How to adjust cg
05-28-2007, 10:16 AM
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How to adjust cg
Ok from what I understand my cg is 4 inches behind the leading edge. now should I balance my plane so it stays level if supported from the two cg points , one on each wing. I appreciate the help
05-28-2007, 10:20 AM
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RE: How to adjust cg
This is correct. Do this with an empty tank. I use some pieces of masking tape cut into points to mark where the CG should be so I know exactly where this is. Move your battery if you can to help with balancing. Wing will be on top when balancing (low wing plane would be inverted when balancing).
If you're having trouble getting this spot on, note that it's better to have your CG slightly forward but not behind the suggested CG point(nose heavy vs tail heavy). Tail heavy can make a plane squirrely.
somegeek
If you're having trouble getting this spot on, note that it's better to have your CG slightly forward but not behind the suggested CG point(nose heavy vs tail heavy). Tail heavy can make a plane squirrely.
somegeek
05-28-2007, 10:33 AM
#3
RE: How to adjust cg
take a permament marker and mark the cg range on the inside of each fuselage side for future reference.that way you will know what it should be if/when you misplace the manual/plans.
05-28-2007, 10:46 AM
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RE: How to adjust cg
ORIGINAL: aerowoof
take a permament marker and mark the cg range on the inside of each fuselage side for future reference.that way you will know what it should be if/when you misplace the manual/plans.
take a permament marker and mark the cg range on the inside of each fuselage side for future reference.that way you will know what it should be if/when you misplace the manual/plans.
somegeek
05-28-2007, 01:49 PM
#6
RE: How to adjust cg
Before you mark the fuse, fly the plane and make sure the CG is where you want it.
Remember that there is a cg "Range" about 1/2 to 1" wide (Depending on the plane)
The recommended CG is often just a starting point.
Once you fly it, you mat want to move the CG a little
Once you get it where you want it, mark that spot
Remember that there is a cg "Range" about 1/2 to 1" wide (Depending on the plane)
The recommended CG is often just a starting point.
Once you fly it, you mat want to move the CG a little
Once you get it where you want it, mark that spot
05-29-2007, 08:51 AM
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RE: How to adjust cg
I will qualify my answer by saying I am a beginner also, however, I have spend quite a bit of time researching CG on my Great Planes PT 40 trainer. You didn't mention what kind of plane you had for your CG issue. I would suggest you spend some time learning about CG - it could save your plane. Most, if not all, trainers are designed to balance on the main wing spar. If your wing spar is 4" from the LE, then you should be all set. I built a simple little balancing jig - piece of plywood with two dowels topped with pencil erasers. Place it at the 4" mark and let it balance level. (Slight nose heavy is preferred as others have mentioned).
Also, check your build plans and instructions. My PT40 plans had the CG at about 4" and that was incorrect. First flight by my instructor/test pilot was scarry to say the least, but managed to bring it down in one piece. Change the CG to balance on the spar - which was 3 1/2" and what a difference. Flys great now.
Also, check your build plans and instructions. My PT40 plans had the CG at about 4" and that was incorrect. First flight by my instructor/test pilot was scarry to say the least, but managed to bring it down in one piece. Change the CG to balance on the spar - which was 3 1/2" and what a difference. Flys great now.
