I need help with a lateral balance problem.
 

I have an Edge 540 Freestyle (Fliton) and I am using an OS 70 Surpass four stroke engine. The problem is that the plane is balanced on the CG but laterally it is heavy on the motor side. I must trim the ailerons to hold the heavy side down to get level flight. If I add weight to the light side it might be worse. I'm confused. Any help would be appreciated.

RE: I need help with a lateral balance problem.
 

I believe you meant to hold the heavy side up.

Add enough weight at the tip of the wing on the light side and in line with the CG if possible.

You may find the following link useful:

http://www.masportaviator.com/ah.asp?CatID=8&ID=144

RE: I need help with a lateral balance problem.
 

there are lots of ways to do it.

Get the plane setup so that its lifted by the crank and tail..so you can see how far its off. Obviously if you have a bunch of right thrust in the motor that will mean you can't get an accurate balance from the crank if its off center..

If its not off by much and you have kit experience you might be able to remove some weight from the heavy side wingtip.

This of course depends on your knowlege of building and the way the plane is costructed.

If any of your radio is mounted in the wing can you move it or the battery around? To your advantage....


Otherwise you will propably have to add lead weights to the light side until it balances. Set the lead way out where it can be mounted in a hole or access panel of some type...If you have to add weight a scratch built hatch won't hurt you. Hopefully you only need to drill a hole and glue in a tiny bit of lead..

Might be some better ideas coming along, but this will let you start pondering it. Good luck!

RE: I need help with a lateral balance problem.
 

I'm going to assume that your forth sentence is correct. The aileron trim you are putting in may be because your rudder or vertical stab is not in line. You must laterally balance it and then deal with whatever other problems show up. Balance it by adding weight to the light side, say the left wing tip. Now look for something wrong with the fuselage/vertical stab/rudder. Correct anything, neutralize all of the trims, and make a test flight. Is the engine thrust set correctly?

RE: I need help with a lateral balance problem.
 

Thanks for the replies. I will explain it better. If I set all my control surfaces to neutral and take off I will need to trim my ailerons to the right quite a bit to get level flight. That's the heavy side of the plane. I'm scared to add weight to the light side to balance it as I think it will be worse. Thanks for your replies.

RE: I need help with a lateral balance problem.
 

kcrooks:

You are correct, since, according to your last post, it seems that you have more than a lateral balance problem.
If you need to trim the ailerons to the right is because you have a force trying to roll your model to the left for zero trim.
Hence, adding weight to the left side will worsen things.

You need to perform a full trim to your model.
However, start with a static pitch and lateral balance, as explained above.
Use any of the trim charts that can be found on-line, adjusting it to your type of model.

See example following the link:
http://www.lferc.com/Tips/trim_chart.php

RE: I need help with a lateral balance problem.
 

Wings/stab/elevator halfs may have a slight warp/incidence difference.<div>Get an incidence meter and check everything.</div>

RE: I need help with a lateral balance problem.
 

As mentioned by others you might have problems with incidence or twist of the flying surfaces in addition to possible lateral balance issues.  Do use an incidence meter at the root and tip of each wing to check for wing twist, then twist the wing by hand and use a heat gun to reshrink the covering to reset the twist.</p>

The best way to test lateral balance is in flight.  Trim your plane out for straight and level flight.  Make long passes back and forth without touching the ailerons, trim it in roll as accurately as you can.</p>

Then set up for a long pass and roll inverted.  Make a long pass using only elevator, do not touch the ailerons, and check if the plane flies wings level clear across the field or if it tends to roll one way or the other.  Repeat this test many times.  If it rolls to the right when inverted the left wing is heavy and of course if it rolls to the left, the right wing is heavy.  Add a chip of stick on lead to the light wing tip and test it again.</p>

When the plane trims out in roll the same upright as inverted, it is laterally balanced.  Any differences left in the aileron trim at that point will be mostly due to twists of the aero surfaces.</p>

This is an important trim step with any new plane.  Lateral balance affects tracking on all looping maneuvers and trim while inverted.</p>

Dave</p>

RE: I need help with a lateral balance problem.
 

Thank you to all you replied to my problem. I have received a lot of information and I am currently checking this model very closely for the problem. The next time I get it in the air I will let you know how it goes. Thank you again.

RE: I need help with a lateral balance problem.
 

Generally it's better to remove weight from the heavy side rather than add weight to light side.</p>

Mike</p>