A question of Balance

[Dai Fledermaus]

I need your help again fellers

I'm about to cover the wing on the Tyro Major I've built, but I've noticed that the wing doesn't balance. it falls consistantly to the port side even when the starboard side is pushed down to a flat surface. I don't understand why because the same grade and thickness of balsa was used on both sides. The weight needed to get it to balance is probably not more than a few grams, because it doesn't register on our kitchen scales, but that's probably not very accurate

Should I add a little weight to the starboard wing tip to make it balance before covering or should I not worry about it. It seems to me that there are other factors which could affect the balance of the model. For example, would the position of the three servos have an effect? What about the silencer on the engine? The wing is banded on, if this were not prefectly central this would also affect the balance - wouldn't it?

How critical is it to make sure the assembled model is perfectly balanced?

[Bill Brown 3]

Best wait for advise from those who would know better than i Colin but i had this problem on the wing of a build and rectified it by adding a wooden block to the lighter side thus ensuring that the wing in its self was balanced.

[Greybeard]

In my view it is not critical and I would wait until the model is finished before worrying about lateral balance.

[crispin church]

what does the whole plane balance like ?

[Paul Adams]

Wait until you have the complete model built and assembled as the engine / motor, batteries undercarriage, covering, painting, trim etc can also effect the balance. Once complete balance the model to obtain the required C of G and then laterally balance the model. Weight can be added to the light side using panel pins. screws of if a long way out lead.

[PMIKEY]

If the model was an all moulded glider or an f3a pattern ship i would be crying into my soup over a lateral balance issue but with a "Tyro Major" i would not lose any sleep about a couple of grams indifferance between each side. Even if you do finish the model to an anal standard and measure the wing each time you band it on, i can almost garantee 100% that you will never notice.

Happy landings.

Mike

[cymaz]

While you can get into hide the lead weight , put everything altogether ( and I mean everything) lateral balance it and put the mass in the light wing. You know at least the plane will be OK in that area.

[The Wright Stuff]

With the absence of any ailerons to trim out any rolling moment, I'd be tempted to get it as close as possible. Having said that, if it's only a couple of grams, any slight mass assymetry is likely to be overshadowed by engine torque, and tiny assymetries in the wing shape anyway.

I remember my very first built-up plane - one wing was exactly a penny's weight lighter than the other - so guess what I glued in there!

 

Edited By The Wright Stuff on 05/04/2013 12:52:21

[crispin church]

you can all ways put a hole in end wing add hot glue and weight when finished

[Biggles' Elder Brother - Moderator]

I'd balance at the end - its only a fraction out, that could disapear in siting other stuff in the model.

Generally you should try to get the lateral balance "OK" on any model. Its just one more factor to worry about otherwise. But don't get too hung up on it. When you are using the model regularly you could have a couple of grams "out of lateral balance" due to a bit mud stuck to one wing!

So the message is:

1. Try and get it more or less right once the model is assembled.

2. Dont get to obssessed by it

3. Remember - small inbalances and imperfections are what aileron trim is for!

BEB

[Dai Fledermaus]

Thanks for your help everyone. Cols