---------------------------------------------------------- Kolb-List Digest Archive --- Total Messages Posted Tue 10/21/03: 20 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:28 AM - Bob Brocious, are you out there? () 2. 08:20 AM - Re: Engine Cowling (Gherkins Tim-rp3420) 3. 08:58 AM - Re: Wings (Richard & Martha Neilsen) 4. 09:17 AM - Re: Engine Cowling (Richard & Martha Neilsen) 5. 10:15 AM - Engine Cowling (James, Ken) 6. 10:38 AM - [ Audrey Lewis ] : New Email List Photo Share Available! (Email List Photo Shares) 7. 10:44 AM - axle spacers (ul15rhb@juno.com) 8. 12:18 PM - Re: Wings (Jack & Louise Hart) 9. 02:25 PM - Re: Vortex Generators update - success! (HShack@aol.com) 10. 04:01 PM - Re: axle spacers (BKlebon@aol.com) 11. 04:28 PM - Re: Vortex Generators update - success! (Richard Pike) 12. 04:33 PM - building (Paul Petty) 13. 04:45 PM - Re: Vortex Generators update - success! (Cy Galley) 14. 05:48 PM - Re: Vortex generators installed (Richard Harris) 15. 05:52 PM - Re: building (Larry Bourne) 16. 06:06 PM - Re: Engine Cowling (CRAIG M NELSON) 17. 06:36 PM - Re: building (CRAIG M NELSON) 18. 08:31 PM - Re: building (woody) 19. 08:44 PM - Re: building/Base Coat Clear Coat (herbgh@juno.com) 20. 09:06 PM - Re: bent 4130 steel gear legs (Larry Bourne) ________________________________ Message 1 _____________________________________ Time: 05:28:28 AM PST US From: Subject: Kolb-List: Bob Brocious, are you out there? --> Kolb-List message posted by: Bob, If you are still lurking, drop me a note. Anybody know where he's at? The e-mail address I have for him bounced back to me last night. Denny Rowe rowedl@highstream.net do not archive ________________________________ Message 2 _____________________________________ Time: 08:20:59 AM PST US From: Gherkins Tim-rp3420 Subject: RE: Kolb-List: Engine Cowling --> Kolb-List message posted by: Gherkins Tim-rp3420 Uncle Craig, Sure is a beautiful cowl. Fun Huh? You forgot to mention all the complaining and profaning that I endured and listened to. Though I do admit, it is a work of art. It is also fun to work with an uncle that has the imagination and tenacity to tackle and finish such a project. I get to get a little hands on experience as well. Now uncle Craig wants to make a full cowl for my Rotax 503 on my Firestar II. Another project to tackle in the heat of next summer, now is the time to finish building and go flying for us south westerners. Still we are breaking record temperatures......today should be around 103 F in the Phoenix area. Nephew Tim G. still waiting for cooler painting weather?????and waiting and waiting and waiting.............................................................. -----Original Message----- From: CRAIG M NELSON [mailto:vitalfx0@msn.com] Subject: Re: Kolb-List: Engine Cowling --> Kolb-List message posted by: "CRAIG M NELSON" Richard: I don't know of a resource book, there is a company that I get my materials from here in Phoenix that I think might have some information. they just changed their name. next time I go I'll get you their address. composite work is fun and very rewarding. it's not that hard if I can do it any one can. Uncle Craig MKIIIex192uls Arizona do not archive ----- Original Message ----- From: Richard Swiderski Subject: Re: Kolb-List: Engine Cowling --> Kolb-List message posted by: "Richard Swiderski" Craig, You did what I only dreamed of! What a beautiful job. I've never done any glass work beyond patching an auto trunk deck. Is there a resource you could recommend that addresses the skills & materials needed to build a similar one? richard swiderski ________________________________ Message 3 _____________________________________ Time: 08:58:22 AM PST US From: "Richard & Martha Neilsen" Subject: Re: Kolb-List: Wings --> Kolb-List message posted by: "Richard & Martha Neilsen" I found a table VERY useful in building my airplane. I built the table from four cheep steel saw horses that had a 2*4 tops 24 inches long, one 4*8 sheet of 1/2 inch plywood, and some long 2*4s. I cut the plywood in half so that I had two 2*8 foot pieces. I spaced the saw horses evenly and set the plywood on them so I had a 2*16 foot table. I cut a bunch of short pieces of 2*4s and screwed them around the bottom edge of the plywood even with the edges. I then screwed the long 2*4s around the perimeter of the plywood even with the top of the plywood, screwing into the 2*4 blocks and saw horses. Be sure to make sure the table is flat and level as this will be used as the form for a bunch of the parts of the airplane. The plan was to use the table only for the airplane so I drew layout plans on the plywood and build the parts on the plans. I screwed blocks to the table where needed to keep parts straight while building and drilled holes to allow some parts to lay flat. When the plane was done I merely took the screws out to take the table apart. The wing could be build on a pair of saw horses because it has enough internal strength but things like flaps and ailerons need to be braced, blocked, or clamped to keep them straight when you build them. Rick Neilsen Redrive VW powered MKIIIc ----- Original Message ----- From: "James, Ken" Subject: Kolb-List: Wings > --> Kolb-List message posted by: "James, Ken" > > > O.K. lets go over wing building again. MKIII Xtra > > Saw horse? Table? Hanging? > > Who's got pics of there wings jigged up and what problems did you run into, > H beam placement , thrust tube ect.. > > Thanks for the help > ________________________________ Message 4 _____________________________________ Time: 09:17:58 AM PST US From: "Richard & Martha Neilsen" Subject: Re: Kolb-List: Engine Cowling --> Kolb-List message posted by: "Richard & Martha Neilsen" Craig As you can see there is allot of interest in your cowling. For now get your plane flying. From what I understand you now have a mold that more cowlings could be made from. Would you consider making/selling more cowlings, selling cowling kits, or selling the molds to someone that would produce them? When you get a chance would you share with me the rough inside dimensions of the cowling. I would REALLY like to put my VW in a cowling like that! Real airplanes have engine cowlings. Again get your plane flying and please share with us how it flies. Rick Neilsen Redrive VW powered MKIIIc ----- Original Message ----- From: "Gherkins Tim-rp3420" Subject: RE: Kolb-List: Engine Cowling > --> Kolb-List message posted by: Gherkins Tim-rp3420 > > Uncle Craig, > Sure is a beautiful cowl. Fun Huh? You forgot to mention all the complaining and profaning that I endured and listened to. Though I do admit, it is a work of art. > ________________________________ Message 5 _____________________________________ Time: 10:15:22 AM PST US From: "James, Ken" Subject: Kolb-List: Engine Cowling --> Kolb-List message posted by: "James, Ken" The cowling looks great!! I always thought the Kolb Aircraft looked unfinished with out a cowling, I plan to build a cowling myself and have may some prelim sketch's a couple of things I was toying with was a ground vent to open the top up while sitting on the ground so heat would not build up, Maybe a slim line electric fan etc. But the Kolb real does need a cowling to finish the look of the plane. Ken Ps. thanks for those who wrote back about the wings. will be starting this weekend! ________________________________ Message 6 _____________________________________ Time: 10:38:04 AM PST US Subject: Kolb-List: [ Audrey Lewis ] : New Email List Photo Share Available! From: Email List Photo Shares --> Kolb-List message posted by: Email List Photo Shares A new Email List Photo Share is available: Poster: Audrey Lewis Subject: Kolb Firestar II For Sale http://www.matronics.com/photoshare/audreylewis@alltel.net.10.21.2003/index.html o Main Photo Share Index http://www.matronics.com/photoshare o Submitting a Photo Share If you wish to submit a Photo Share of your own, please include the following information along with your email message and files: 1) Email List or Lists that they are related to: 2) Your Full Name: 3) Your Email Address: 4) One line Subject description: 5) Multi-line, multi-paragraph description of topic: 6) One-line Description of each photo or file: Email the information above and your files and photos to: pictures@matronics.com ________________________________ Message 7 _____________________________________ Time: 10:44:29 AM PST US Subject: Kolb-List: axle spacers From: ul15rhb@juno.com --> Kolb-List message posted by: ul15rhb@juno.com What are you guys using for wheel spacers on the axle? Steel seems like overkill and and weighs too much. I may have trouble finding thick-walled aluminum to fit over the 5/8" axle. How about PVC tubing? Anyone using that? Ralph Burlingame Original Firestar installing new axles ________________________________ Message 8 _____________________________________ Time: 12:18:53 PM PST US From: Jack & Louise Hart Subject: Re: Kolb-List: Wings --> Kolb-List message posted by: Jack & Louise Hart At 02:22 PM 10/20/03 -0400, you wrote: >--> Kolb-List message posted by: "James, Ken" > > >O.K. lets go over wing building again. MKIII Xtra > >Saw horse? Table? Hanging? > >Who's got pics of there wings jigged up and what problems did you run into, >H beam placement , thrust tube ect.. > >Thanks for the help > >Ken Ken, My shop is small so I built my wings on an open vertical wall. I attached a plate to the overhead truss in my shop and then used two by fours to make an open wall. I used lag screws with washers to attach some short horizontal pieces to a couple of the studs to support the main spar tube. I used a water level (tygon tubing partially filled with water with food coloring added) to level the tube with all ribs slid into position on the main spar. At this point the spar was made fast to the support and to the wall. Two plumb bobs were dropped so that they touched what would be the bottom side of the spar tube. Then the trailing edge tube was temporarily clamped to the two the outside full ribs. A third plumb bob was dropped to make sure that the steel inside rib was vertical and square to the main spar tube. Next the rear tube was supported so that it just touched the other two plumb bob strings. Then these supports were screwed to the studs to hold the trailing edge tub e in the correct position. (One of the tricks to getting things to level or line up is to use those little wood shims that are sold in hardware stores for leveling cabinets, etc.) Once this is done you can proceed with drilling and riveting the ribs to the tubes. Leave the water level and plumb bobs in place so that can see if you are warping the wing as you drill and rivet. All rib positions were measured from the inner most steel rib. This minimizes accumulative measurement error by measuring from one rib position to the next. There are several advantages to this method. 1) You can build the wing in space 5 feet wide and as long as the wing. 2) You can drill the holes and pop rivet on the bottom and top side of the wing while standing or sitting on either side of the wing. (For an old duffer like me not having to bend over is a plus.) 3) You can build the wing so that the bottom surface is square and it will be flat within 1/8 to 1/16 of and inch. I used lag screws to attach the studs to the plates. The studs were numbered, and so when I was done I disassembled the wall and slipped it up on top of the truss so that I can use it again for the next project. I temporarily stored all of the aluminum tubing in a ten foot long six inch PVC drain pipe that was tied just below the shop truss and just high enough so tha I would not hit my head but low enough so that I could pull out the tube size I wanted. My shop is small so the PVC end that you pull it out from should be pointed at the door. That gave me the room I needed to get the desired tubing out. (From Oct 14, 2000 and revised today.) Jack B. Hart FF004 Jackson, MO Jack & Louise Hart jbhart@ldd.net ________________________________ Message 9 _____________________________________ Time: 02:25:12 PM PST US From: HShack@aol.com Subject: Re: Kolb-List: Vortex Generators update - success! --> Kolb-List message posted by: HShack@aol.com In a message dated 10/20/03 7:34:33 PM Eastern Daylight Time, rwpike@charter.net writes: > Tomorrow I will peel off the tape that is holding the VG's temporarily in > place, paint them and rivet them in place, plus take off the gap seal and > add a couple to it also. As long as I have the center section working to > provide serious lift, might as well work it hard. Hope to have the web page > updated with pictures before the weekend. > > Richard Pike > Richard, put some on your vertical fin just in front of the rudder & get power steering. Howard Shackleford FS II SC ________________________________ Message 10 ____________________________________ Time: 04:01:19 PM PST US From: BKlebon@aol.com Subject: Re: Kolb-List: axle spacers --> Kolb-List message posted by: BKlebon@aol.com Let me look through my "remnants" and see if I can locate any of the extra aluminum tubing i used to make my axle spacers. If I find any I will send it to you. ________________________________ Message 11 ____________________________________ Time: 04:28:32 PM PST US From: Richard Pike Subject: Re: Kolb-List: Vortex Generators update - success! --> Kolb-List message posted by: Richard Pike Vince Nicely has persuaded me to gap seal the horizontal stab to the elevators, and I had planned to put some VG's in front of the stab bottom trailing edge, as the MKIII needs more elevator authority, so tell me more about how they affect the rudder? (Once you've already got 50 or 60 of the stupid looking things making your airplane look like a porcupine, what's a few more?) Richard Pike MKIII N420P (420ldPoops) At 05:21 PM 10/21/03 -0400, you wrote: >--> Kolb-List message posted by: HShack@aol.com > >Richard, put some on your vertical fin just in front of the rudder & get >power steering. > >Howard Shackleford >FS II >SC > > ________________________________ Message 12 ____________________________________ Time: 04:33:46 PM PST US From: "Paul Petty" Subject: Kolb-List: building --> Kolb-List message posted by: "Paul Petty" Kolbers, Well I finally finished those pesky elevators. Tonight I plan to fit the hinge's. Looks fairly easy. It's been 5 weeks since I received kit one and the horz. stabs and elevators are finally done. I have to get my steel parts to the paint shop soon as I will be building the vertical stab next. I have decided on a red and chrome yellow paint scheme with the fuselage tube and cage in red and the fuselage in yellow. If you look at the Kolbra demo plane, my plane will be yellow where the demo is white,red where the demo is purple and black where the stripes are orange. I like the demo's scheme. John Cooley and I talked about paint alot this past Saturday and both agree that auto paint would be fine for the final finish. A good high quality no doubt. I wonder if a base coat/clear coat system would work? Any thought's on this? Also any suggestions on the yellow color? later pp ________________________________ Message 13 ____________________________________ Time: 04:45:45 PM PST US From: "Cy Galley" Subject: Re: Kolb-List: Vortex Generators update - success! --> Kolb-List message posted by: "Cy Galley" Many vortex generators are simply glued on. That way if someone or thing hits them, they come off easily instead of damaging the area around them. ----- Original Message ----- From: Subject: Re: Kolb-List: Vortex Generators update - success! > --> Kolb-List message posted by: HShack@aol.com > > In a message dated 10/20/03 7:34:33 PM Eastern Daylight Time, > rwpike@charter.net writes: > > > > Tomorrow I will peel off the tape that is holding the VG's temporarily in > > place, paint them and rivet them in place, plus take off the gap seal and > > add a couple to it also. As long as I have the center section working to > > provide serious lift, might as well work it hard. Hope to have the web page > > updated with pictures before the weekend. > > > > Richard Pike > > > > Richard, put some on your vertical fin just in front of the rudder & get > power steering. > > Howard Shackleford > FS II > SC > > ________________________________ Message 14 ____________________________________ Time: 05:48:51 PM PST US From: "Richard Harris" Subject: Re: Kolb-List: Vortex generators installed --> Kolb-List message posted by: "Richard Harris" Jack that pop up that comes with you page keeps me from looking at any pics. What is that anyway? I have to reboot to continue. Richard Harris MK3 N912RH Lewisville, Arkansas DO NOT ARCHIVE ----- Original Message ----- From: "Jack & Louise Hart" Subject: Re: Kolb-List: Vortex generators installed > --> Kolb-List message posted by: Jack & Louise Hart > > Kolbers, > > One must be careful as to what effect your VG's are going to have and to understand what is going on. If you have them set so that they are over 45 degrees to the undisturbed air flow, you have a turbulator. This trips the boundary layer and causes the air to separate from the surface and to roll back over the wing. The roll axis is parallel to the wing surface and perpendicular to the undisturbed air flow. In the case of turbulators, you actually decrease lift and so increase stall speed and parasitic drag. This is why they are used inboard on wing to cause the inner most section of the wing to stall before the outer portion. > > The trick of VG's is to keep the angle to the undisturbed air flow as small as possible and to form little swirls whose axis is perpendicular to the wing. This minimizes parasitic drag. They delay boundary layer thickness formation, and as result, they delay overall laminar airflow separation from the wing until the air has passed further back over the wing. For a given speed and angle of attack the wing will produce more lift and the center of lift will move toward the rear. So if one is going to continue to cruise at the same indicated air speed, the angle of attack will be reduced until the wing is developing the same total lift as it was before the VG's were installed. > > The FireFly wing is a high camber wing, and high camber wing induced drag changes rapidly with angle of attack. So anything one can do to reduce the cruise angle of attack and for a given power input, it will give a better cruise speed. > > If you are not copying a proven set up from another plane, I believe the best way to determine what is best for your plane is to make up a bunch of them and tape them on the wing with electricians tape. Start out with a few and keep adding on successive flights to determine what is best. The easiest test is to use a hard surfaced runway, and to nurse the plane off into ground effect. As you add VG's the indicated airspeed will decrease at which the plane will lift off. At some point the adding of VG's will have no effect and this determines how many to put on. Then the plane is ready to go to altitude for slow flight and stall tests. You will be amazed at how slow it will fly, and how stable it has become. > > In my case the FireFly has 18 VG's on each wing. No way would I take them off. I can fly any time of the day through just about anything. Whoops! I have been gone a few days and I am starting to ramble. If you are interested, you can see them starting at: > > http://www.thirdshift.com/jack/firefly/firefly17.html > > These VG's have been mounted for over three years with some of them inside the propeller arc, and none have come loose. > > Jack B. Hart FF004 > Jackson, MO > > > Jack & Louise Hart > jbhart@ldd.net > > ________________________________ Message 15 ____________________________________ Time: 05:52:47 PM PST US From: "Larry Bourne" Subject: Re: Kolb-List: building --> Kolb-List message posted by: "Larry Bourne" This, too, has been discussed before, and it seems to me that the general consensus was that many auto paints aren't flexible enuf to perform well on fabric, and tend to crack. I understand there are flex agents available for some paints, so it'd be something for you to check out. A call to Jim & Dondi might be a good idea. Lar. Larry Bourne Palm Springs, CA Kolb Mk III - Vamoose N78LB www.gogittum.com ----- Original Message ----- From: "Paul Petty" Subject: Kolb-List: building > --> Kolb-List message posted by: "Paul Petty" > > Kolbers, > Well I finally finished those pesky elevators. Tonight I plan to fit the hinge's. Looks fairly easy. It's been 5 weeks since I received kit one and the horz. stabs and elevators are finally done. I have to get my steel parts to the paint shop soon as I will be building the vertical stab next. I have decided on a red and chrome yellow paint scheme with the fuselage tube and cage in red and the fuselage in yellow. If you look at the Kolbra demo plane, my plane will be yellow where the demo is white,red where the demo is purple and black where the stripes are orange. I like the demo's scheme. John Cooley and I talked about paint alot this past Saturday and both agree that auto paint would be fine for the final finish. A good high quality no doubt. I wonder if a base coat/clear coat system would work? Any thought's on this? Also any suggestions on the yellow color? > > later > > pp > > ________________________________ Message 16 ____________________________________ Time: 06:06:37 PM PST US From: "CRAIG M NELSON" Subject: Re: Kolb-List: Engine Cowling --> Kolb-List message posted by: "CRAIG M NELSON" Rick yes I do have molds for the cowling and plan to sell cowl kits. I am going to test fly it to see how it performs i.e.. cooling, if the planning is correct the engine should run cooler and the cruse should be 5 to 6 mph faster. it will sure clean the air that the prop is exposed to. Uncle Craig MKIIIex912uls Arizona ----- Original Message ----- From: Richard & Martha Neilsen Subject: Re: Kolb-List: Engine Cowling --> Kolb-List message posted by: "Richard & Martha Neilsen" Craig As you can see there is allot of interest in your cowling. For now get your plane flying. From what I understand you now have a mold that more cowlings could be made from. Would you consider making/selling more cowlings, selling cowling kits, or selling the molds to someone that would produce them? When you get a chance would you share with me the rough inside dimensions of the cowling. I would REALLY like to put my VW in a cowling like that! Real airplanes have engine cowlings. Again get your plane flying and please share with us how it flies. Rick Neilsen Redrive VW powered MKIIIc ----- Original Message ----- From: "Gherkins Tim-rp3420" Subject: RE: Kolb-List: Engine Cowling > --> Kolb-List message posted by: Gherkins Tim-rp3420 > > Uncle Craig, > Sure is a beautiful cowl. Fun Huh? You forgot to mention all the complaining and profaning that I endured and listened to. Though I do admit, it is a work of art. > ________________________________ Message 17 ____________________________________ Time: 06:36:35 PM PST US From: "CRAIG M NELSON" Subject: Re: Kolb-List: building --> Kolb-List message posted by: "CRAIG M NELSON" Paul: It's exciting to see the tubes start to take the shape of a dream of a life time, an airplane made by your own hands. I looked at the Kolbra and envisioned it in the colors you described. It'll be awesome. I might re think the paint though. those automotive paints have solvents in them that make the paint brittle after 2 years. I know a lot of kolbers don't like aerothane because they say it is hard to use. but it makes a finish that will last years. Jim & Dondie the polyfiber distributor have a steerman that the paint is 20 years old and it looks like it was painted yesterday and does it shine!!!!!!! Uncle Craig MKIII912uls Arizona do not archive ----- Original Message ----- From: Paul Petty Subject: Kolb-List: building --> Kolb-List message posted by: "Paul Petty" Kolbers, Well I finally finished those pesky elevators. Tonight I plan to fit the hinge's. Looks fairly easy. It's been 5 weeks since I received kit one and the horz. stabs and elevators are finally done. I have to get my steel parts to the paint shop soon as I will be building the vertical stab next. I have decided on a red and chrome yellow paint scheme with the fuselage tube and cage in red and the fuselage in yellow. If you look at the Kolbra demo plane, my plane will be yellow where the demo is white,red where the demo is purple and black where the stripes are orange. I like the demo's scheme. John Cooley and I talked about paint alot this past Saturday and both agree that auto paint would be fine for the final finish. A good high quality no doubt. I wonder if a base coat/clear coat system would work? Any thought's on this? Also any suggestions on the yellow color? later pp ________________________________ Message 18 ____________________________________ Time: 08:31:30 PM PST US From: "woody" Subject: Re: Kolb-List: building --> Kolb-List message posted by: "woody" I have painted two aircraft with a system called Hi Pec, I think it may be called Endura now. It is a 2 part urethane auto paint with a flex agent in it. It has worked good for me but you may also need to add an activator to the mix. I didn't know about this and it took the paint 12 hours to dry. Some runs and a lot of bugs came over to see what I was doing. both agree that auto paint would be fine for the final finish. A good high quality no doubt. I wonder if a base coat/clear coat system would work? Any thought's on this? Also any suggestions on the yellow color? ________________________________ Message 19 ____________________________________ Time: 08:44:43 PM PST US Subject: Re: Kolb-List: building/Base Coat Clear Coat From: herbgh@juno.com --> Kolb-List message posted by: herbgh@juno.com Paul My Zmax was finished with base coat clear coat some 5 years ago. It looks as slick and shiny as any paint job that I have ever seen on an aircraft. Naturally I did not build the plane nor paint it!! I have been told by a PHD chemist that clear coat with uv block performs as good or better than the traditional method of using an aluminum based undercoat. Looking on the can; I think it is called Sherwin Williams ultra one stage or Ultra 7000?? It is painted in a yellow,blue and red scheme. I have noticed that the yellow,which is the predominant color, is usually quite a bit hotter on a sunny day and all of the bugs seem to be attracted to that color. The plane has several hangar rash spots but none since I acquired it two springs ago. I have been watching to see if the paint will begin to craze or crack. So far so good! Herb On Tue, 21 Oct 2003 18:38:06 -0500 "Paul Petty" writes: > --> Kolb-List message posted by: "Paul Petty" > > Kolbers, > Well I finally finished those pesky elevators. Tonight I plan to fit > the hinge's. Looks fairly easy. It's been 5 weeks since I received > kit one and the horz. stabs and elevators are finally done. I have > to get my steel parts to the paint shop soon as I will be building > the vertical stab next. I have decided on a red and chrome yellow > paint scheme with the fuselage tube and cage in red and the fuselage > in yellow. If you look at the Kolbra demo plane, my plane will be > yellow where the demo is white,red where the demo is purple and > black where the stripes are orange. I like the demo's scheme. John > Cooley and I talked about paint alot this past Saturday and both > agree that auto paint would be fine for the final finish. A good > high quality no doubt. I wonder if a base coat/clear coat system > would work? Any thought's on this? Also any suggestions on the > yellow color? > > later > > pp > > > = > = > = > = > > > > > > ________________________________ Message 20 ____________________________________ Time: 09:06:59 PM PST US From: "Larry Bourne" Subject: Re: Kolb-List: bent 4130 steel gear legs --> Kolb-List message posted by: "Larry Bourne" This makes me curious about a couple of things. Your gear legs are .095 wall x 1 .125 dia., heat treated to R42, and you bent them with a FireStar. OK............John Hauck's (and mine) are .125 wall x 1.125 dia., and John's are heat treated to R48. Thicker wall, sure, (33% ??) but Miss P'fer is much heavier, (more than double) and has made many landings on rough strips at well over 1,000 lbs. Is the difference between R42 and R48 that great ?? I've heard before about some heat treat-ers only being able to get up to, say, R45, and in 1 case at least, seems to me that was sufficient. What is so different about R45 and R48, that some shops can get up to one and not the other ?? Seems like it would just be a matter of their skill ?? How can you tell if your shop really DID get R whatever, as they claim ?? I'm VERY interested - my A&P is finally in gear, and Vamoose' gear legs should be going to the heat treating shop by next Monday. BTW..............lots and lots of the 7075 legs have been bent, too, and seems like it's rare with the 4130. Concerned Lar. Larry Bourne Palm Springs, CA Kolb Mk III - Vamoose N78LB www.gogittum.com ----- Original Message ----- From: "Ben Ransom" Subject: Kolb-List: bent 4130 steel gear legs > --> Kolb-List message posted by: Ben Ransom > > Just over a month back in the air and I find that I have bent my 4130 > steel tube gear legs. Mine are 1.125" diameter x .095 wall thickness, > heat treated to Rockwell 42. I landed yesterday on a long sandbar on > the Sacramento River about 5 miles south of Colusa. The sandbar had > some gradual steps, but enf to give me a couple of pretty good bounces > after a faster than ideal touchdown. I didn't notice the bent legs > until getting back home and seeing the plane on flat pavement, but it > is obviously listing to starboard. > > My first inclination is to go back to the factory 7075 aluminum legs as > I had abused them similarly to yesterday's rough stuff without bending > them. As for the steel leg options, I could get the same legs and find > a heat treater that could get them up to 46-48 Rockwell, but today I'm > feeling greatful that yesterday's incident was bent legs instead of > broken legs. Or, I could go to a bigger wall thickness, but I'm > already paying a minor weight penalty over aluminum for the 1.125x.095. > > > I'd really like to keep the gear legs pushed all the way to the top of > the cage sleeves, so if I go to 7075, does anyone know which particular > 7075 alloy this is, and possibly a good source? I can take care of the > tapering lathe work no problem. > -Ben > > ===== > http://mae.ucdavis.edu/~ransom > > __________________________________ > >