALLY would like to know about it pronto. >> >> As big of an ego as I have had a > few times in my life, and as much as I think of myself as a > reasonably skilled pilot, I don't need to be a test > pilot here and try to push any envelope at this early stage. > So if I can ask the Kolb ilst a favor... if any of you are > flying a Firestar with the engine thrust line 39 or 40 or 41 > incvhes above the tailboom please post this on the list and > let me know ifyou have any issues with the handling, > pitch-over, etc. >> >> Bill Berle >> www.ezflaphandle.com - > safety & performance upgrade for light aircraft >> www.grantstar.net > - winning proposals for non-profit and > for-profit entities >> >> > -------------------------------------------- >> On Tue, 5/8/18, Richard Pike > <thegreybaron@charter.net> > wrote: >> >> Subject: Kolb-List: Re: High > Thrust Line Question >> To: kolb-list@matronics.com >> Date: Tuesday, May 8, 2018, 4:38 > PM >> >> --> Kolb-List message posted > by: "Richard >> Pike" <thegreybaron@charter.net> >> >> Bill; notice the extent to which > Rick >> raised his engine. (Great > pictures) Maybe you can leave the >> gearbox down and raise the engine > up? >> >> -------- >> Richard Pike >> Kolb MKIII N420P (420ldPoops) >> Kingsport, TN 3TN0 >> >> Forgiving is tough, being forgiven > is >> wonderful, and God's grace really > is amazing. >> >> >> >> >> Read this topic online here: >> >> http://forums.matronics.com/viewtopic.php?p=479963#479963 >> >> >> >> >> >> >> The Kolb-List Email Forum - >> Navigator to browse >> List Un/Subscription, >> 7-Day Browse, Chat, FAQ, >> - MATRONICS > WEB FORUMS - >> via the Web Forums! >> - NEW MATRONICS LIST > WIKI - >> Email List Wiki! >> - List Contribution > Web Site - >> support! >> > >> -Matt Dralle, List > Admin. >> >> >> >> >> >> >> >> > > The Kolb-List Email Forum - > Navigator to browse > List Un/Subscription, > 7-Day Browse, Chat, FAQ, > - MATRONICS WEB FORUMS - > via the Web Forums! > - NEW MATRONICS LIST WIKI - > Email List Wiki! > - List Contribution Web Site - > support! > > -Matt Dralle, List Admin. > > > > > > > >


    Message 5


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    Time: 12:56:13 PM PST US
    From: Bill Berle <victorbravo@sbcglobal.net>
    Subject: Re: High Thrust Line Question
    The replacement gear set does not fit into the same gearbox case. So unfortunately I cannot just buy two new gears and slide them into place. BUT... I am making progress towards one of the other potential solutions. After consulting with an experienced aircraft structures and metallurgy engineer, I believe I can make a simple prop extension that is held on with one central nut (a great big nut !) and remove the propeller before folding the wings. The key to doing this SAFELY is called the Belleville Spring, or Belleville Washer. It is a conical spring steel washer that becomes flat (like a regular washer) as it is tightened, providing a known, reliable tension/compression force over a reasonable range of installation torques. This means that I can install the propeller, tighten the nut until the Belleville Washer is more or less flat, and be confident that there is plenty of tension/compression in the propeller mounting without having to use a torque wrench, elaborate bolt stretch charts, etc. etc. This also provides a much more convenient and error-proof option instead of havign to torque six propeller bolts and safety wire the bolts, install six Cotter Pins, etc. All of this means I will be hopefully able to use a 4, 5, or 6 blade prop with the thrust line within Kolb's recommended distance from the tailboom. The only downside is that Kolbers around the world will never stop making fun of me for turning a simple airplane into a major engineering project :) The HKS engine is a VERY good quality engine and I believe the other Kolb/HKS owners will agree they love the engine. If you wish to use this engine on a Kolb, don't hold my mis-adventures against the engine... just make darn sure you get the 2.58 gearbox ! Bill Berle www.ezflaphandle.com - safety & performance upgrade for light aircraft www.grantstar.net - winning proposals for non-profit and for-profit entities -------------------------------------------- On Wed, 5/9/18, George Helton <gdhelton@gmail.com> wrote: Subject: Re: Kolb-List: Re: High Thrust Line Question To: kolb-list@matronics.com Date: Wednesday, May 9, 2018, 11:37 AM Helton <gdhelton@gmail.com> Bill, I know that this might sound crazy but, cant you just buy a different set of gears for the gearbox? Being a mechanic may be a benefit here but I cant imagine that HKS cant supply replacement parts. The gearbox case doesnt care what gears fit inside of it. If they dont, Id sure shy away from buying one. George Helton 1986 Firestar, FS100 14GDH Mesick, Michigan gdhelton@gmail.com Sent from my iPhone > On May 9, 2018, at 2:18 PM, Bill Berle <victorbravo@sbcglobal.net> wrote: > > --> Kolb-List message posted by: Bill Berle <victorbravo@sbcglobal.net> > > I have been pulling out what's left of my hair over this issue. I really don't want to quit, I LIKE the Kolb airframe and it will fit my mission well. I like the HKS fuel economy and improved reliability. I just wound up with the wrong gearbox on it and cannot afford to change it. > > What I have learned thus far is: > > 1) My 3.47 to 1 gearbox really wants to swing a larger propeller than what is actually "correct" for the height of the thrust line on the Kolb airframe. > > 2) Turning the gearbox upwards will solve the prop diameter problem, but it creates a thrust line that is higher than the Kolb factory thinks is advisable. > > 3) I could easily go to a 4 or 5 blade propeller, solves the gearbox AND thrust line problems, but that interferes with folding the wings. > > I have considered many possible solutions or "work-arounds" : > > 1) Get a 5 blade propeller and remove it after every flight, which would allow ALL of the problems to be solved, at the cost of additional time and effort every time I fly. This will cost the least of all the "solutions". > > 2) Remove the wings after every flight instead of folding the wings. This allows a 5 blade propeller to be used but adds complexity and requires me to build a complicated ground fixture to allow the wings to be removed and installed by myself alone. > > 3) Make a folding propeller, like the electric R/C model gliders have, where the blades fold rearward. This solves all of the problems, no complex ground equipment, but designing and manufacturing such a propeller will be prohibitvely expensive. > > 4) Buy another gearbox from HKS. This is the best solution mechanically, but I cannot afford it. > > 5) Turn the gearbox upwards, install the right propeller, and live with the possibly dangerous or funky flight handling of the airplane. > > Any other/better/wiser/workable ideas from the Kolb List are very very welcome! > > > > > Bill Berle > www.ezflaphandle.com - safety & performance upgrade for light aircraft > www.grantstar.net - winning proposals for non-profit and for-profit entities > > -------------------------------------------- > On Wed, 5/9/18, George Helton <gdhelton@gmail.com> wrote: > > Subject: Re: Kolb-List: Re: High Thrust Line Question > To: kolb-list@matronics.com > Date: Wednesday, May 9, 2018, 9:39 AM > > --> Kolb-List message posted by: George > Helton <gdhelton@gmail.com> > > Well Bill, thanks for bringing up the > topic. I replaced my little Rotax 377 with new low rpm Hirth > 2702 over the winter. I really hadnt measured the > distance between the prop hub and boom tube. You sparked my > interest so I stopped by my hanger this morning to check it > out. The Hirth uses a G50 gearbox with 2:29 to 1 ratio. > which translates to 2400 rpm prop speed @ the engines > max. HP rpm of 5500rpm. > Anyway, it measures 35.5 inches. This > is on a Kolb original Firestar. I did have to move the > engine forward 2.625 to compensate for the extra weight > of the new gear box. I went with a 64 3 blade Powerfin > prop set at 6.4 degrees of pitch. This setup gives me 3.5 > of clearance from the boom tube. Thanks for inspiring me to > check it out. Im sure there is a good combination > of prop out there for an HKS. > George Helton > 1986 Firestar, FS100 > 14GDH > Mesick, Michigan > gdhelton@gmail.com > > Sent from my iPhone > >> On May 8, 2018, at 11:08 PM, Bill > Berle <victorbravo@sbcglobal.net> > wrote: >> >> --> Kolb-List message posted > by: Bill Berle <victorbravo@sbcglobal.net> >> >> Everybody THANK YOU for taking > time for this discussion. >> >> I spoke to the Kolb factory today > by phone, and went out to the local UL flying field to see > an HKS engine run. >> >> Duane and Bryan at Kolb were asked > one specific question by me: What is the maximum > number of inches allowable or advisable between the center > of the propeller and the top of the tailboom? >> >> Bryan said that 36 inches is about > standard for a "normal" Firestar, and he would not want to > fly an airplane with that distance raised to 39 or 40 > inches. >> >> I went back to my hangar and > measured, and the distance on my Firestar would be over 40 > or 41 inches if I turned the gearbox upward. So if the Kolb > factory owner says 40 inches is too high, I can only be > humble and assume that I wouldn't want to fly it at 40 > inches either. If any of the highly experienced Kolbers on > this forum are flying with their thrust line 40 inches above > the tailboom, I REALLY would like to know about it pronto. >> >> As big of an ego as I have had a > few times in my life, and as much as I think of myself as a > reasonably skilled pilot, I don't need to be a test > pilot here and try to push any envelope at this early stage. > So if I can ask the Kolb ilst a favor... if any of you are > flying a Firestar with the engine thrust line 39 or 40 or 41 > incvhes above the tailboom please post this on the list and > let me know ifyou have any issues with the handling, > pitch-over, etc. >> >> Bill Berle >> www.ezflaphandle.com - > safety & performance upgrade for light aircraft >> www.grantstar.net > - winning proposals for non-profit and > for-profit entities >> >> > -------------------------------------------- >> On Tue, 5/8/18, Richard Pike > <thegreybaron@charter.net> > wrote: >> >> Subject: Kolb-List: Re: High > Thrust Line Question >> To: kolb-list@matronics.com >> Date: Tuesday, May 8, 2018, 4:38 > PM >> >> --> Kolb-List message posted > by: "Richard >> Pike" <thegreybaron@charter.net> >> >> Bill; notice the extent to which > Rick >> raised his engine. (Great > pictures) Maybe you can leave the >> gearbox down and raise the engine > up? >> >> -------- >> Richard Pike >> Kolb MKIII N420P (420ldPoops) >> Kingsport, TN 3TN0 >> >> Forgiving is tough, being forgiven > is >> wonderful, and God's grace really > is amazing. >> >> >> >> >> Read this topic online here: >> >> http://forums.matronics.com/viewtopic.php?p=479963#479963 >> >> >> >> >> >> >> The Kolb-List Email Forum - >> Navigator to browse >> List Un/Subscription, >> 7-Day Browse, Chat, FAQ, >> - MATRONICS > WEB FORUMS - >> via the Web Forums! >> - NEW MATRONICS LIST > WIKI - >> Email List Wiki! >> - List Contribution > Web Site - >> support! >> > >> -Matt Dralle, List > Admin. >> >> >> >> >> >> >> >> > > The Kolb-List Email Forum - > Navigator to browse > List Un/Subscription, > 7-Day Browse, Chat, FAQ, > - MATRONICS WEB FORUMS - > via the Web Forums! > - NEW MATRONICS LIST WIKI - > Email List Wiki! > - List Contribution Web Site - > support! > > -Matt Dralle, List Admin. > > > > > > > > The Kolb-List Email Forum - Navigator to browse List Un/Subscription, 7-Day Browse, Chat, FAQ, - MATRONICS WEB FORUMS - via the Web Forums! - NEW MATRONICS LIST WIKI - Email List Wiki! - List Contribution Web Site - support! -Matt Dralle, List Admin.


    Message 6


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    Time: 01:32:18 PM PST US
    From: "Jack Hart" <jbhart@onlyinternet.net>
    Subject: Re: High Thrust Line Question
    Bill, If you are worried about the effects of a high thrust line, you may want t o consider adding some area to your horizontal stabilizer. This should red uce some of the increased stick forces and tail work load. Jack B. Hart FF004 Winchester, IN ---------------------------------------- From: "Bill Berle" <victorbravo@sbcglobal.net> Sent: Wednesday, May 9, 2018 3:58 PM Subject: Re: Kolb-List: Re: High Thrust Line Question The replacement gear set does not fit into the same gearbox case. So unfort unately I cannot just buy two new gears and slide them into place. BUT... I am making progress towards one of the other potential solutions. A fter consulting with an experienced aircraft structures and metallurgy engi neer, I believe I can make a simple prop extension that is held on with one central nut (a great big nut !) and remove the propeller before folding th e wings. The key to doing this SAFELY is called the Belleville Spring, or Belleville Washer. It is a conical spring steel washer that becomes flat (like a regu lar washer) as it is tightened, providing a known, reliable tension/compres sion force over a reasonable range of installation torques. This means that I can install the propeller, tighten the nut until the Bell eville Washer is more or less flat, and be confident that there is plenty o f tension/compression in the propeller mounting without having to use a tor que wrench, elaborate bolt stretch charts, etc. etc. This also provides a m uch more convenient and error-proof option instead of havign to torque six propeller bolts and safety wire the bolts, install six Cotter Pins, etc. All of this means I will be hopefully able to use a 4, 5, or 6 blade prop w ith the thrust line within Kolb's recommended distance from the tailboom. The only downside is that Kolbers around the world will never stop making f un of me for turning a simple airplane into a major engineering project :) The HKS engine is a VERY good quality engine and I believe the other Kolb/H KS owners will agree they love the engine. If you wish to use this engine o n a Kolb, don't hold my mis-adventures against the engine... just make darn sure you get the 2.58 gearbox ! Bill Berle www.ezflaphandle.com - safety & performance upgrade for light aircraft www.grantstar.net - winning proposals for non-profit and for-prof it entities -------------------------------------------- On Wed, 5/9/18, George Helton <gdhelton@gmail.com> wrote: Subject: Re: Kolb-List: Re: High Thrust Line Question Helton <gdhelton@gmail.com> Bill, I know that this might sound crazy but, can't you just buy a different set of gears for the gearbox? Being a mechanic may be a benefit here but I can't imagine that HKS can't supply replacement parts. The gearbox case doesn't care what gears fit inside of it. If they don't, I'd sure shy away from buying one. George Helton 1986 Firestar, FS100 14GDH Mesick, Michigan gdhelton@gmail.com Sent from my iPhone > On May 9, 2018, at 2:18 PM, Bill Berle <victorbravo@sbcglobal.net> wrote: > > --> Kolb-List message posted by: Bill Berle <victorbravo@sbcglobal.net> > > I have been pulling out what's left of my hair over this issue. I really don't want to quit, I LIKE the Kolb airframe and it will fit my mission well. I like the HKS fuel economy and improved reliability. I just wound up with the wrong gearbox on it and cannot afford to change it. > > What I have learned thus far is: > > 1) My 3.47 to 1 gearbox really wants to swing a larger propeller than what is actually "correct" for the height of the thrust line on the Kolb airframe. > > 2) Turning the gearbox upwards will solve the prop diameter problem, but it creates a thrust line that is higher than the Kolb factory thinks is advisable. > > 3) I could easily go to a 4 or 5 blade propeller, solves the gearbox AND thrust line problems, but that interferes with folding the wings. > > I have considered many possible solutions or "work-arounds" : > > 1) Get a 5 blade propeller and remove it after every flight, which would allow ALL of the problems to be solved, at the cost of additional time and effort every time I fly. This will cost the least of all the "solutions". > > 2) Remove the wings after every flight instead of folding the wings. This allows a 5 blade propeller to be used but adds complexity and requires me to build a complicated ground fixture to allow the wings to be removed and installed by myself alone. > > 3) Make a folding propeller, like the electric R/C model gliders have, where the blades fold rearward. This solves all of the problems, no complex ground equipment, but designing and manufacturing such a propeller will be prohibitvely expensive. > > 4) Buy another gearbox from HKS. This is the best solution mechanically, but I cannot afford it. > > 5) Turn the gearbox upwards, install the right propeller, and live with the possibly dangerous or funky flight handling of the airplane. > > Any other/better/wiser/workable ideas from the Kolb List are very very welcome! > > > Bill Berle > www.ezflaphandle.com - safety & performance upgrade for light aircraft > www.grantstar.net - winning proposals for non-profit and for-profit entities > > -------------------------------------------- > On Wed, 5/9/18, George Helton <gdhelton@gmail.com> wrote: > > Subject: Re: Kolb-List: Re: High Thrust Line Question > To: kolb-list@matronics.com > Date: Wednesday, May 9, 2018, 9:39 AM > > --> Kolb-List message posted by: George > Helton <gdhelton@gmail.com> > > Well Bill, thanks for bringing up the > topic. I replaced my little Rotax 377 with new low rpm Hirth > 2702 over the winter. I really hadn't measured the > distance between the prop hub and boom tube. You sparked my > interest so I stopped by my hanger this morning to check it > out. The Hirth uses a G50 gearbox with 2:29 to 1 ratio. > which translates to 2400 rpm prop speed @ the engine's > max. HP rpm of 5500rpm. > Anyway, it measures 35.5 inches. This > is on a Kolb original Firestar. I did have to move the > engine forward 2.625" to compensate for the extra weight > of the new gear box. I went with a 64" 3 blade Powerfin > prop set at 6.4 degrees of pitch. This setup gives me 3.5" > of clearance from the boom tube. Thanks for inspiring me to > check it out. I'm sure there is a good combination > of prop out there for an HKS. > George Helton > 1986 Firestar, FS100 > 14GDH > Mesick, Michigan > gdhelton@gmail.com > > Sent from my iPhone > >> On May 8, 2018, at 11:08 PM, Bill > Berle <victorbravo@sbcglobal.net> > wrote: >> >> --> Kolb-List message posted > by: Bill Berle <victorbravo@sbcglobal.net> >> >> Everybody THANK YOU for taking > time for this discussion. >> >> I spoke to the Kolb factory today > by phone, and went out to the local UL flying field to see > an HKS engine run. >> >> Duane and Bryan at Kolb were asked > one specific question by me: What is the maximum > number of inches allowable or advisable between the center > of the propeller and the top of the tailboom? >> >> Bryan said that 36 inches is about > standard for a "normal" Firestar, and he would not want to > fly an airplane with that distance raised to 39 or 40 > inches. >> >> I went back to my hangar and > measured, and the distance on my Firestar would be over 40 > or 41 inches if I turned the gearbox upward. So if the Kolb > factory owner says 40 inches is too high, I can only be > humble and assume that I wouldn't want to fly it at 40 > inches either. If any of the highly experienced Kolbers on > this forum are flying with their thrust line 40 inches above > the tailboom, I REALLY would like to know about it pronto. >> >> As big of an ego as I have had a > few times in my life, and as much as I think of myself as a > reasonably skilled pilot, I don't need to be a test > pilot here and try to push any envelope at this early stage. > So if I can ask the Kolb ilst a favor... if any of you are > flying a Firestar with the engine thrust line 39 or 40 or 41 > incvhes above the tailboom please post this on the list and > let me know ifyou have any issues with the handling, > pitch-over, etc. >> >> Bill Berle >> www.ezflaphandle.com - > safety & performance upgrade for light aircraft >> www.grantstar.net > - winning proposals for non-profit and > for-profit entities >> >> > -------------------------------------------- >> On Tue, 5/8/18, Richard Pike > <thegreybaron@charter.net> > wrote: >> >> Subject: Kolb-List: Re: High > Thrust Line Question >> To: kolb-list@matronics.com >> Date: Tuesday, May 8, 2018, 4:38 > PM >> >> --> Kolb-List message posted > by: "Richard >> Pike" <thegreybaron@charter.net> >> >> Bill; notice the extent to which > Rick >> raised his engine. (Great > pictures) Maybe you can leave the >> gearbox down and raise the engine > up? >> >> -------- >> Richard Pike >> Kolb MKIII N420P (420ldPoops) >> Kingsport, TN 3TN0 >> >> Forgiving is tough, being forgiven > is >> wonderful, and God's grace really > is amazing. >> >> >> >> >> Read this topic online here: >> >> http://forums.matronics.com/viewtopic.php?p=479963#479963 >> >> >> >> >> >> >> The Kolb-List Email Forum - >> Navigator to browse >> List Un/Subscription, >> 7-Day Browse, Chat, FAQ, >> - MATRONICS > WEB FORUMS - >> via the Web Forums! >> - NEW MATRONICS LIST > WIKI - >> Email List Wiki! >> - List Contribution > Web Site - >> support! >> > >> -Matt Dralle, List > Admin. >> >> >> >> >> >> >> >> > > The Kolb-List Email Forum - > Navigator to browse > List Un/Subscription, > 7-Day Browse, Chat, FAQ, > - MATRONICS WEB FORUMS - > via the Web Forums! > - NEW MATRONICS LIST WIKI - > Email List Wiki! > - List Contribution Web Site - > support! > > -Matt Dralle, List Admin. > > The Kolb-List Email Forum - Navigator to browse List Un/Subscription, 7-Day Browse, Chat, FAQ, - MATRONICS WEB FORUMS - via the Web Forums! - NEW MATRONICS LIST WIKI - Email List Wiki! - List Contribution Web Site - support! -Matt Dralle, List Admin.


    Message 7


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    Time: 01:35:38 PM PST US
    From: "Jack Hart" <jbhart@onlyinternet.net>
    Subject: Re: High Thrust Line Question
    Bill, If you are worried about the effects of a high thrust line, you may want t o consider adding some area to your horizontal stabilizer. This should red uce some of the increased stick forces and tail work load. Jack B. Hart FF004 Winchester, IN ---------------------------------------- From: "Bill Berle" <victorbravo@sbcglobal.net> Sent: Wednesday, May 9, 2018 3:58 PM Subject: Re: Kolb-List: Re: High Thrust Line Question The replacement gear set does not fit into the same gearbox case. So unfort unately I cannot just buy two new gears and slide them into place. BUT... I am making progress towards one of the other potential solutions. A fter consulting with an experienced aircraft structures and metallurgy engi neer, I believe I can make a simple prop extension that is held on with one central nut (a great big nut !) and remove the propeller before folding th e wings. The key to doing this SAFELY is called the Belleville Spring, or Belleville Washer. It is a conical spring steel washer that becomes flat (like a regu lar washer) as it is tightened, providing a known, reliable tension/compres sion force over a reasonable range of installation torques. This means that I can install the propeller, tighten the nut until the Bell eville Washer is more or less flat, and be confident that there is plenty o f tension/compression in the propeller mounting without having to use a tor que wrench, elaborate bolt stretch charts, etc. etc. This also provides a m uch more convenient and error-proof option instead of havign to torque six propeller bolts and safety wire the bolts, install six Cotter Pins, etc. All of this means I will be hopefully able to use a 4, 5, or 6 blade prop w ith the thrust line within Kolb's recommended distance from the tailboom. The only downside is that Kolbers around the world will never stop making f un of me for turning a simple airplane into a major engineering project :) The HKS engine is a VERY good quality engine and I believe the other Kolb/H KS owners will agree they love the engine. If you wish to use this engine o n a Kolb, don't hold my mis-adventures against the engine... just make darn sure you get the 2.58 gearbox ! Bill Berle www.ezflaphandle.com - safety & performance upgrade for light aircraft www.grantstar.net - winning proposals for non-profit and for-prof it entities -------------------------------------------- On Wed, 5/9/18, George Helton <gdhelton@gmail.com> wrote: Subject: Re: Kolb-List: Re: High Thrust Line Question Helton <gdhelton@gmail.com> Bill, I know that this might sound crazy but, can't you just buy a different set of gears for the gearbox? Being a mechanic may be a benefit here but I can't imagine that HKS can't supply replacement parts. The gearbox case doesn't care what gears fit inside of it. If they don't, I'd sure shy away from buying one. George Helton 1986 Firestar, FS100 14GDH Mesick, Michigan gdhelton@gmail.com Sent from my iPhone > On May 9, 2018, at 2:18 PM, Bill Berle <victorbravo@sbcglobal.net> wrote: > > --> Kolb-List message posted by: Bill Berle <victorbravo@sbcglobal.net> > > I have been pulling out what's left of my hair over this issue. I really don't want to quit, I LIKE the Kolb airframe and it will fit my mission well. I like the HKS fuel economy and improved reliability. I just wound up with the wrong gearbox on it and cannot afford to change it. > > What I have learned thus far is: > > 1) My 3.47 to 1 gearbox really wants to swing a larger propeller than what is actually "correct" for the height of the thrust line on the Kolb airframe. > > 2) Turning the gearbox upwards will solve the prop diameter problem, but it creates a thrust line that is higher than the Kolb factory thinks is advisable. > > 3) I could easily go to a 4 or 5 blade propeller, solves the gearbox AND thrust line problems, but that interferes with folding the wings. > > I have considered many possible solutions or "work-arounds" : > > 1) Get a 5 blade propeller and remove it after every flight, which would allow ALL of the problems to be solved, at the cost of additional time and effort every time I fly. This will cost the least of all the "solutions". > > 2) Remove the wings after every flight instead of folding the wings. This allows a 5 blade propeller to be used but adds complexity and requires me to build a complicated ground fixture to allow the wings to be removed and installed by myself alone. > > 3) Make a folding propeller, like the electric R/C model gliders have, where the blades fold rearward. This solves all of the problems, no complex ground equipment, but designing and manufacturing such a propeller will be prohibitvely expensive. > > 4) Buy another gearbox from HKS. This is the best solution mechanically, but I cannot afford it. > > 5) Turn the gearbox upwards, install the right propeller, and live with the possibly dangerous or funky flight handling of the airplane. > > Any other/better/wiser/workable ideas from the Kolb List are very very welcome! > > > Bill Berle > www.ezflaphandle.com - safety & performance upgrade for light aircraft > www.grantstar.net - winning proposals for non-profit and for-profit entities > > -------------------------------------------- > On Wed, 5/9/18, George Helton <gdhelton@gmail.com> wrote: > > Subject: Re: Kolb-List: Re: High Thrust Line Question > To: kolb-list@matronics.com > Date: Wednesday, May 9, 2018, 9:39 AM > > --> Kolb-List message posted by: George > Helton <gdhelton@gmail.com> > > Well Bill, thanks for bringing up the > topic. I replaced my little Rotax 377 with new low rpm Hirth > 2702 over the winter. I really hadn't measured the > distance between the prop hub and boom tube. You sparked my > interest so I stopped by my hanger this morning to check it > out. The Hirth uses a G50 gearbox with 2:29 to 1 ratio. > which translates to 2400 rpm prop speed @ the engine's > max. HP rpm of 5500rpm. > Anyway, it measures 35.5 inches. This > is on a Kolb original Firestar. I did have to move the > engine forward 2.625" to compensate for the extra weight > of the new gear box. I went with a 64" 3 blade Powerfin > prop set at 6.4 degrees of pitch. This setup gives me 3.5" > of clearance from the boom tube. Thanks for inspiring me to > check it out. I'm sure there is a good combination > of prop out there for an HKS. > George Helton > 1986 Firestar, FS100 > 14GDH > Mesick, Michigan > gdhelton@gmail.com > > Sent from my iPhone > >> On May 8, 2018, at 11:08 PM, Bill > Berle <victorbravo@sbcglobal.net> > wrote: >> >> --> Kolb-List message posted > by: Bill Berle <victorbravo@sbcglobal.net> >> >> Everybody THANK YOU for taking > time for this discussion. >> >> I spoke to the Kolb factory today > by phone, and went out to the local UL flying field to see > an HKS engine run. >> >> Duane and Bryan at Kolb were asked > one specific question by me: What is the maximum > number of inches allowable or advisable between the center > of the propeller and the top of the tailboom? >> >> Bryan said that 36 inches is about > standard for a "normal" Firestar, and he would not want to > fly an airplane with that distance raised to 39 or 40 > inches. >> >> I went back to my hangar and > measured, and the distance on my Firestar would be over 40 > or 41 inches if I turned the gearbox upward. So if the Kolb > factory owner says 40 inches is too high, I can only be > humble and assume that I wouldn't want to fly it at 40 > inches either. If any of the highly experienced Kolbers on > this forum are flying with their thrust line 40 inches above > the tailboom, I REALLY would like to know about it pronto. >> >> As big of an ego as I have had a > few times in my life, and as much as I think of myself as a > reasonably skilled pilot, I don't need to be a test > pilot here and try to push any envelope at this early stage. > So if I can ask the Kolb ilst a favor... if any of you are > flying a Firestar with the engine thrust line 39 or 40 or 41 > incvhes above the tailboom please post this on the list and > let me know ifyou have any issues with the handling, > pitch-over, etc. >> >> Bill Berle >> www.ezflaphandle.com - > safety & performance upgrade for light aircraft >> www.grantstar.net > - winning proposals for non-profit and > for-profit entities >> >> > -------------------------------------------- >> On Tue, 5/8/18, Richard Pike > <thegreybaron@charter.net> > wrote: >> >> Subject: Kolb-List: Re: High > Thrust Line Question >> To: kolb-list@matronics.com >> Date: Tuesday, May 8, 2018, 4:38 > PM >> >> --> Kolb-List message posted > by: "Richard >> Pike" <thegreybaron@charter.net> >> >> Bill; notice the extent to which > Rick >> raised his engine. (Great > pictures) Maybe you can leave the >> gearbox down and raise the engine > up? >> >> -------- >> Richard Pike >> Kolb MKIII N420P (420ldPoops) >> Kingsport, TN 3TN0 >> >> Forgiving is tough, being forgiven > is >> wonderful, and God's grace really > is amazing. >> >> >> >> >> Read this topic online here: >> >> http://forums.matronics.com/viewtopic.php?p=479963#479963 >> >> >> >> >> >> >> The Kolb-List Email Forum - >> Navigator to browse >> List Un/Subscription, >> 7-Day Browse, Chat, FAQ, >> - MATRONICS > WEB FORUMS - >> via the Web Forums! >> - NEW MATRONICS LIST > WIKI - >> Email List Wiki! >> - List Contribution > Web Site - >> support! >> > >> -Matt Dralle, List > Admin. >> >> >> >> >> >> >> >> > > The Kolb-List Email Forum - > Navigator to browse > List Un/Subscription, > 7-Day Browse, Chat, FAQ, > - MATRONICS WEB FORUMS - > via the Web Forums! > - NEW MATRONICS LIST WIKI - > Email List Wiki! > - List Contribution Web Site - > support! > > -Matt Dralle, List Admin. > > The Kolb-List Email Forum - Navigator to browse List Un/Subscription, 7-Day Browse, Chat, FAQ, - MATRONICS WEB FORUMS - via the Web Forums! - NEW MATRONICS LIST WIKI - Email List Wiki! - List Contribution Web Site - support! -Matt Dralle, List Admin.


    Message 8


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    Time: 01:41:36 PM PST US
    From: "Jack Hart" <jbhart@onlyinternet.net>
    Subject: Re: High Thrust Line Question
    Bill, If you are worried about the effects of a high thrust line, you may want t o consider adding some area to your horizontal stabilizer. This should red uce some of the increased stick forces and tail work load. Jack B. Hart FF004 Winchester, IN ---------------------------------------- From: "Bill Berle" <victorbravo@sbcglobal.net> Sent: Wednesday, May 9, 2018 3:58 PM Subject: Re: Kolb-List: Re: High Thrust Line Question The replacement gear set does not fit into the same gearbox case. So unfort unately I cannot just buy two new gears and slide them into place. BUT... I am making progress towards one of the other potential solutions. A fter consulting with an experienced aircraft structures and metallurgy engi neer, I believe I can make a simple prop extension that is held on with one central nut (a great big nut !) and remove the propeller before folding th e wings. The key to doing this SAFELY is called the Belleville Spring, or Belleville Washer. It is a conical spring steel washer that becomes flat (like a regu lar washer) as it is tightened, providing a known, reliable tension/compres sion force over a reasonable range of installation torques. This means that I can install the propeller, tighten the nut until the Bell eville Washer is more or less flat, and be confident that there is plenty o f tension/compression in the propeller mounting without having to use a tor que wrench, elaborate bolt stretch charts, etc. etc. This also provides a m uch more convenient and error-proof option instead of havign to torque six propeller bolts and safety wire the bolts, install six Cotter Pins, etc. All of this means I will be hopefully able to use a 4, 5, or 6 blade prop w ith the thrust line within Kolb's recommended distance from the tailboom. The only downside is that Kolbers around the world will never stop making f un of me for turning a simple airplane into a major engineering project :) The HKS engine is a VERY good quality engine and I believe the other Kolb/H KS owners will agree they love the engine. If you wish to use this engine o n a Kolb, don't hold my mis-adventures against the engine... just make darn sure you get the 2.58 gearbox ! Bill Berle www.ezflaphandle.com - safety & performance upgrade for light aircraft www.grantstar.net - winning proposals for non-profit and for-prof it entities -------------------------------------------- On Wed, 5/9/18, George Helton <gdhelton@gmail.com> wrote: Subject: Re: Kolb-List: Re: High Thrust Line Question Helton <gdhelton@gmail.com> Bill, I know that this might sound crazy but, can't you just buy a different set of gears for the gearbox? Being a mechanic may be a benefit here but I can't imagine that HKS can't supply replacement parts. The gearbox case doesn't care what gears fit inside of it. If they don't, I'd sure shy away from buying one. George Helton 1986 Firestar, FS100 14GDH Mesick, Michigan gdhelton@gmail.com Sent from my iPhone > On May 9, 2018, at 2:18 PM, Bill Berle <victorbravo@sbcglobal.net> wrote: > > --> Kolb-List message posted by: Bill Berle <victorbravo@sbcglobal.net> > > I have been pulling out what's left of my hair over this issue. I really don't want to quit, I LIKE the Kolb airframe and it will fit my mission well. I like the HKS fuel economy and improved reliability. I just wound up with the wrong gearbox on it and cannot afford to change it. > > What I have learned thus far is: > > 1) My 3.47 to 1 gearbox really wants to swing a larger propeller than what is actually "correct" for the height of the thrust line on the Kolb airframe. > > 2) Turning the gearbox upwards will solve the prop diameter problem, but it creates a thrust line that is higher than the Kolb factory thinks is advisable. > > 3) I could easily go to a 4 or 5 blade propeller, solves the gearbox AND thrust line problems, but that interferes with folding the wings. > > I have considered many possible solutions or "work-arounds" : > > 1) Get a 5 blade propeller and remove it after every flight, which would allow ALL of the problems to be solved, at the cost of additional time and effort every time I fly. This will cost the least of all the "solutions". > > 2) Remove the wings after every flight instead of folding the wings. This allows a 5 blade propeller to be used but adds complexity and requires me to build a complicated ground fixture to allow the wings to be removed and installed by myself alone. > > 3) Make a folding propeller, like the electric R/C model gliders have, where the blades fold rearward. This solves all of the problems, no complex ground equipment, but designing and manufacturing such a propeller will be prohibitvely expensive. > > 4) Buy another gearbox from HKS. This is the best solution mechanically, but I cannot afford it. > > 5) Turn the gearbox upwards, install the right propeller, and live with the possibly dangerous or funky flight handling of the airplane. > > Any other/better/wiser/workable ideas from the Kolb List are very very welcome! > > > Bill Berle > www.ezflaphandle.com - safety & performance upgrade for light aircraft > www.grantstar.net - winning proposals for non-profit and for-profit entities > > -------------------------------------------- > On Wed, 5/9/18, George Helton <gdhelton@gmail.com> wrote: > > Subject: Re: Kolb-List: Re: High Thrust Line Question > To: kolb-list@matronics.com > Date: Wednesday, May 9, 2018, 9:39 AM > > --> Kolb-List message posted by: George > Helton <gdhelton@gmail.com> > > Well Bill, thanks for bringing up the > topic. I replaced my little Rotax 377 with new low rpm Hirth > 2702 over the winter. I really hadn't measured the > distance between the prop hub and boom tube. You sparked my > interest so I stopped by my hanger this morning to check it > out. The Hirth uses a G50 gearbox with 2:29 to 1 ratio. > which translates to 2400 rpm prop speed @ the engine's > max. HP rpm of 5500rpm. > Anyway, it measures 35.5 inches. This > is on a Kolb original Firestar. I did have to move the > engine forward 2.625" to compensate for the extra weight > of the new gear box. I went with a 64" 3 blade Powerfin > prop set at 6.4 degrees of pitch. This setup gives me 3.5" > of clearance from the boom tube. Thanks for inspiring me to > check it out. I'm sure there is a good combination > of prop out there for an HKS. > George Helton > 1986 Firestar, FS100 > 14GDH > Mesick, Michigan > gdhelton@gmail.com > > Sent from my iPhone > >> On May 8, 2018, at 11:08 PM, Bill > Berle <victorbravo@sbcglobal.net> > wrote: >> >> --> Kolb-List message posted > by: Bill Berle <victorbravo@sbcglobal.net> >> >> Everybody THANK YOU for taking > time for this discussion. >> >> I spoke to the Kolb factory today > by phone, and went out to the local UL flying field to see > an HKS engine run. >> >> Duane and Bryan at Kolb were asked > one specific question by me: What is the maximum > number of inches allowable or advisable between the center > of the propeller and the top of the tailboom? >> >> Bryan said that 36 inches is about > standard for a "normal" Firestar, and he would not want to > fly an airplane with that distance raised to 39 or 40 > inches. >> >> I went back to my hangar and > measured, and the distance on my Firestar would be over 40 > or 41 inches if I turned the gearbox upward. So if the Kolb > factory owner says 40 inches is too high, I can only be > humble and assume that I wouldn't want to fly it at 40 > inches either. If any of the highly experienced Kolbers on > this forum are flying with their thrust line 40 inches above > the tailboom, I REALLY would like to know about it pronto. >> >> As big of an ego as I have had a > few times in my life, and as much as I think of myself as a > reasonably skilled pilot, I don't need to be a test > pilot here and try to push any envelope at this early stage. > So if I can ask the Kolb ilst a favor... if any of you are > flying a Firestar with the engine thrust line 39 or 40 or 41 > incvhes above the tailboom please post this on the list and > let me know ifyou have any issues with the handling, > pitch-over, etc. >> >> Bill Berle >> www.ezflaphandle.com - > safety & performance upgrade for light aircraft >> www.grantstar.net > - winning proposals for non-profit and > for-profit entities >> >> > -------------------------------------------- >> On Tue, 5/8/18, Richard Pike > <thegreybaron@charter.net> > wrote: >> >> Subject: Kolb-List: Re: High > Thrust Line Question >> To: kolb-list@matronics.com >> Date: Tuesday, May 8, 2018, 4:38 > PM >> >> --> Kolb-List message posted > by: "Richard >> Pike" <thegreybaron@charter.net> >> >> Bill; notice the extent to which > Rick >> raised his engine. (Great > pictures) Maybe you can leave the >> gearbox down and raise the engine > up? >> >> -------- >> Richard Pike >> Kolb MKIII N420P (420ldPoops) >> Kingsport, TN 3TN0 >> >> Forgiving is tough, being forgiven > is >> wonderful, and God's grace really > is amazing. >> >> >> >> >> Read this topic online here: >> >> http://forums.matronics.com/viewtopic.php?p=479963#479963 >> >> >> >> >> >> >> The Kolb-List Email Forum - >> Navigator to browse >> List Un/Subscription, >> 7-Day Browse, Chat, FAQ, >> - MATRONICS > WEB FORUMS - >> via the Web Forums! >> - NEW MATRONICS LIST > WIKI - >> Email List Wiki! >> - List Contribution > Web Site - >> support! >> > >> -Matt Dralle, List > Admin. >> >> >> >> >> >> >> >> > > The Kolb-List Email Forum - > Navigator to browse > List Un/Subscription, > 7-Day Browse, Chat, FAQ, > - MATRONICS WEB FORUMS - > via the Web Forums! > - NEW MATRONICS LIST WIKI - > Email List Wiki! > - List Contribution Web Site - > support! > > -Matt Dralle, List Admin. > > The Kolb-List Email Forum - Navigator to browse List Un/Subscription, 7-Day Browse, Chat, FAQ, - MATRONICS WEB FORUMS - via the Web Forums! - NEW MATRONICS LIST WIKI - Email List Wiki! - List Contribution Web Site - support! -Matt Dralle, List Admin.


    Message 9


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    Time: 01:57:43 PM PST US
    From: "Jack Hart" <jbhart@onlyinternet.net>
    Subject: Re: High Thrust Line Question
    Bill, If you are worried about the effects of a high thrust line, you may want t o consider adding some area to your horizontal stabilizer. This should red uce some of the increased stick forces and tail work load. Jack B. Hart FF004 Winchester, IN ---------------------------------------- From: "Bill Berle" <victorbravo@sbcglobal.net> Sent: Wednesday, May 9, 2018 3:58 PM Subject: Re: Kolb-List: Re: High Thrust Line Question The replacement gear set does not fit into the same gearbox case. So unfort unately I cannot just buy two new gears and slide them into place. BUT... I am making progress towards one of the other potential solutions. A fter consulting with an experienced aircraft structures and metallurgy engi neer, I believe I can make a simple prop extension that is held on with one central nut (a great big nut !) and remove the propeller before folding th e wings. The key to doing this SAFELY is called the Belleville Spring, or Belleville Washer. It is a conical spring steel washer that becomes flat (like a regu lar washer) as it is tightened, providing a known, reliable tension/compres sion force over a reasonable range of installation torques. This means that I can install the propeller, tighten the nut until the Bell eville Washer is more or less flat, and be confident that there is plenty o f tension/compression in the propeller mounting without having to use a tor que wrench, elaborate bolt stretch charts, etc. etc. This also provides a m uch more convenient and error-proof option instead of havign to torque six propeller bolts and safety wire the bolts, install six Cotter Pins, etc. All of this means I will be hopefully able to use a 4, 5, or 6 blade prop w ith the thrust line within Kolb's recommended distance from the tailboom. The only downside is that Kolbers around the world will never stop making f un of me for turning a simple airplane into a major engineering project :) The HKS engine is a VERY good quality engine and I believe the other Kolb/H KS owners will agree they love the engine. If you wish to use this engine o n a Kolb, don't hold my mis-adventures against the engine... just make darn sure you get the 2.58 gearbox ! Bill Berle www.ezflaphandle.com - safety & performance upgrade for light aircraft www.grantstar.net - winning proposals for non-profit and for-prof it entities -------------------------------------------- On Wed, 5/9/18, George Helton <gdhelton@gmail.com> wrote: Subject: Re: Kolb-List: Re: High Thrust Line Question Helton <gdhelton@gmail.com> Bill, I know that this might sound crazy but, can't you just buy a different set of gears for the gearbox? Being a mechanic may be a benefit here but I can't imagine that HKS can't supply replacement parts. The gearbox case doesn't care what gears fit inside of it. If they don't, I'd sure shy away from buying one. George Helton 1986 Firestar, FS100 14GDH Mesick, Michigan gdhelton@gmail.com Sent from my iPhone > On May 9, 2018, at 2:18 PM, Bill Berle <victorbravo@sbcglobal.net> wrote: > > --> Kolb-List message posted by: Bill Berle <victorbravo@sbcglobal.net> > > I have been pulling out what's left of my hair over this issue. I really don't want to quit, I LIKE the Kolb airframe and it will fit my mission well. I like the HKS fuel economy and improved reliability. I just wound up with the wrong gearbox on it and cannot afford to change it. > > What I have learned thus far is: > > 1) My 3.47 to 1 gearbox really wants to swing a larger propeller than what is actually "correct" for the height of the thrust line on the Kolb airframe. > > 2) Turning the gearbox upwards will solve the prop diameter problem, but it creates a thrust line that is higher than the Kolb factory thinks is advisable. > > 3) I could easily go to a 4 or 5 blade propeller, solves the gearbox AND thrust line problems, but that interferes with folding the wings. > > I have considered many possible solutions or "work-arounds" : > > 1) Get a 5 blade propeller and remove it after every flight, which would allow ALL of the problems to be solved, at the cost of additional time and effort every time I fly. This will cost the least of all the "solutions". > > 2) Remove the wings after every flight instead of folding the wings. This allows a 5 blade propeller to be used but adds complexity and requires me to build a complicated ground fixture to allow the wings to be removed and installed by myself alone. > > 3) Make a folding propeller, like the electric R/C model gliders have, where the blades fold rearward. This solves all of the problems, no complex ground equipment, but designing and manufacturing such a propeller will be prohibitvely expensive. > > 4) Buy another gearbox from HKS. This is the best solution mechanically, but I cannot afford it. > > 5) Turn the gearbox upwards, install the right propeller, and live with the possibly dangerous or funky flight handling of the airplane. > > Any other/better/wiser/workable ideas from the Kolb List are very very welcome! > > > Bill Berle > www.ezflaphandle.com - safety & performance upgrade for light aircraft > www.grantstar.net - winning proposals for non-profit and for-profit entities > > -------------------------------------------- > On Wed, 5/9/18, George Helton <gdhelton@gmail.com> wrote: > > Subject: Re: Kolb-List: Re: High Thrust Line Question > To: kolb-list@matronics.com > Date: Wednesday, May 9, 2018, 9:39 AM > > --> Kolb-List message posted by: George > Helton <gdhelton@gmail.com> > > Well Bill, thanks for bringing up the > topic. I replaced my little Rotax 377 with new low rpm Hirth > 2702 over the winter. I really hadn't measured the > distance between the prop hub and boom tube. You sparked my > interest so I stopped by my hanger this morning to check it > out. The Hirth uses a G50 gearbox with 2:29 to 1 ratio. > which translates to 2400 rpm prop speed @ the engine's > max. HP rpm of 5500rpm. > Anyway, it measures 35.5 inches. This > is on a Kolb original Firestar. I did have to move the > engine forward 2.625" to compensate for the extra weight > of the new gear box. I went with a 64" 3 blade Powerfin > prop set at 6.4 degrees of pitch. This setup gives me 3.5" > of clearance from the boom tube. Thanks for inspiring me to > check it out. I'm sure there is a good combination > of prop out there for an HKS. > George Helton > 1986 Firestar, FS100 > 14GDH > Mesick, Michigan > gdhelton@gmail.com > > Sent from my iPhone > >> On May 8, 2018, at 11:08 PM, Bill > Berle <victorbravo@sbcglobal.net> > wrote: >> >> --> Kolb-List message posted > by: Bill Berle <victorbravo@sbcglobal.net> >> >> Everybody THANK YOU for taking > time for this discussion. >> >> I spoke to the Kolb factory today > by phone, and went out to the local UL flying field to see > an HKS engine run. >> >> Duane and Bryan at Kolb were asked > one specific question by me: What is the maximum > number of inches allowable or advisable between the center > of the propeller and the top of the tailboom? >> >> Bryan said that 36 inches is about > standard for a "normal" Firestar, and he would not want to > fly an airplane with that distance raised to 39 or 40 > inches. >> >> I went back to my hangar and > measured, and the distance on my Firestar would be over 40 > or 41 inches if I turned the gearbox upward. So if the Kolb > factory owner says 40 inches is too high, I can only be > humble and assume that I wouldn't want to fly it at 40 > inches either. If any of the highly experienced Kolbers on > this forum are flying with their thrust line 40 inches above > the tailboom, I REALLY would like to know about it pronto. >> >> As big of an ego as I have had a > few times in my life, and as much as I think of myself as a > reasonably skilled pilot, I don't need to be a test > pilot here and try to push any envelope at this early stage. > So if I can ask the Kolb ilst a favor... if any of you are > flying a Firestar with the engine thrust line 39 or 40 or 41 > incvhes above the tailboom please post this on the list and > let me know ifyou have any issues with the handling, > pitch-over, etc. >> >> Bill Berle >> www.ezflaphandle.com - > safety & performance upgrade for light aircraft >> www.grantstar.net > - winning proposals for non-profit and > for-profit entities >> >> > -------------------------------------------- >> On Tue, 5/8/18, Richard Pike > <thegreybaron@charter.net> > wrote: >> >> Subject: Kolb-List: Re: High > Thrust Line Question >> To: kolb-list@matronics.com >> Date: Tuesday, May 8, 2018, 4:38 > PM >> >> --> Kolb-List message posted > by: "Richard >> Pike" <thegreybaron@charter.net> >> >> Bill; notice the extent to which > Rick >> raised his engine. (Great > pictures) Maybe you can leave the >> gearbox down and raise the engine > up? >> >> -------- >> Richard Pike >> Kolb MKIII N420P (420ldPoops) >> Kingsport, TN 3TN0 >> >> Forgiving is tough, being forgiven > is >> wonderful, and God's grace really > is amazing. >> >> >> >> >> Read this topic online here: >> >> http://forums.matronics.com/viewtopic.php?p=479963#479963 >> >> >> >> >> >> >> The Kolb-List Email Forum - >> Navigator to browse >> List Un/Subscription, >> 7-Day Browse, Chat, FAQ, >> - MATRONICS > WEB FORUMS - >> via the Web Forums! >> - NEW MATRONICS LIST > WIKI - >> Email List Wiki! >> - List Contribution > Web Site - >> support! >> > >> -Matt Dralle, List > Admin. >> >> >> >> >> >> >> >> > > The Kolb-List Email Forum - > Navigator to browse > List Un/Subscription, > 7-Day Browse, Chat, FAQ, > - MATRONICS WEB FORUMS - > via the Web Forums! > - NEW MATRONICS LIST WIKI - > Email List Wiki! > - List Contribution Web Site - > support! > > -Matt Dralle, List Admin. > > The Kolb-List Email Forum - Navigator to browse List Un/Subscription, 7-Day Browse, Chat, FAQ, - MATRONICS WEB FORUMS - via the Web Forums! - NEW MATRONICS LIST WIKI - Email List Wiki! - List Contribution Web Site - support! -Matt Dralle, List Admin.


    Message 10


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    Time: 02:10:15 PM PST US
    From: George Helton <gdhelton@gmail.com>
    Subject: Re: High Thrust Line Question
    I agree with you that the HKS is great engine. I considered it when I was shopping for a new engine for my original Firestar. But, after talking to Bryan at Kolb it wasnt to be. He didnt think the original Firestars had a strong enough cage assembly ( chromoly steel tubing wall thicknesses)to handle the torque that the HKS produces. I went along with his opinion. We used Belleville washers for many years in heavy equipment powershift transmissions as an alternative to the piston return springs inside the hydraulic clutch packs They worked great. They would fail eventually like anything else. But, it took ten of thousands of cycles. Good luck on the idea. George Helton 1986 Firestar, FS100 14GDH Mesick, Michigan gdhelton@gmail.com Sent from my iPhone > On May 9, 2018, at 3:54 PM, Bill Berle <victorbravo@sbcglobal.net> wrote: > > > The replacement gear set does not fit into the same gearbox case. So unfortunately I cannot just buy two new gears and slide them into place. > > BUT... I am making progress towards one of the other potential solutions. After consulting with an experienced aircraft structures and metallurgy engineer, I believe I can make a simple prop extension that is held on with one central nut (a great big nut !) and remove the propeller before folding the wings. > > The key to doing this SAFELY is called the Belleville Spring, or Belleville Washer. It is a conical spring steel washer that becomes flat (like a regular washer) as it is tightened, providing a known, reliable tension/compression force over a reasonable range of installation torques. > > This means that I can install the propeller, tighten the nut until the Belleville Washer is more or less flat, and be confident that there is plenty of tension/compression in the propeller mounting without having to use a torque wrench, elaborate bolt stretch charts, etc. etc. This also provides a much more convenient and error-proof option instead of havign to torque six propeller bolts and safety wire the bolts, install six Cotter Pins, etc. > > All of this means I will be hopefully able to use a 4, 5, or 6 blade prop with the thrust line within Kolb's recommended distance from the tailboom. > > The only downside is that Kolbers around the world will never stop making fun of me for turning a simple airplane into a major engineering project :) > > The HKS engine is a VERY good quality engine and I believe the other Kolb/HKS owners will agree they love the engine. If you wish to use this engine on a Kolb, don't hold my mis-adventures against the engine... just make darn sure you get the 2.58 gearbox ! > > Bill Berle > www.ezflaphandle.com - safety & performance upgrade for light aircraft > www.grantstar.net - winning proposals for non-profit and for-profit entities > > -------------------------------------------- > On Wed, 5/9/18, George Helton <gdhelton@gmail.com> wrote: > > Subject: Re: Kolb-List: Re: High Thrust Line Question > To: kolb-list@matronics.com > Date: Wednesday, May 9, 2018, 11:37 AM > > Helton <gdhelton@gmail.com> > > Bill, I know that this might sound > crazy but, cant you just buy a different set of gears for > the gearbox? Being a mechanic may be a benefit here but I > cant imagine that HKS cant supply replacement parts. > The gearbox case doesnt care what gears fit inside of it. > > If they dont, Id sure shy away > from buying one. > George Helton > 1986 Firestar, FS100 > 14GDH > Mesick, Michigan > gdhelton@gmail.com > > Sent from my iPhone > >> On May 9, 2018, at 2:18 PM, Bill > Berle <victorbravo@sbcglobal.net> > wrote: >> >> --> Kolb-List message posted > by: Bill Berle <victorbravo@sbcglobal.net> >> >> I have been pulling out what's > left of my hair over this issue. I really don't want to > quit, I LIKE the Kolb airframe and it will fit my mission > well. I like the HKS fuel economy and improved reliability. > I just wound up with the wrong gearbox on it and cannot > afford to change it. >> >> What I have learned thus far is: >> >> 1) My 3.47 to 1 gearbox really > wants to swing a larger propeller than what is > actually "correct" for the height of the thrust line > on the Kolb airframe. >> >> 2) Turning the gearbox upwards > will solve the prop diameter problem, but it creates a > thrust line that is higher than the Kolb factory thinks is > advisable. >> >> 3) I could easily go to a 4 or 5 > blade propeller, solves the gearbox AND thrust line > problems, but that interferes with folding the wings. >> >> I have considered many possible > solutions or "work-arounds" : >> >> 1) Get a 5 blade propeller and > remove it after every flight, which would allow ALL of the > problems to be solved, at the cost of additional time and > effort every time I fly. This will cost the least of all the > "solutions". >> >> 2) Remove the wings after every > flight instead of folding the wings. This allows a 5 blade > propeller to be used but adds complexity and requires me to > build a complicated ground fixture to allow the wings to be > removed and installed by myself alone. >> >> 3) Make a folding propeller, like > the electric R/C model gliders have, where the blades fold > rearward. This solves all of the problems, no complex ground > equipment, but designing and manufacturing such a propeller > will be prohibitvely expensive. >> >> 4) Buy another gearbox from HKS. > This is the best solution mechanically, but I cannot afford > it. >> >> 5) Turn the gearbox upwards, > install the right propeller, and live with the possibly > dangerous or funky flight handling of the airplane. >> >> Any other/better/wiser/workable > ideas from the Kolb List are very very welcome! >> >> >> >> >> Bill Berle >> www.ezflaphandle.com - > safety & performance upgrade for light aircraft >> www.grantstar.net > - winning proposals for non-profit and > for-profit entities >> >> > -------------------------------------------- >> On Wed, 5/9/18, George Helton > <gdhelton@gmail.com> > wrote: >> >> Subject: Re: Kolb-List: Re: High > Thrust Line Question >> To: kolb-list@matronics.com >> Date: Wednesday, May 9, 2018, 9:39 > AM >> >> --> Kolb-List message posted > by: George >> Helton <gdhelton@gmail.com> >> >> Well Bill, thanks for bringing up > the >> topic. I replaced my little Rotax > 377 with new low rpm Hirth >> 2702 over the winter. I really > hadnt measured the >> distance between the prop hub and > boom tube. You sparked my >> interest so I stopped by my hanger > this morning to check it >> out. The Hirth uses a G50 gearbox > with 2:29 to 1 ratio. >> which translates to 2400 rpm prop > speed @ the engines >> max. HP rpm of 5500rpm. >> Anyway, it measures 35.5 inches. > This >> is on a Kolb original Firestar. I > did have to move the >> engine forward 2.625 to > compensate for the extra weight >> of the new gear box. I went with a > 64 3 blade Powerfin >> prop set at 6.4 degrees of pitch. > This setup gives me 3.5 >> of clearance from the boom tube. > Thanks for inspiring me to >> check it out. Im sure > there is a good combination >> of prop out there for an HKS. >> George Helton >> 1986 Firestar, FS100 >> 14GDH >> Mesick, Michigan >> gdhelton@gmail.com >> >> Sent from my iPhone >> >>> On May 8, 2018, at 11:08 PM, > Bill >> Berle <victorbravo@sbcglobal.net> >> wrote: >>> >>> --> Kolb-List message > posted >> by: Bill Berle <victorbravo@sbcglobal.net> >>> >>> Everybody THANK YOU for > taking >> time for this discussion. >>> >>> I spoke to the Kolb factory > today >> by phone, and went out to the > local UL flying field to see >> an HKS engine run. >>> >>> Duane and Bryan at Kolb were > asked >> one specific question by me: > What is the maximum >> number of inches allowable or > advisable between the center >> of the propeller and the top of > the tailboom? >>> >>> Bryan said that 36 inches is > about >> standard for a "normal" Firestar, > and he would not want to >> fly an airplane with that distance > raised to 39 or 40 >> inches. >>> >>> I went back to my hangar and >> measured, and the distance on my > Firestar would be over 40 >> or 41 inches if I turned the > gearbox upward. So if the Kolb >> factory owner says 40 inches is > too high, I can only be >> humble and assume that I wouldn't > want to fly it at 40 >> inches either. If any of the > highly experienced Kolbers on >> this forum are flying with their > thrust line 40 inches above >> the tailboom, I REALLY would like > to know about it pronto. >>> >>> As big of an ego as I have had > a >> few times in my life, and as much > as I think of myself as a >> reasonably skilled pilot, I > don't need to be a test >> pilot here and try to push any > envelope at this early stage. >> So if I can ask the Kolb ilst a > favor... if any of you are >> flying a Firestar with the engine > thrust line 39 or 40 or 41 >> incvhes above the tailboom please > post this on the list and >> let me know ifyou have any issues > with the handling, >> pitch-over, etc. >>> >>> Bill Berle >>> www.ezflaphandle.com - >> safety & performance upgrade > for light aircraft >>> www.grantstar.net >> - > winning proposals for non-profit and >> for-profit entities >>> >>> >> > -------------------------------------------- >>> On Tue, 5/8/18, Richard Pike >> <thegreybaron@charter.net> >> wrote: >>> >>> Subject: Kolb-List: Re: High >> Thrust Line Question >>> To: kolb-list@matronics.com >>> Date: Tuesday, May 8, 2018, > 4:38 >> PM >>> >>> --> Kolb-List message > posted >> by: "Richard >>> Pike" <thegreybaron@charter.net> >>> >>> Bill; notice the extent to > which >> Rick >>> raised his engine. (Great >> pictures) Maybe you can leave the >>> gearbox down and raise the > engine >> up? >>> >>> -------- >>> Richard Pike >>> Kolb MKIII N420P (420ldPoops) >>> Kingsport, TN 3TN0 >>> >>> Forgiving is tough, being > forgiven >> is >>> wonderful, and God's grace > really >> is amazing. >>> >>> >>> >>> >>> Read this topic online here: >>> >>> http://forums.matronics.com/viewtopic.php?p=479963#479963 >>> >>> >>> >>> >>> >>> >>> The Kolb-List Email Forum - >>> Navigator to browse >>> List Un/Subscription, >>> 7-Day Browse, Chat, FAQ, >>> - > MATRONICS >> WEB FORUMS - >>> via the Web Forums! >>> - NEW > MATRONICS LIST >> WIKI - >>> Email List Wiki! >>> - List > Contribution >> Web Site - >>> support! >>> > >> >>> -Matt > Dralle, List >> Admin. >>> >>> >>> >>> >>> >>> >>> >>> >> >> The Kolb-List Email Forum - >> Navigator to browse >> List Un/Subscription, >> 7-Day Browse, Chat, FAQ, >> - MATRONICS > WEB FORUMS - >> via the Web Forums! >> - NEW MATRONICS LIST > WIKI - >> Email List Wiki! >> - List Contribution > Web Site - >> support! >> > >> -Matt Dralle, List > Admin. >> >> >> >> >> >> >> >> > > The Kolb-List Email Forum - > Navigator to browse > List Un/Subscription, > 7-Day Browse, Chat, FAQ, > - MATRONICS WEB FORUMS - > via the Web Forums! > - NEW MATRONICS LIST WIKI - > Email List Wiki! > - List Contribution Web Site - > support! > > -Matt Dralle, List Admin. > > > > > > > >


    Message 11


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    Time: 02:28:47 PM PST US
    From: "Jack Hart" <jbhart@onlyinternet.net>
    Subject: Re: High Thrust Line Question
    Bill, If you are worried about the effects of a high thrust line, you may want t o consider adding some area to your horizontal stabilizer. This should red uce some of the increased stick forces and tail work load. Jack B. Hart FF004 Winchester, IN ---------------------------------------- From: "Bill Berle" <victorbravo@sbcglobal.net> Sent: Wednesday, May 9, 2018 3:58 PM Subject: Re: Kolb-List: Re: High Thrust Line Question The replacement gear set does not fit into the same gearbox case. So unfort unately I cannot just buy two new gears and slide them into place. BUT... I am making progress towards one of the other potential solutions. A fter consulting with an experienced aircraft structures and metallurgy engi neer, I believe I can make a simple prop extension that is held on with one central nut (a great big nut !) and remove the propeller before folding th e wings. The key to doing this SAFELY is called the Belleville Spring, or Belleville Washer. It is a conical spring steel washer that becomes flat (like a regu lar washer) as it is tightened, providing a known, reliable tension/compres sion force over a reasonable range of installation torques. This means that I can install the propeller, tighten the nut until the Bell eville Washer is more or less flat, and be confident that there is plenty o f tension/compression in the propeller mounting without having to use a tor que wrench, elaborate bolt stretch charts, etc. etc. This also provides a m uch more convenient and error-proof option instead of havign to torque six propeller bolts and safety wire the bolts, install six Cotter Pins, etc. All of this means I will be hopefully able to use a 4, 5, or 6 blade prop w ith the thrust line within Kolb's recommended distance from the tailboom. The only downside is that Kolbers around the world will never stop making f un of me for turning a simple airplane into a major engineering project :) The HKS engine is a VERY good quality engine and I believe the other Kolb/H KS owners will agree they love the engine. If you wish to use this engine o n a Kolb, don't hold my mis-adventures against the engine... just make darn sure you get the 2.58 gearbox ! Bill Berle www.ezflaphandle.com - safety & performance upgrade for light aircraft www.grantstar.net - winning proposals for non-profit and for-prof it entities -------------------------------------------- On Wed, 5/9/18, George Helton <gdhelton@gmail.com> wrote: Subject: Re: Kolb-List: Re: High Thrust Line Question Helton <gdhelton@gmail.com> Bill, I know that this might sound crazy but, can't you just buy a different set of gears for the gearbox? Being a mechanic may be a benefit here but I can't imagine that HKS can't supply replacement parts. The gearbox case doesn't care what gears fit inside of it. If they don't, I'd sure shy away from buying one. George Helton 1986 Firestar, FS100 14GDH Mesick, Michigan gdhelton@gmail.com Sent from my iPhone > On May 9, 2018, at 2:18 PM, Bill Berle <victorbravo@sbcglobal.net> wrote: > > --> Kolb-List message posted by: Bill Berle <victorbravo@sbcglobal.net> > > I have been pulling out what's left of my hair over this issue. I really don't want to quit, I LIKE the Kolb airframe and it will fit my mission well. I like the HKS fuel economy and improved reliability. I just wound up with the wrong gearbox on it and cannot afford to change it. > > What I have learned thus far is: > > 1) My 3.47 to 1 gearbox really wants to swing a larger propeller than what is actually "correct" for the height of the thrust line on the Kolb airframe. > > 2) Turning the gearbox upwards will solve the prop diameter problem, but it creates a thrust line that is higher than the Kolb factory thinks is advisable. > > 3) I could easily go to a 4 or 5 blade propeller, solves the gearbox AND thrust line problems, but that interferes with folding the wings. > > I have considered many possible solutions or "work-arounds" : > > 1) Get a 5 blade propeller and remove it after every flight, which would allow ALL of the problems to be solved, at the cost of additional time and effort every time I fly. This will cost the least of all the "solutions". > > 2) Remove the wings after every flight instead of folding the wings. This allows a 5 blade propeller to be used but adds complexity and requires me to build a complicated ground fixture to allow the wings to be removed and installed by myself alone. > > 3) Make a folding propeller, like the electric R/C model gliders have, where the blades fold rearward. This solves all of the problems, no complex ground equipment, but designing and manufacturing such a propeller will be prohibitvely expensive. > > 4) Buy another gearbox from HKS. This is the best solution mechanically, but I cannot afford it. > > 5) Turn the gearbox upwards, install the right propeller, and live with the possibly dangerous or funky flight handling of the airplane. > > Any other/better/wiser/workable ideas from the Kolb List are very very welcome! > > > Bill Berle > www.ezflaphandle.com - safety & performance upgrade for light aircraft > www.grantstar.net - winning proposals for non-profit and for-profit entities > > -------------------------------------------- > On Wed, 5/9/18, George Helton <gdhelton@gmail.com> wrote: > > Subject: Re: Kolb-List: Re: High Thrust Line Question > To: kolb-list@matronics.com > Date: Wednesday, May 9, 2018, 9:39 AM > > --> Kolb-List message posted by: George > Helton <gdhelton@gmail.com> > > Well Bill, thanks for bringing up the > topic. I replaced my little Rotax 377 with new low rpm Hirth > 2702 over the winter. I really hadn't measured the > distance between the prop hub and boom tube. You sparked my > interest so I stopped by my hanger this morning to check it > out. The Hirth uses a G50 gearbox with 2:29 to 1 ratio. > which translates to 2400 rpm prop speed @ the engine's > max. HP rpm of 5500rpm. > Anyway, it measures 35.5 inches. This > is on a Kolb original Firestar. I did have to move the > engine forward 2.625" to compensate for the extra weight > of the new gear box. I went with a 64" 3 blade Powerfin > prop set at 6.4 degrees of pitch. This setup gives me 3.5" > of clearance from the boom tube. Thanks for inspiring me to > check it out. I'm sure there is a good combination > of prop out there for an HKS. > George Helton > 1986 Firestar, FS100 > 14GDH > Mesick, Michigan > gdhelton@gmail.com > > Sent from my iPhone > >> On May 8, 2018, at 11:08 PM, Bill > Berle <victorbravo@sbcglobal.net> > wrote: >> >> --> Kolb-List message posted > by: Bill Berle <victorbravo@sbcglobal.net> >> >> Everybody THANK YOU for taking > time for this discussion. >> >> I spoke to the Kolb factory today > by phone, and went out to the local UL flying field to see > an HKS engine run. >> >> Duane and Bryan at Kolb were asked > one specific question by me: What is the maximum > number of inches allowable or advisable between the center > of the propeller and the top of the tailboom? >> >> Bryan said that 36 inches is about > standard for a "normal" Firestar, and he would not want to > fly an airplane with that distance raised to 39 or 40 > inches. >> >> I went back to my hangar and > measured, and the distance on my Firestar would be over 40 > or 41 inches if I turned the gearbox upward. So if the Kolb > factory owner says 40 inches is too high, I can only be > humble and assume that I wouldn't want to fly it at 40 > inches either. If any of the highly experienced Kolbers on > this forum are flying with their thrust line 40 inches above > the tailboom, I REALLY would like to know about it pronto. >> >> As big of an ego as I have had a > few times in my life, and as much as I think of myself as a > reasonably skilled pilot, I don't need to be a test > pilot here and try to push any envelope at this early stage. > So if I can ask the Kolb ilst a favor... if any of you are > flying a Firestar with the engine thrust line 39 or 40 or 41 > incvhes above the tailboom please post this on the list and > let me know ifyou have any issues with the handling, > pitch-over, etc. >> >> Bill Berle >> www.ezflaphandle.com - > safety & performance upgrade for light aircraft >> www.grantstar.net > - winning proposals for non-profit and > for-profit entities >> >> > -------------------------------------------- >> On Tue, 5/8/18, Richard Pike > <thegreybaron@charter.net> > wrote: >> >> Subject: Kolb-List: Re: High > Thrust Line Question >> To: kolb-list@matronics.com >> Date: Tuesday, May 8, 2018, 4:38 > PM >> >> --> Kolb-List message posted > by: "Richard >> Pike" <thegreybaron@charter.net> >> >> Bill; notice the extent to which > Rick >> raised his engine. (Great > pictures) Maybe you can leave the >> gearbox down and raise the engine > up? >> >> -------- >> Richard Pike >> Kolb MKIII N420P (420ldPoops) >> Kingsport, TN 3TN0 >> >> Forgiving is tough, being forgiven > is >> wonderful, and God's grace really > is amazing. >> >> >> >> >> Read this topic online here: >> >> http://forums.matronics.com/viewtopic.php?p=479963#479963 >> >> >> >> >> >> >> The Kolb-List Email Forum - >> Navigator to browse >> List Un/Subscription, >> 7-Day Browse, Chat, FAQ, >> - MATRONICS > WEB FORUMS - >> via the Web Forums! >> - NEW MATRONICS LIST > WIKI - >> Email List Wiki! >> - List Contribution > Web Site - >> support! >> > >> -Matt Dralle, List > Admin. >> >> >> >> >> >> >> >> > > The Kolb-List Email Forum - > Navigator to browse > List Un/Subscription, > 7-Day Browse, Chat, FAQ, > - MATRONICS WEB FORUMS - > via the Web Forums! > - NEW MATRONICS LIST WIKI - > Email List Wiki! > - List Contribution Web Site - > support! > > -Matt Dralle, List Admin. > > The Kolb-List Email Forum - Navigator to browse List Un/Subscription, 7-Day Browse, Chat, FAQ, - MATRONICS WEB FORUMS - via the Web Forums! - NEW MATRONICS LIST WIKI - Email List Wiki! - List Contribution Web Site - support! -Matt Dralle, List Admin.


    Message 12


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    Time: 03:29:52 PM PST US
    From: "Jack Hart" <jbhart@onlyinternet.net>
    Subject: Re: High Thrust Line Question
    Bill, If you are worried about the effects of a high thrust line, you may want t o consider adding some area to your horizontal stabilizer. This should red uce some of the increased stick forces and tail work load. Jack B. Hart FF004 Winchester, IN ---------------------------------------- From: "Bill Berle" <victorbravo@sbcglobal.net> Sent: Wednesday, May 9, 2018 3:58 PM Subject: Re: Kolb-List: Re: High Thrust Line Question The replacement gear set does not fit into the same gearbox case. So unfort unately I cannot just buy two new gears and slide them into place. BUT... I am making progress towards one of the other potential solutions. A fter consulting with an experienced aircraft structures and metallurgy engi neer, I believe I can make a simple prop extension that is held on with one central nut (a great big nut !) and remove the propeller before folding th e wings. The key to doing this SAFELY is called the Belleville Spring, or Belleville Washer. It is a conical spring steel washer that becomes flat (like a regu lar washer) as it is tightened, providing a known, reliable tension/compres sion force over a reasonable range of installation torques. This means that I can install the propeller, tighten the nut until the Bell eville Washer is more or less flat, and be confident that there is plenty o f tension/compression in the propeller mounting without having to use a tor que wrench, elaborate bolt stretch charts, etc. etc. This also provides a m uch more convenient and error-proof option instead of havign to torque six propeller bolts and safety wire the bolts, install six Cotter Pins, etc. All of this means I will be hopefully able to use a 4, 5, or 6 blade prop w ith the thrust line within Kolb's recommended distance from the tailboom. The only downside is that Kolbers around the world will never stop making f un of me for turning a simple airplane into a major engineering project :) The HKS engine is a VERY good quality engine and I believe the other Kolb/H KS owners will agree they love the engine. If you wish to use this engine o n a Kolb, don't hold my mis-adventures against the engine... just make darn sure you get the 2.58 gearbox ! Bill Berle www.ezflaphandle.com - safety & performance upgrade for light aircraft www.grantstar.net - winning proposals for non-profit and for-prof it entities -------------------------------------------- On Wed, 5/9/18, George Helton <gdhelton@gmail.com> wrote: Subject: Re: Kolb-List: Re: High Thrust Line Question Helton <gdhelton@gmail.com> Bill, I know that this might sound crazy but, can't you just buy a different set of gears for the gearbox? Being a mechanic may be a benefit here but I can't imagine that HKS can't supply replacement parts. The gearbox case doesn't care what gears fit inside of it. If they don't, I'd sure shy away from buying one. George Helton 1986 Firestar, FS100 14GDH Mesick, Michigan gdhelton@gmail.com Sent from my iPhone > On May 9, 2018, at 2:18 PM, Bill Berle <victorbravo@sbcglobal.net> wrote: > > --> Kolb-List message posted by: Bill Berle <victorbravo@sbcglobal.net> > > I have been pulling out what's left of my hair over this issue. I really don't want to quit, I LIKE the Kolb airframe and it will fit my mission well. I like the HKS fuel economy and improved reliability. I just wound up with the wrong gearbox on it and cannot afford to change it. > > What I have learned thus far is: > > 1) My 3.47 to 1 gearbox really wants to swing a larger propeller than what is actually "correct" for the height of the thrust line on the Kolb airframe. > > 2) Turning the gearbox upwards will solve the prop diameter problem, but it creates a thrust line that is higher than the Kolb factory thinks is advisable. > > 3) I could easily go to a 4 or 5 blade propeller, solves the gearbox AND thrust line problems, but that interferes with folding the wings. > > I have considered many possible solutions or "work-arounds" : > > 1) Get a 5 blade propeller and remove it after every flight, which would allow ALL of the problems to be solved, at the cost of additional time and effort every time I fly. This will cost the least of all the "solutions". > > 2) Remove the wings after every flight instead of folding the wings. This allows a 5 blade propeller to be used but adds complexity and requires me to build a complicated ground fixture to allow the wings to be removed and installed by myself alone. > > 3) Make a folding propeller, like the electric R/C model gliders have, where the blades fold rearward. This solves all of the problems, no complex ground equipment, but designing and manufacturing such a propeller will be prohibitvely expensive. > > 4) Buy another gearbox from HKS. This is the best solution mechanically, but I cannot afford it. > > 5) Turn the gearbox upwards, install the right propeller, and live with the possibly dangerous or funky flight handling of the airplane. > > Any other/better/wiser/workable ideas from the Kolb List are very very welcome! > > > Bill Berle > www.ezflaphandle.com - safety & performance upgrade for light aircraft > www.grantstar.net - winning proposals for non-profit and for-profit entities > > -------------------------------------------- > On Wed, 5/9/18, George Helton <gdhelton@gmail.com> wrote: > > Subject: Re: Kolb-List: Re: High Thrust Line Question > To: kolb-list@matronics.com > Date: Wednesday, May 9, 2018, 9:39 AM > > --> Kolb-List message posted by: George > Helton <gdhelton@gmail.com> > > Well Bill, thanks for bringing up the > topic. I replaced my little Rotax 377 with new low rpm Hirth > 2702 over the winter. I really hadn't measured the > distance between the prop hub and boom tube. You sparked my > interest so I stopped by my hanger this morning to check it > out. The Hirth uses a G50 gearbox with 2:29 to 1 ratio. > which translates to 2400 rpm prop speed @ the engine's > max. HP rpm of 5500rpm. > Anyway, it measures 35.5 inches. This > is on a Kolb original Firestar. I did have to move the > engine forward 2.625" to compensate for the extra weight > of the new gear box. I went with a 64" 3 blade Powerfin > prop set at 6.4 degrees of pitch. This setup gives me 3.5" > of clearance from the boom tube. Thanks for inspiring me to > check it out. I'm sure there is a good combination > of prop out there for an HKS. > George Helton > 1986 Firestar, FS100 > 14GDH > Mesick, Michigan > gdhelton@gmail.com > > Sent from my iPhone > >> On May 8, 2018, at 11:08 PM, Bill > Berle <victorbravo@sbcglobal.net> > wrote: >> >> --> Kolb-List message posted > by: Bill Berle <victorbravo@sbcglobal.net> >> >> Everybody THANK YOU for taking > time for this discussion. >> >> I spoke to the Kolb factory today > by phone, and went out to the local UL flying field to see > an HKS engine run. >> >> Duane and Bryan at Kolb were asked > one specific question by me: What is the maximum > number of inches allowable or advisable between the center > of the propeller and the top of the tailboom? >> >> Bryan said that 36 inches is about > standard for a "normal" Firestar, and he would not want to > fly an airplane with that distance raised to 39 or 40 > inches. >> >> I went back to my hangar and > measured, and the distance on my Firestar would be over 40 > or 41 inches if I turned the gearbox upward. So if the Kolb > factory owner says 40 inches is too high, I can only be > humble and assume that I wouldn't want to fly it at 40 > inches either. If any of the highly experienced Kolbers on > this forum are flying with their thrust line 40 inches above > the tailboom, I REALLY would like to know about it pronto. >> >> As big of an ego as I have had a > few times in my life, and as much as I think of myself as a > reasonably skilled pilot, I don't need to be a test > pilot here and try to push any envelope at this early stage. > So if I can ask the Kolb ilst a favor... if any of you are > flying a Firestar with the engine thrust line 39 or 40 or 41 > incvhes above the tailboom please post this on the list and > let me know ifyou have any issues with the handling, > pitch-over, etc. >> >> Bill Berle >> www.ezflaphandle.com - > safety & performance upgrade for light aircraft >> www.grantstar.net > - winning proposals for non-profit and > for-profit entities >> >> > -------------------------------------------- >> On Tue, 5/8/18, Richard Pike > <thegreybaron@charter.net> > wrote: >> >> Subject: Kolb-List: Re: High > Thrust Line Question >> To: kolb-list@matronics.com >> Date: Tuesday, May 8, 2018, 4:38 > PM >> >> --> Kolb-List message posted > by: "Richard >> Pike" <thegreybaron@charter.net> >> >> Bill; notice the extent to which > Rick >> raised his engine. (Great > pictures) Maybe you can leave the >> gearbox down and raise the engine > up? >> >> -------- >> Richard Pike >> Kolb MKIII N420P (420ldPoops) >> Kingsport, TN 3TN0 >> >> Forgiving is tough, being forgiven > is >> wonderful, and God's grace really > is amazing. >> >> >> >> >> Read this topic online here: >> >> http://forums.matronics.com/viewtopic.php?p=479963#479963 >> >> >> >> >> >> >> The Kolb-List Email Forum - >> Navigator to browse >> List Un/Subscription, >> 7-Day Browse, Chat, FAQ, >> - MATRONICS > WEB FORUMS - >> via the Web Forums! >> - NEW MATRONICS LIST > WIKI - >> Email List Wiki! >> - List Contribution > Web Site - >> support! >> > >> -Matt Dralle, List > Admin. >> >> >> >> >> >> >> >> > > The Kolb-List Email Forum - > Navigator to browse > List Un/Subscription, > 7-Day Browse, Chat, FAQ, > - MATRONICS WEB FORUMS - > via the Web Forums! > - NEW MATRONICS LIST WIKI - > Email List Wiki! > - List Contribution Web Site - > support! > > -Matt Dralle, List Admin. > > The Kolb-List Email Forum - Navigator to browse List Un/Subscription, 7-Day Browse, Chat, FAQ, - MATRONICS WEB FORUMS - via the Web Forums! - NEW MATRONICS LIST WIKI - Email List Wiki! - List Contribution Web Site - support! -Matt Dralle, List Admin.


    Message 13


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    Time: 04:21:53 PM PST US
    From: "John Hauck" <jhauck@elmore.rr.com>
    Subject: Re: High Thrust Line Question
    A large Belleville washer is used in the slip clutches in the 912 series gear boxes. john h mkIII Titus, Alabama -----Original Message----- From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] On Behalf Of George Helton Sent: Wednesday, May 09, 2018 4:09 PM Subject: Re: Kolb-List: Re: High Thrust Line Question I agree with you that the HKS is great engine. I considered it when I was shopping for a new engine for my original Firestar. But, after talking to Bryan at Kolb it wasnt to be. He didnt think the original Firestars had a strong enough cage assembly ( chromoly steel tubing wall thicknesses)to handle the torque that the HKS produces. I went along with his opinion. We used Belleville washers for many years in heavy equipment powershift transmissions as an alternative to the piston return springs inside the hydraulic clutch packs They worked great. They would fail eventually like anything else. But, it took ten of thousands of cycles. Good luck on the idea. George Helton 1986 Firestar, FS100 14GDH Mesick, Michigan gdhelton@gmail.com Sent from my iPhone > On May 9, 2018, at 3:54 PM, Bill Berle <victorbravo@sbcglobal.net> wrote: > > > The replacement gear set does not fit into the same gearbox case. So unfortunately I cannot just buy two new gears and slide them into place. > > BUT... I am making progress towards one of the other potential solutions. After consulting with an experienced aircraft structures and metallurgy engineer, I believe I can make a simple prop extension that is held on with one central nut (a great big nut !) and remove the propeller before folding the wings. > > The key to doing this SAFELY is called the Belleville Spring, or Belleville Washer. It is a conical spring steel washer that becomes flat (like a regular washer) as it is tightened, providing a known, reliable tension/compression force over a reasonable range of installation torques. > > This means that I can install the propeller, tighten the nut until the Belleville Washer is more or less flat, and be confident that there is plenty of tension/compression in the propeller mounting without having to use a torque wrench, elaborate bolt stretch charts, etc. etc. This also provides a much more convenient and error-proof option instead of havign to torque six propeller bolts and safety wire the bolts, install six Cotter Pins, etc. > > All of this means I will be hopefully able to use a 4, 5, or 6 blade prop with the thrust line within Kolb's recommended distance from the tailboom. > > The only downside is that Kolbers around the world will never stop making fun of me for turning a simple airplane into a major engineering project :) > > The HKS engine is a VERY good quality engine and I believe the other Kolb/HKS owners will agree they love the engine. If you wish to use this engine on a Kolb, don't hold my mis-adventures against the engine... just make darn sure you get the 2.58 gearbox ! > > Bill Berle > www.ezflaphandle.com - safety & performance upgrade for light aircraft > www.grantstar.net - winning proposals for non-profit and for-profit entities > > -------------------------------------------- > On Wed, 5/9/18, George Helton <gdhelton@gmail.com> wrote: > > Subject: Re: Kolb-List: Re: High Thrust Line Question > To: kolb-list@matronics.com > Date: Wednesday, May 9, 2018, 11:37 AM > > Helton <gdhelton@gmail.com> > > Bill, I know that this might sound > crazy but, cant you just buy a different set of gears for > the gearbox? Being a mechanic may be a benefit here but I > cant imagine that HKS cant supply replacement parts. > The gearbox case doesnt care what gears fit inside of it. > > If they dont, Id sure shy away > from buying one. > George Helton > 1986 Firestar, FS100 > 14GDH > Mesick, Michigan > gdhelton@gmail.com > > Sent from my iPhone > >> On May 9, 2018, at 2:18 PM, Bill > Berle <victorbravo@sbcglobal.net> > wrote: >> >> --> Kolb-List message posted > by: Bill Berle <victorbravo@sbcglobal.net> >> >> I have been pulling out what's > left of my hair over this issue. I really don't want to > quit, I LIKE the Kolb airframe and it will fit my mission > well. I like the HKS fuel economy and improved reliability. > I just wound up with the wrong gearbox on it and cannot > afford to change it. >> >> What I have learned thus far is: >> >> 1) My 3.47 to 1 gearbox really > wants to swing a larger propeller than what is > actually "correct" for the height of the thrust line > on the Kolb airframe. >> >> 2) Turning the gearbox upwards > will solve the prop diameter problem, but it creates a > thrust line that is higher than the Kolb factory thinks is > advisable. >> >> 3) I could easily go to a 4 or 5 > blade propeller, solves the gearbox AND thrust line > problems, but that interferes with folding the wings. >> >> I have considered many possible > solutions or "work-arounds" : >> >> 1) Get a 5 blade propeller and > remove it after every flight, which would allow ALL of the > problems to be solved, at the cost of additional time and > effort every time I fly. This will cost the least of all the > "solutions". >> >> 2) Remove the wings after every > flight instead of folding the wings. This allows a 5 blade > propeller to be used but adds complexity and requires me to > build a complicated ground fixture to allow the wings to be > removed and installed by myself alone. >> >> 3) Make a folding propeller, like > the electric R/C model gliders have, where the blades fold > rearward. This solves all of the problems, no complex ground > equipment, but designing and manufacturing such a propeller > will be prohibitvely expensive. >> >> 4) Buy another gearbox from HKS. > This is the best solution mechanically, but I cannot afford > it. >> >> 5) Turn the gearbox upwards, > install the right propeller, and live with the possibly > dangerous or funky flight handling of the airplane. >> >> Any other/better/wiser/workable > ideas from the Kolb List are very very welcome! >> >> >> >> >> Bill Berle >> www.ezflaphandle.com - > safety & performance upgrade for light aircraft >> www.grantstar.net > - winning proposals for non-profit and > for-profit entities >> >> > -------------------------------------------- >> On Wed, 5/9/18, George Helton > <gdhelton@gmail.com> > wrote: >> >> Subject: Re: Kolb-List: Re: High > Thrust Line Question >> To: kolb-list@matronics.com >> Date: Wednesday, May 9, 2018, 9:39 > AM >> >> --> Kolb-List message posted > by: George >> Helton <gdhelton@gmail.com> >> >> Well Bill, thanks for bringing up > the >> topic. I replaced my little Rotax > 377 with new low rpm Hirth >> 2702 over the winter. I really > hadnt measured the >> distance between the prop hub and > boom tube. You sparked my >> interest so I stopped by my hanger > this morning to check it >> out. The Hirth uses a G50 gearbox > with 2:29 to 1 ratio. >> which translates to 2400 rpm prop > speed @ the engines >> max. HP rpm of 5500rpm. >> Anyway, it measures 35.5 inches. > This >> is on a Kolb original Firestar. I > did have to move the >> engine forward 2.625 to > compensate for the extra weight >> of the new gear box. I went with a > 64 3 blade Powerfin >> prop set at 6.4 degrees of pitch. > This setup gives me 3.5 >> of clearance from the boom tube. > Thanks for inspiring me to >> check it out. Im sure > there is a good combination >> of prop out there for an HKS. >> George Helton >> 1986 Firestar, FS100 >> 14GDH >> Mesick, Michigan >> gdhelton@gmail.com >> >> Sent from my iPhone >> >>> On May 8, 2018, at 11:08 PM, > Bill >> Berle <victorbravo@sbcglobal.net> >> wrote: >>> >>> --> Kolb-List message > posted >> by: Bill Berle <victorbravo@sbcglobal.net> >>> >>> Everybody THANK YOU for > taking >> time for this discussion. >>> >>> I spoke to the Kolb factory > today >> by phone, and went out to the > local UL flying field to see >> an HKS engine run. >>> >>> Duane and Bryan at Kolb were > asked >> one specific question by me: > What is the maximum >> number of inches allowable or > advisable between the center >> of the propeller and the top of > the tailboom? >>> >>> Bryan said that 36 inches is > about >> standard for a "normal" Firestar, > and he would not want to >> fly an airplane with that distance > raised to 39 or 40 >> inches. >>> >>> I went back to my hangar and >> measured, and the distance on my > Firestar would be over 40 >> or 41 inches if I turned the > gearbox upward. So if the Kolb >> factory owner says 40 inches is > too high, I can only be >> humble and assume that I wouldn't > want to fly it at 40 >> inches either. If any of the > highly experienced Kolbers on >> this forum are flying with their > thrust line 40 inches above >> the tailboom, I REALLY would like > to know about it pronto. >>> >>> As big of an ego as I have had > a >> few times in my life, and as much > as I think of myself as a >> reasonably skilled pilot, I > don't need to be a test >> pilot here and try to push any > envelope at this early stage. >> So if I can ask the Kolb ilst a > favor... if any of you are >> flying a Firestar with the engine > thrust line 39 or 40 or 41 >> incvhes above the tailboom please > post this on the list and >> let me know ifyou have any issues > with the handling, >> pitch-over, etc. >>> >>> Bill Berle >>> www.ezflaphandle.com - >> safety & performance upgrade > for light aircraft >>> www.grantstar.net >> - > winning proposals for non-profit and >> for-profit entities >>> >>> >> > -------------------------------------------- >>> On Tue, 5/8/18, Richard Pike >> <thegreybaron@charter.net> >> wrote: >>> >>> Subject: Kolb-List: Re: High >> Thrust Line Question >>> To: kolb-list@matronics.com >>> Date: Tuesday, May 8, 2018, > 4:38 >> PM >>> >>> --> Kolb-List message > posted >> by: "Richard >>> Pike" <thegreybaron@charter.net> >>> >>> Bill; notice the extent to > which >> Rick >>> raised his engine. (Great >> pictures) Maybe you can leave the >>> gearbox down and raise the > engine >> up? >>> >>> -------- >>> Richard Pike >>> Kolb MKIII N420P (420ldPoops) >>> Kingsport, TN 3TN0 >>> >>> Forgiving is tough, being > forgiven >> is >>> wonderful, and God's grace > really >> is amazing. >>> >>> >>> >>> >>> Read this topic online here: >>> >>> http://forums.matronics.com/viewtopic.php?p=479963#479963 >>> >>> >>> >>> >>> >>> >>> The Kolb-List Email Forum - >>> Navigator to browse >>> List Un/Subscription, >>> 7-Day Browse, Chat, FAQ, >>> - > MATRONICS >> WEB FORUMS - >>> via the Web Forums! >>> - NEW > MATRONICS LIST >> WIKI - >>> Email List Wiki! >>> - List > Contribution >> Web Site - >>> support! >>> > >> >>> -Matt > Dralle, List >> Admin. >>> >>> >>> >>> >>> >>> >>> >>> >> >> The Kolb-List Email Forum - >> Navigator to browse >> List Un/Subscription, >> 7-Day Browse, Chat, FAQ, >> - MATRONICS > WEB FORUMS - >> via the Web Forums! >> - NEW MATRONICS LIST > WIKI - >> Email List Wiki! >> - List Contribution > Web Site - >> support! >> > >> -Matt Dralle, List > Admin. >> >> >> >> >> >> >> >> > > The Kolb-List Email Forum - > Navigator to browse > List Un/Subscription, > 7-Day Browse, Chat, FAQ, > - MATRONICS WEB FORUMS - > via the Web Forums! > - NEW MATRONICS LIST WIKI - > Email List Wiki! > - List Contribution Web Site - > support! > > -Matt Dralle, List Admin. > > > > > > > >


    Message 14


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    Time: 05:00:55 PM PST US
    From: "Jack Hart" <jbhart@onlyinternet.net>
    Subject: Re: High Thrust Line Question
    Bill, If you are worried about the effects of a high thrust line, you may want t o consider adding some area to your horizontal stabilizer. This should red uce some of the increased stick forces and tail work load. Jack B. Hart FF004 Winchester, IN ---------------------------------------- From: "Bill Berle" <victorbravo@sbcglobal.net> Sent: Wednesday, May 9, 2018 3:58 PM Subject: Re: Kolb-List: Re: High Thrust Line Question The replacement gear set does not fit into the same gearbox case. So unfort unately I cannot just buy two new gears and slide them into place. BUT... I am making progress towards one of the other potential solutions. A fter consulting with an experienced aircraft structures and metallurgy engi neer, I believe I can make a simple prop extension that is held on with one central nut (a great big nut !) and remove the propeller before folding th e wings. The key to doing this SAFELY is called the Belleville Spring, or Belleville Washer. It is a conical spring steel washer that becomes flat (like a regu lar washer) as it is tightened, providing a known, reliable tension/compres sion force over a reasonable range of installation torques. This means that I can install the propeller, tighten the nut until the Bell eville Washer is more or less flat, and be confident that there is plenty o f tension/compression in the propeller mounting without having to use a tor que wrench, elaborate bolt stretch charts, etc. etc. This also provides a m uch more convenient and error-proof option instead of havign to torque six propeller bolts and safety wire the bolts, install six Cotter Pins, etc. All of this means I will be hopefully able to use a 4, 5, or 6 blade prop w ith the thrust line within Kolb's recommended distance from the tailboom. The only downside is that Kolbers around the world will never stop making f un of me for turning a simple airplane into a major engineering project :) The HKS engine is a VERY good quality engine and I believe the other Kolb/H KS owners will agree they love the engine. If you wish to use this engine o n a Kolb, don't hold my mis-adventures against the engine... just make darn sure you get the 2.58 gearbox ! Bill Berle www.ezflaphandle.com - safety & performance upgrade for light aircraft www.grantstar.net - winning proposals for non-profit and for-prof it entities -------------------------------------------- On Wed, 5/9/18, George Helton <gdhelton@gmail.com> wrote: Subject: Re: Kolb-List: Re: High Thrust Line Question Helton <gdhelton@gmail.com> Bill, I know that this might sound crazy but, can't you just buy a different set of gears for the gearbox? Being a mechanic may be a benefit here but I can't imagine that HKS can't supply replacement parts. The gearbox case doesn't care what gears fit inside of it. If they don't, I'd sure shy away from buying one. George Helton 1986 Firestar, FS100 14GDH Mesick, Michigan gdhelton@gmail.com Sent from my iPhone > On May 9, 2018, at 2:18 PM, Bill Berle <victorbravo@sbcglobal.net> wrote: > > --> Kolb-List message posted by: Bill Berle <victorbravo@sbcglobal.net> > > I have been pulling out what's left of my hair over this issue. I really don't want to quit, I LIKE the Kolb airframe and it will fit my mission well. I like the HKS fuel economy and improved reliability. I just wound up with the wrong gearbox on it and cannot afford to change it. > > What I have learned thus far is: > > 1) My 3.47 to 1 gearbox really wants to swing a larger propeller than what is actually "correct" for the height of the thrust line on the Kolb airframe. > > 2) Turning the gearbox upwards will solve the prop diameter problem, but it creates a thrust line that is higher than the Kolb factory thinks is advisable. > > 3) I could easily go to a 4 or 5 blade propeller, solves the gearbox AND thrust line problems, but that interferes with folding the wings. > > I have considered many possible solutions or "work-arounds" : > > 1) Get a 5 blade propeller and remove it after every flight, which would allow ALL of the problems to be solved, at the cost of additional time and effort every time I fly. This will cost the least of all the "solutions". > > 2) Remove the wings after every flight instead of folding the wings. This allows a 5 blade propeller to be used but adds complexity and requires me to build a complicated ground fixture to allow the wings to be removed and installed by myself alone. > > 3) Make a folding propeller, like the electric R/C model gliders have, where the blades fold rearward. This solves all of the problems, no complex ground equipment, but designing and manufacturing such a propeller will be prohibitvely expensive. > > 4) Buy another gearbox from HKS. This is the best solution mechanically, but I cannot afford it. > > 5) Turn the gearbox upwards, install the right propeller, and live with the possibly dangerous or funky flight handling of the airplane. > > Any other/better/wiser/workable ideas from the Kolb List are very very welcome! > > > Bill Berle > www.ezflaphandle.com - safety & performance upgrade for light aircraft > www.grantstar.net - winning proposals for non-profit and for-profit entities > > -------------------------------------------- > On Wed, 5/9/18, George Helton <gdhelton@gmail.com> wrote: > > Subject: Re: Kolb-List: Re: High Thrust Line Question > To: kolb-list@matronics.com > Date: Wednesday, May 9, 2018, 9:39 AM > > --> Kolb-List message posted by: George > Helton <gdhelton@gmail.com> > > Well Bill, thanks for bringing up the > topic. I replaced my little Rotax 377 with new low rpm Hirth > 2702 over the winter. I really hadn't measured the > distance between the prop hub and boom tube. You sparked my > interest so I stopped by my hanger this morning to check it > out. The Hirth uses a G50 gearbox with 2:29 to 1 ratio. > which translates to 2400 rpm prop speed @ the engine's > max. HP rpm of 5500rpm. > Anyway, it measures 35.5 inches. This > is on a Kolb original Firestar. I did have to move the > engine forward 2.625" to compensate for the extra weight > of the new gear box. I went with a 64" 3 blade Powerfin > prop set at 6.4 degrees of pitch. This setup gives me 3.5" > of clearance from the boom tube. Thanks for inspiring me to > check it out. I'm sure there is a good combination > of prop out there for an HKS. > George Helton > 1986 Firestar, FS100 > 14GDH > Mesick, Michigan > gdhelton@gmail.com > > Sent from my iPhone > >> On May 8, 2018, at 11:08 PM, Bill > Berle <victorbravo@sbcglobal.net> > wrote: >> >> --> Kolb-List message posted > by: Bill Berle <victorbravo@sbcglobal.net> >> >> Everybody THANK YOU for taking > time for this discussion. >> >> I spoke to the Kolb factory today > by phone, and went out to the local UL flying field to see > an HKS engine run. >> >> Duane and Bryan at Kolb were asked > one specific question by me: What is the maximum > number of inches allowable or advisable between the center > of the propeller and the top of the tailboom? >> >> Bryan said that 36 inches is about > standard for a "normal" Firestar, and he would not want to > fly an airplane with that distance raised to 39 or 40 > inches. >> >> I went back to my hangar and > measured, and the distance on my Firestar would be over 40 > or 41 inches if I turned the gearbox upward. So if the Kolb > factory owner says 40 inches is too high, I can only be > humble and assume that I wouldn't want to fly it at 40 > inches either. If any of the highly experienced Kolbers on > this forum are flying with their thrust line 40 inches above > the tailboom, I REALLY would like to know about it pronto. >> >> As big of an ego as I have had a > few times in my life, and as much as I think of myself as a > reasonably skilled pilot, I don't need to be a test > pilot here and try to push any envelope at this early stage. > So if I can ask the Kolb ilst a favor... if any of you are > flying a Firestar with the engine thrust line 39 or 40 or 41 > incvhes above the tailboom please post this on the list and > let me know ifyou have any issues with the handling, > pitch-over, etc. >> >> Bill Berle >> www.ezflaphandle.com - > safety & performance upgrade for light aircraft >> www.grantstar.net > - winning proposals for non-profit and > for-profit entities >> >> > -------------------------------------------- >> On Tue, 5/8/18, Richard Pike > <thegreybaron@charter.net> > wrote: >> >> Subject: Kolb-List: Re: High > Thrust Line Question >> To: kolb-list@matronics.com >> Date: Tuesday, May 8, 2018, 4:38 > PM >> >> --> Kolb-List message posted > by: "Richard >> Pike" <thegreybaron@charter.net> >> >> Bill; notice the extent to which > Rick >> raised his engine. (Great > pictures) Maybe you can leave the >> gearbox down and raise the engine > up? >> >> -------- >> Richard Pike >> Kolb MKIII N420P (420ldPoops) >> Kingsport, TN 3TN0 >> >> Forgiving is tough, being forgiven > is >> wonderful, and God's grace really > is amazing. >> >> >> >> >> Read this topic online here: >> >> http://forums.matronics.com/viewtopic.php?p=479963#479963 >> >> >> >> >> >> >> The Kolb-List Email Forum - >> Navigator to browse >> List Un/Subscription, >> 7-Day Browse, Chat, FAQ, >> - MATRONICS > WEB FORUMS - >> via the Web Forums! >> - NEW MATRONICS LIST > WIKI - >> Email List Wiki! >> - List Contribution > Web Site - >> support! >> > >> -Matt Dralle, List > Admin. >> >> >> >> >> >> >> >> > > The Kolb-List Email Forum - > Navigator to browse > List Un/Subscription, > 7-Day Browse, Chat, FAQ, > - MATRONICS WEB FORUMS - > via the Web Forums! > - NEW MATRONICS LIST WIKI - > Email List Wiki! > - List Contribution Web Site - > support! > > -Matt Dralle, List Admin. > > The Kolb-List Email Forum - Navigator to browse List Un/Subscription, 7-Day Browse, Chat, FAQ, - MATRONICS WEB FORUMS - via the Web Forums! - NEW MATRONICS LIST WIKI - Email List Wiki! - List Contribution Web Site - support! -Matt Dralle, List Admin.


    Message 15


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    Time: 05:31:19 PM PST US
    From: George Helton <gdhelton@gmail.com>
    Subject: Re: High Thrust Line Question
    Youre right John. Actually Rotax has used them in their gearboxes for years in smaller version. They stacked them face to face in the anti-clatter mechanisms. George Helton 1986 Firestar, FS100 14GDH Mesick, Michigan gdhelton@gmail.com Sent from my iPhone > On May 9, 2018, at 7:20 PM, John Hauck <jhauck@elmore.rr.com> wrote: > > > A large Belleville washer is used in the slip clutches in the 912 series gear boxes. > > john h > mkIII > Titus, Alabama > > > > > -----Original Message----- > From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] On Behalf Of George Helton > Sent: Wednesday, May 09, 2018 4:09 PM > To: kolb-list@matronics.com > Subject: Re: Kolb-List: Re: High Thrust Line Question > > > I agree with you that the HKS is great engine. I considered it when I was shopping for a new engine for my original Firestar. But, after talking to Bryan at Kolb it wasnt to be. He didnt think the original Firestars had a strong enough cage assembly ( chromoly steel tubing wall thicknesses)to handle the torque that the HKS produces. I > went along with his opinion. > We used Belleville washers for many years in heavy equipment powershift transmissions as an alternative to the piston return springs inside the hydraulic clutch packs They worked great. They would fail eventually like anything else. But, it took ten of thousands of cycles. Good luck on the idea. > > George Helton > 1986 Firestar, FS100 > 14GDH > Mesick, Michigan > gdhelton@gmail.com > > Sent from my iPhone > >> On May 9, 2018, at 3:54 PM, Bill Berle <victorbravo@sbcglobal.net> wrote: >> >> >> The replacement gear set does not fit into the same gearbox case. So unfortunately I cannot just buy two new gears and slide them into place. >> >> BUT... I am making progress towards one of the other potential solutions. After consulting with an experienced aircraft structures and metallurgy engineer, I believe I can make a simple prop extension that is held on with one central nut (a great big nut !) and remove the propeller before folding the wings. >> >> The key to doing this SAFELY is called the Belleville Spring, or Belleville Washer. It is a conical spring steel washer that becomes flat (like a regular washer) as it is tightened, providing a known, reliable tension/compression force over a reasonable range of installation torques. >> >> This means that I can install the propeller, tighten the nut until the Belleville Washer is more or less flat, and be confident that there is plenty of tension/compression in the propeller mounting without having to use a torque wrench, elaborate bolt stretch charts, etc. etc. This also provides a much more convenient and error-proof option instead of havign to torque six propeller bolts and safety wire the bolts, install six Cotter Pins, etc. >> >> All of this means I will be hopefully able to use a 4, 5, or 6 blade prop with the thrust line within Kolb's recommended distance from the tailboom. >> >> The only downside is that Kolbers around the world will never stop making fun of me for turning a simple airplane into a major engineering project :) >> >> The HKS engine is a VERY good quality engine and I believe the other Kolb/HKS owners will agree they love the engine. If you wish to use this engine on a Kolb, don't hold my mis-adventures against the engine... just make darn sure you get the 2.58 gearbox ! >> >> Bill Berle >> www.ezflaphandle.com - safety & performance upgrade for light aircraft >> www.grantstar.net - winning proposals for non-profit and for-profit entities >> >> -------------------------------------------- >> On Wed, 5/9/18, George Helton <gdhelton@gmail.com> wrote: >> >> Subject: Re: Kolb-List: Re: High Thrust Line Question >> To: kolb-list@matronics.com >> Date: Wednesday, May 9, 2018, 11:37 AM >> >> Helton <gdhelton@gmail.com> >> >> Bill, I know that this might sound >> crazy but, cant you just buy a different set of gears for >> the gearbox? Being a mechanic may be a benefit here but I >> cant imagine that HKS cant supply replacement parts. >> The gearbox case doesnt care what gears fit inside of it. >> >> If they dont, Id sure shy away >> from buying one. >> George Helton >> 1986 Firestar, FS100 >> 14GDH >> Mesick, Michigan >> gdhelton@gmail.com >> >> Sent from my iPhone >> >>> On May 9, 2018, at 2:18 PM, Bill >> Berle <victorbravo@sbcglobal.net> >> wrote: >>> >>> --> Kolb-List message posted >> by: Bill Berle <victorbravo@sbcglobal.net> >>> >>> I have been pulling out what's >> left of my hair over this issue. I really don't want to >> quit, I LIKE the Kolb airframe and it will fit my mission >> well. I like the HKS fuel economy and improved reliability. >> I just wound up with the wrong gearbox on it and cannot >> afford to change it. >>> >>> What I have learned thus far is: >>> >>> 1) My 3.47 to 1 gearbox really >> wants to swing a larger propeller than what is >> actually "correct" for the height of the thrust line >> on the Kolb airframe. >>> >>> 2) Turning the gearbox upwards >> will solve the prop diameter problem, but it creates a >> thrust line that is higher than the Kolb factory thinks is >> advisable. >>> >>> 3) I could easily go to a 4 or 5 >> blade propeller, solves the gearbox AND thrust line >> problems, but that interferes with folding the wings. >>> >>> I have considered many possible >> solutions or "work-arounds" : >>> >>> 1) Get a 5 blade propeller and >> remove it after every flight, which would allow ALL of the >> problems to be solved, at the cost of additional time and >> effort every time I fly. This will cost the least of all the >> "solutions". >>> >>> 2) Remove the wings after every >> flight instead of folding the wings. This allows a 5 blade >> propeller to be used but adds complexity and requires me to >> build a complicated ground fixture to allow the wings to be >> removed and installed by myself alone. >>> >>> 3) Make a folding propeller, like >> the electric R/C model gliders have, where the blades fold >> rearward. This solves all of the problems, no complex ground >> equipment, but designing and manufacturing such a propeller >> will be prohibitvely expensive. >>> >>> 4) Buy another gearbox from HKS. >> This is the best solution mechanically, but I cannot afford >> it. >>> >>> 5) Turn the gearbox upwards, >> install the right propeller, and live with the possibly >> dangerous or funky flight handling of the airplane. >>> >>> Any other/better/wiser/workable >> ideas from the Kolb List are very very welcome! >>> >>> >>> >>> >>> Bill Berle >>> www.ezflaphandle.com - >> safety & performance upgrade for light aircraft >>> www.grantstar.net >> - winning proposals for non-profit and >> for-profit entities >>> >>> >> -------------------------------------------- >>> On Wed, 5/9/18, George Helton >> <gdhelton@gmail.com> >> wrote: >>> >>> Subject: Re: Kolb-List: Re: High >> Thrust Line Question >>> To: kolb-list@matronics.com >>> Date: Wednesday, May 9, 2018, 9:39 >> AM >>> >>> --> Kolb-List message posted >> by: George >>> Helton <gdhelton@gmail.com> >>> >>> Well Bill, thanks for bringing up >> the >>> topic. I replaced my little Rotax >> 377 with new low rpm Hirth >>> 2702 over the winter. I really >> hadnt measured the >>> distance between the prop hub and >> boom tube. You sparked my >>> interest so I stopped by my hanger >> this morning to check it >>> out. The Hirth uses a G50 gearbox >> with 2:29 to 1 ratio. >>> which translates to 2400 rpm prop >> speed @ the engines >>> max. HP rpm of 5500rpm. >>> Anyway, it measures 35.5 inches. >> This >>> is on a Kolb original Firestar. I >> did have to move the >>> engine forward 2.625 to >> compensate for the extra weight >>> of the new gear box. I went with a >> 64 3 blade Powerfin >>> prop set at 6.4 degrees of pitch. >> This setup gives me 3.5 >>> of clearance from the boom tube. >> Thanks for inspiring me to >>> check it out. Im sure >> there is a good combination >>> of prop out there for an HKS. >>> George Helton >>> 1986 Firestar, FS100 >>> 14GDH >>> Mesick, Michigan >>> gdhelton@gmail.com >>> >>> Sent from my iPhone >>> >>>> On May 8, 2018, at 11:08 PM, >> Bill >>> Berle <victorbravo@sbcglobal.net> >>> wrote: >>>> >>>> --> Kolb-List message >> posted >>> by: Bill Berle <victorbravo@sbcglobal.net> >>>> >>>> Everybody THANK YOU for >> taking >>> time for this discussion. >>>> >>>> I spoke to the Kolb factory >> today >>> by phone, and went out to the >> local UL flying field to see >>> an HKS engine run. >>>> >>>> Duane and Bryan at Kolb were >> asked >>> one specific question by me: >> What is the maximum >>> number of inches allowable or >> advisable between the center >>> of the propeller and the top of >> the tailboom? >>>> >>>> Bryan said that 36 inches is >> about >>> standard for a "normal" Firestar, >> and he would not want to >>> fly an airplane with that distance >> raised to 39 or 40 >>> inches. >>>> >>>> I went back to my hangar and >>> measured, and the distance on my >> Firestar would be over 40 >>> or 41 inches if I turned the >> gearbox upward. So if the Kolb >>> factory owner says 40 inches is >> too high, I can only be >>> humble and assume that I wouldn't >> want to fly it at 40 >>> inches either. If any of the >> highly experienced Kolbers on >>> this forum are flying with their >> thrust line 40 inches above >>> the tailboom, I REALLY would like >> to know about it pronto. >>>> >>>> As big of an ego as I have had >> a >>> few times in my life, and as much >> as I think of myself as a >>> reasonably skilled pilot, I >> don't need to be a test >>> pilot here and try to push any >> envelope at this early stage. >>> So if I can ask the Kolb ilst a >> favor... if any of you are >>> flying a Firestar with the engine >> thrust line 39 or 40 or 41 >>> incvhes above the tailboom please >> post this on the list and >>> let me know ifyou have any issues >> with the handling, >>> pitch-over, etc. >>>> >>>> Bill Berle >>>> www.ezflaphandle.com - >>> safety & performance upgrade >> for light aircraft >>>> www.grantstar.net >>> - >> winning proposals for non-profit and >>> for-profit entities >>>> >>>> >>> >> -------------------------------------------- >>>> On Tue, 5/8/18, Richard Pike >>> <thegreybaron@charter.net> >>> wrote: >>>> >>>> Subject: Kolb-List: Re: High >>> Thrust Line Question >>>> To: kolb-list@matronics.com >>>> Date: Tuesday, May 8, 2018, >> 4:38 >>> PM >>>> >>>> --> Kolb-List message >> posted >>> by: "Richard >>>> Pike" <thegreybaron@charter.net> >>>> >>>> Bill; notice the extent to >> which >>> Rick >>>> raised his engine. (Great >>> pictures) Maybe you can leave the >>>> gearbox down and raise the >> engine >>> up? >>>> >>>> -------- >>>> Richard Pike >>>> Kolb MKIII N420P (420ldPoops) >>>> Kingsport, TN 3TN0 >>>> >>>> Forgiving is tough, being >> forgiven >>> is >>>> wonderful, and God's grace >> really >>> is amazing. >>>> >>>> >>>> >>>> >>>> Read this topic online here: >>>> >>>> http://forums.matronics.com/viewtopic.php?p=479963#479963 >>>> >>>> >>>> >>>> >>>> >>>> >>>> The Kolb-List Email Forum - >>>> Navigator to browse >>>> List Un/Subscription, >>>> 7-Day Browse, Chat, FAQ, >>>> - >> MATRONICS >>> WEB FORUMS - >>>> via the Web Forums! >>>> - NEW >> MATRONICS LIST >>> WIKI - >>>> Email List Wiki! >>>> - List >> Contribution >>> Web Site - >>>> support! >>>> >> >>> >>>> -Matt >> Dralle, List >>> Admin. >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>>> >>> >>> The Kolb-List Email Forum - >>> Navigator to browse >>> List Un/Subscription, >>> 7-Day Browse, Chat, FAQ, >>> - MATRONICS >> WEB FORUMS - >>> via the Web Forums! >>> - NEW MATRONICS LIST >> WIKI - >>> Email List Wiki! >>> - List Contribution >> Web Site - >>> support! >>> >> >>> -Matt Dralle, List >> Admin. >>> >>> >>> >>> >>> >>> >>> >>> >> >> The Kolb-List Email Forum - >> Navigator to browse >> List Un/Subscription, >> 7-Day Browse, Chat, FAQ, >> - MATRONICS WEB FORUMS - >> via the Web Forums! >> - NEW MATRONICS LIST WIKI - >> Email List Wiki! >> - List Contribution Web Site - >> support! >> >> -Matt Dralle, List Admin. >> >> >> >> >> >> >> >> > > > > > > > >




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