RCU Forums - Balance question

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Balance question

A Goon question:

I have a GP Revolver with a .75 ax in it. I flew it and it was pretty schetchy. After flight, on the balance.....i had to add .5 ounce lateral, and 3oz to the tail to get it right. I moved the battery more to lessen the added weight. originally, It was a handfull to fly, snaping out of any hard up elevator, just sketchy everywhere. are those unbalance figures considered alot for a 40 size plane and could be the culprit to the very poor flying, or should i be looking elsewhere on the plane?

Thanks

871

RE: Balance question

I'm not sure I understand what you did with that weight. But it sounds like you flew the model the first time without checking the balance at all and then added these weights and moved the parts in order to move the balance location to where it is supposed to be according to the instructions. If so then yes, it's quite normal to have to do so. Variations in wood density, engine and radio equipment choices and a host of other variables make it impossible for an ARF maker to ensure that the balance point comes out spot on for you. Setting the balance point is something you need to do with ANY new model.

RE: Balance question

Quote:

ORIGINAL: BMatthews

I'm not sure I understand what you did with that weight. But it sounds like you flew the model the first time without checking the balance at all and then added these weights and moved the parts in order to move the balance location to where it is supposed to be according to the instructions. If so then yes, it's quite normal to have to do so. Variations in wood density, engine and radio equipment choices and a host of other variables make it impossible for an ARF maker to ensure that the balance point comes out spot on for you. Setting the balance point is something you need to do with ANY new model.

Basically in a nut shell I did a quick balance (close), then changed the muffler added the cowl and flew it without rechecking it. Both times it flew badly. I had to add 3oz to the end of the tail to get it to balance right, .5 oz to l wing tip. Would this amount of unbalance make it fly like a POS on my previous flights? or should I check elsewhere?

RE: Balance question

I have an OS FS-70 powered Revolver and did a kit review for R/C Report magazine. Balanced correctly at 110mm. it is an excellent flying plane.

You did notice the control movements, I hope. Low rate on elevator is only 5/16" each way and high rate is 1/2" each way. This is not very much.

If you use excessive movement, you can easily snap the plane. Bear in mind it is not a 3D plane for doing hard up walls, but more of a sport pattern type plane. If you are used to a very light 3D plane with a thick airfoil, you'll have to learn how to fly this plane, which is heavier and has a thinner airfoil. It does snap fairly fast, but it is controllable. An avalanche is one maneuver where you use a snap and it's easy to do.

The low speed handling is also good, but bear in mind it isn't going to slow to a crawl like a light 3D plane.

You might also want to put in some exponential on the elevator for smoother control input.

RE: Balance question

Quote:

ORIGINAL: show871

Would this amount of unbalance make it fly like a POS on my previous flights? or should I check elsewhere?

Even though you didn't define POS other the snaps I would say you may need to look elsewhere. A nose heavy airplane is overly stable until you run out of elevator. Moving the CG back may make things worse. Check the throws like Ed says.

RE: Balance question

Quote:

ORIGINAL: Ed_Moorman

I have an OS FS-70 powered Revolver and did a kit review for R/C Report magazine. Balanced correctly at 110mm. it is an excellent flying plane.

You did notice the control movements, I hope. Low rate on elevator is only 5/16" each way and high rate is 1/2" each way. This is not very much.

If you use excessive movement, you can easily snap the plane. Bear in mind it is not a 3D plane for doing hard up walls, but more of a sport pattern type plane. If you are used to a very light 3D plane with a thick airfoil, you'll have to learn how to fly this plane, which is heavier and has a thinner airfoil. It does snap fairly fast, but it is controllable. An avalanche is one maneuver where you use a snap and it's easy to do.

The low speed handling is also good, but bear in mind it isn't going to slow to a crawl like a light 3D plane.

You might also want to put in some exponential on the elevator for smoother control input.

Flew again today, and I think you are right.....I was just expecting a different airplane. To be honest I could not see the thing clearly....am just that gave my the chills. I am going to sell it and maybe get a small yak, or some aerobatic/3d 50-60"ws. Suggestions?

RE: Balance question

Did you check for warps?