---------------------------------------------------------- Kolb-List Digest Archive --- Total Messages Posted Wed 10/06/21: 6 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:57 AM - Re: Re: Mark III weight and balance (Franklin Geiser) 2. 05:35 AM - Re: Mark III weight and balance (Richard Pike) 3. 05:44 AM - Re: Re: Mark III weight and balance (Franklin Geiser) 4. 09:35 AM - Re: Re: Mark III weight and balance (Jay Dub) 5. 10:14 AM - Re: Re: Mark III weight and balance (Franklin Geiser) 6. 05:20 PM - Re: Re: Reducing power on take off versus thrust line. (william sullivan) ________________________________ Message 1 _____________________________________ Time: 04:57:30 AM PST US From: Franklin Geiser Subject: Re: Kolb-List: Re: Mark III weight and balance My "yellow book" is a small book of builders plans, no w&b info. I've got a blue book though that doesn't have any forms, but does tell me that 25-35% is the range at 9 degrees, and 66" is the average chord, so I just worked off of that. My measurements for the main arm and tail arm are pretty much identical to yours (I figured the tail wheel was 1/2" farther back) Have you ever measured weights fully loaded, with the pilot and all? Rather than estimating moments for the pilot/gas/parachute, I just went the route of weighing the entire craft with me in it. I did also weigh it without me, and did some reverse calculations to come up with the pilot/passenger arm measurement, and I decided that it's actually a positive 0.15" for myself instead of the -5" that you used. That's a change of about 3% forward with no passenger, and nearly 10% with a passenger also - not saying that yours is wrong at all, but if I used that number, I wouldn't have nearly as much weight on the floor either. I was bumping up against the top limit of my scales, so I couldn't weigh with a passenger also. I do have a pair of 660lb scales on order though, and will get some actual measurements with those this weekend. Some of my measurements didn't quite work out right, so I have some concerns about the quality of my scales (nice shipping scales I was able to borrow, but needed to use two per wheel as they maxed out at 150lb) On Tue, Oct 5, 2021 at 10:19 PM Richard Pike wrote: > > Something doesn't sound right. I have done a lot of mods to my MKIII but > nothing to move the weight fore or aft much, I have a 582 and need no > ballast. > I assume you are using the Kolb forms on page 41, 42 & 43 of "The Yellow > Book"? If not, PM me, I'll email them to you. FWIW, here is my W&B: > > -------- > 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=503443#503443 > > > Attachments: > > http://forums.matronics.com//files/mkiii_wandb_166.jpg > > ________________________________ Message 2 _____________________________________ Time: 05:35:00 AM PST US Subject: Kolb-List: Re: Mark III weight and balance From: "Richard Pike" Here are the forms: You don't have to actually sit in the airplane or have your pax sit in it; figure out where the bellybutton is going to be and compute the weight from the datum to that point. -------- 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=503458#503458 Attachments: http://forums.matronics.com//files/dwg41_144.jpg http://forums.matronics.com//files/dwg42_137.jpg http://forums.matronics.com//files/dwg43_240.jpg ________________________________ Message 3 _____________________________________ Time: 05:44:32 AM PST US From: Franklin Geiser Subject: Re: Kolb-List: Re: Mark III weight and balance Thanks for the pages! I understand that the navel is generally thought to be the cg of the seated person, but that's got to vary by person/build/weight as well. Seems to me that simply weighing all together takes out that variable (though of course you don't want to weigh the craft again for every new passenger, so an average is probably a good idea) On Wed, Oct 6, 2021 at 8:37 AM Richard Pike wrote: > > Here are the forms: > You don't have to actually sit in the airplane or have your pax sit in it; > figure out where the bellybutton is going to be and compute the weight from > the datum to that point. > > -------- > 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=503458#503458 > > > Attachments: > > http://forums.matronics.com//files/dwg41_144.jpg > http://forums.matronics.com//files/dwg42_137.jpg > http://forums.matronics.com//files/dwg43_240.jpg > > ________________________________ Message 4 _____________________________________ Time: 09:35:53 AM PST US From: Jay Dub Subject: Re: Kolb-List: Re: Mark III weight and balance On thing I haven't seen mentioned, does the original poster have the aircraft setup according to level flight? What I mean is most tailwheel airplanes need to have the tail raised to a certain position for level flight when using the scales to determine w&b. If the scale is on the floor instead of raised up, it would show more weight on the tail which would make it seem more ballast is needed up front. That leveling process should be spelled out on the w&b sheet in the drawings. If the OP doesn't have the drawing maybe someone can take a photo of that page. Just a thought. Jaydub ________________________________ Message 5 _____________________________________ Time: 10:14:15 AM PST US From: Franklin Geiser Subject: Re: Kolb-List: Re: Mark III weight and balance Yeah, I've got a block under the tailwheel to bring the bottom of the wing up to 9 degrees, as specified in the manual. On Wed, Oct 6, 2021 at 12:40 PM Jay Dub wrote: > > On thing I haven't seen mentioned, does the original poster have the > aircraft setup according to level flight? What I mean is most tailwheel > airplanes need to have the tail raised to a certain position for level > flight when using the scales to determine w&b. If the scale is on the > floor instead of raised up, it would show more weight on the tail which > would make it seem more ballast is needed up front. That leveling process > should be spelled out on the w&b sheet in the drawings. If the OP doesn't > have the drawing maybe someone can take a photo of that page. Just a > thought. > > Jaydub > > ________________________________ Message 6 _____________________________________ Time: 05:20:06 PM PST US From: william sullivan Subject: Re: Kolb-List: Re: Reducing power on take off versus thrust line. My comment referred to picking up the prop end of the engine- the end clos est to the tail. Bill Sullivan On Wednesday, October 6, 2021, 12:37:22 AM EDT, lane jones wrote: I think maybe it would be a good idea to define front and rear of engine. =C2- It sounds to me like everyone doesn=99t have the same understa nding.=C2- Lane Jones Kolb Mark III xtra 912 rotax =C2- From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@m atronics.com]On Behalf Of william sullivan Sent: Tuesday, October 05, 2021 11:20 AM Subject: Re: Kolb-List: Re: Reducing power on take off versus thrust line. =C2- If you pick up the rear, it will push the nose down. Imagine picking up the rear about 2 feet. On Tuesday, October 5, 2021, 01:48:07 AM EDT, chic wrote : =C2- =C2- =C2- Okay, so I am a little confused here..... If I raise (just) the rear of the engine on my Firestar 2 for more prop clearance off the boom tube, am I ad ding positively or negatively to the thrust line? =C2- =C2- =C2- =C2- Read this topic online here: =C2- http://forums.matronics.com/viewtopic.php?p=503414#503414 =C2- =C2- =C2- =C2- =C2- =C2- http://www.matronics.com/Nav=C2- =C2- =C2- =C2- =C2- =C2- - MAT RONICS WEB FORUMS - >http://forp; =C2- =C2- =C2- =C2- =C2- =C2- - NEW MATRON ICS LIST WIKI -http://wiki.matronics.com http://www.matronics.c =C2- =C2- =C2- ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message kolb-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Kolb-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/kolb-list Browse Digests http://www.matronics.com/digest/kolb-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.