I maidened a Venus .40 today and have a question about lateral balance and trim that came up. I balance the plane laterally at home and had to add weight to the left wing to get it balanced correctly. When I flew it today I had to add about 8 clicks of right trim on the ailerons to get it to fly wings level. It was as if the left wing was too heavy.

I was wondering if anyone had a suggestion as what to do. Remove the weight on the left wing and try it that way, or something else. I mounted the engine so it is at a 45* down angle and not completely inverted.

I was only able to get one short flight on it before I had to pack up because of rain. I did find that it flies Just like the larger Venus II, and she's a keeper!

Edit - The ailerons are both in the same neutral position, I don't believe they caused the roll.

I think I'd re-balance again to recheck the balance again. Its also possible that your control surfaces are not equal giving you the roll. Try a more dynamic balance check by tying a large loop around the fuselage, then attach the wing setting the loop where it exits the wing saddle on the CG points on each side of the fuselage. Hang the airplane from the loop with a cord a few inches above the floor and see how it balances.

Don't have the Venus 40 should be a great performer just like the Venus II which I'm currently flying.

It's most likely what Steve said, time to double check the balance job.
If the wing has a twist, you will be able to see it with a trained eye from well behind the plane, at eye level. Most .40 sized planes can be eyeballed [for a twist or warp] at arms' length.

Lateral balance was correct, I checked it again and it is heavy on the right side. Checked the wing and no twist or warp. I think I am just going to remove the weight on the left side of the wing and fly it and see what happens.

Before you remove the weight, try this.

On a nice calm night, fly straight and level and make sure the ailerons are trimmed so it flies "Hands off"

Now roll to inverted and see if it still flies "hands off"

If one wing is heavy, it will need to have that aileron lowered to make it fly "Hands off" But when you fly inverted, that aileron is now "Up" which is pushing the heavy wing down - so it will want to roll out of the inverted position.

But if the plane is laterally balanced, even if the ailerons don't seem to be even, it should still fly correctly whether right-side-up or inverted.

With the radio turned on and the plane on the work bench, those 8 clicks of trim should reveal where something isn't right. The gear train of your aileron servo is OK I hope?

MinnFlyer - Thanks, that is just the information I was looking for. It was so windy yesterday all I could do was fly the pattern and do some figure 8 circuits. Everything else about the plane seemed right on. I'll fly it inverted next time out.

Thanks again.

another way to check laterail balance is a big loop, go slow at the top...if it always rolls out to the same side your heavy on that side...landing is another way to tell, if you're way heavy on a side, as you flair for landing the airplane will seem like it tip stalls.....

Not to negate the need to lateral balance. However, there are other forces, such as drag that also enter picture as well as overall alignment of stab, elev.,vertical fin, rudder. the fact that the engine is mounted on an angle and the muffler is also on one side of fuselage definitly changes the center of lateral area as well as drag thereby quite likely requireing some trim to be required. Assuming all flying surfaces are perfectly aligned? I would suggest removing perhaps 1/2 the weight on wing. Trim is there to be used if and when necassary to compensate for a variety of things. Just don't use it to overcome poor alignment or warps.