How critical is Lateral balance for a sport flyer?

I am just finishing up my TF Contender and I will need to ad 1oz of weight to my left wingtip to get the lateral balance to come out perfectly. The CG balance point is fine.

I balanced everything before I covered it with the battery, servos, receiver and engine mounted. It seemed pretty close then. Now I have the 1oz discrepency.

The total weight of the plane is 6 lbs 11 oz without fuel. The engine I am using is a SAITO .91.

I am mostly curious due to not wanting to cut the covering to insert the weight. If I need to I will.

Thanks in advance for the help.

AL

Lateral balance is important, especially at the top of a loop or any other inverted flight. Put the 1 oz weight on the wing tip, it is worth it.

While there are many who never check lateral balance I agree with post #2. I always balance my planes laterally and first flights only require a click or two for level flight. A plane that is 1 ounce off will drop the heavy wing as you approach stall speed. Find the most inconspicuous place to cut the covering and add the weight.

That slice you had to make in your beautiful covering job to add the balance weight is worth it. I just hate to do it, but I do.

That becomes a great spot for a stripe or graphic. No one but you will ever know!

Here's why it's important:

If one wing is heavier, the plane will tilt to that side. No problem right? Just drop that aileron a bit and she flies straight.

But now do a loop.

At the top of the loop the plane is inverted, so now the aileron that was dropped, is now raised pushing the already heavy wing down instead of lifting it.

So you will find your plane cork-screwing through loops.

Most guys won't notice a plane being a little out of balance.

However, everything the other guys said is right on. The more acrobatics you do, the more you'll notice it, and the more low speed flight you try, the more you notice it. For joe sport flyer, the most important part is dropping a wing on final approach. A balanced wing will stall off later at a lower speed, even though it's heavier.

My "no measurement" way of balancing a wing is to not worry about it, and go fly. Then, take the plane up high, and do a series of low speed straight ahead stalls. Or, pull full-deflection loops until the plane snaps out. Look to see which way the plane rolls, which wing drops. If it always goes the same way, add weight to the "high wing" until it goes both ways equally, or better yet, stalls straight ahead.

Doing the flight testing will also help you get more familiar with your plane's stall handling, which is a good thing.

It's worth doing.

I added 1/3 oz to my Contender's left wingtip to get lateral balance (two .36 cal lead balls drilled and pinned with "T" pins in line with the plan C.G. outside of the last rib on the tip former, then epoxied in place). I figured that a fully symmetrical low wing with no dihedral would be extremely critical of balance.

If I were in your place I would cut an access hole inside the last rib (on the bottom of the wing) and lash & epoxy a wheel weight to the rib. No point in disturbing that wing-tip covering job.

I bit the bullet and put the weight in. My therapist figures I will be safe to communicate with non RC folks after a few more therapy sessions.

I cut the covering from the bottom of the wing between the last two ribs and 30 min epoxied the weights in place on the last rib. The total weight needed was .9 of an oz.

Thanks again for all of the help. I guess I new it had to be done. Instead of being a Pirate Duck, I was more of a Chicken s**t when it came to cutting into my first covering job.

Twnenty years in the Coast Guard was less stressful than that! :spinnyeye

AL

And you've got nuts in boats like me to thank. My "summer home" is a 34 foot Catalina sailboat. Her name is "Delirious" - more than coincedence?

Bless you and all the Coasties for watching over fools like me.

Thanks Charlie.

I have been retired, well not in the Coast Guard, for 10 years (I had to get a real job) & it is great to hear someone say thanks.

Unless you have lost steerage and the rocks are getting bigger the Coastie's are not appreciated. Fisheries patrol and drug interdiction just seem to p**s people off.

Thanks again.

AL