Aileron Balance Weights

[Micro Mong Bldr]

My model 2 has the balance weights at the ends of the ailerons. I notice h newer ones are located nearer the center of the ailerons. It seems to me that this would be better for flutter resistance (half length is stiffer). Is it worth changing?

[jiott]

The model 7 SS has balance weights at BOTH mid and ends.

[DesertFox4]

Micro- my model 3 had the single weights out on the end and had no ill effects.
When I built my model 4, I used the single weight on the end of the flapperons and have been to vne many times with no problems. I've flown basic aerobatics with it also. The Speedsters had the two smaller weights and one was about 50 % and the other near the end. Their mass ( weight ) added up to the single counter balance weights.

You should be fine. Most early Kitfoxs have your set up.

[Micro Mong Bldr]

Thanks! :)

[bradrau]

How critical is the location of the inboard Mass Weight? Can it be moved in or out an inch or two? Mine just happens to line up with a rivet installed in the aft edge of the flaperon.

[PapuaPilot]

You better check with the factory about moving it. But I don't think it would matter where they are installed, unless there is harmonic flexing that could happen along the length of the flaperon. The purpose its to balance the flaperon on the hinge point.

Would it be possible for you to remove the rivet and use the existing hole to mount the balance weight, that is to go through the skins and counter weight? Another option might be to install a countersunk rivet so it doesn't interfere with the balance weight.

[kitfoxnick]

Don't forget to consider a possible interference when the wings are folded back. The flapperons are vertical and the mass balance weights need to be offset so that they don't hit when back to back.

[Esser]

I just had this issue. Factory said try to use the same hole (which I couldn't) but if I had to, move them. I moved them a half inch out board.

Anyone doing this step soon, drill your flapperon trailing edge after.

[jrevens]

...
Would it be possible for you to remove the rivet and use the existing hole to mount the balance weight, that is to go through the skins and counter weight? ...

That's what I ended up doing on one of mine... wasn't thinking ahead. Just as an educated guess, I don't think you'd want to move them too far as it seems like they are positioned over internal foam ribs if they are placed where the instructions say to do it. If necessary I think you could drill out the rivet you have already installed, fill the hole with Hysol, let it cure, then drill another hole to line up with the existing holes in the counterweight assembly. Even if the old hole is very close to where you want your new hole, there is probably no harm in doing that. Keep in mind that you would still have 2 really "good" holes (they'd all look "good"). Also consider that the weight assemblies were only attached with rivets on the earlier models (at least on the mod. IVs I've seen) and yours will also be bonded to the flaperon (I'm assuming you're building a 7 SS). I think it's best to have those weights directly over the ribs, but I'm not sure how critical it is. These are just my personal opinions & thoughts, & you can use them at your own risk.

[Jerrytex]

On my KF 5 project, the original manual said the outer mass weight is set at 3" from outer hinge. The new kitfox build manual has it at 6 1/4". Anyone know the reasoning? Any reason to not put it at the newer measurement?

Also, the original build manual has the flaperon control arm set at 5 1/4" from the end flaperon hinge. The new manual has it at 4 3/4". Any reason to not use the newer measurement? The original manual shows the use of a flaperon bearing, but I understand that this has been eliminated on the newer kits and I wasn't planning on using it.

[henrysamson]

Many years ago when I was building my model 4 I folded my wings with the weights held in place with clecos. I discovered that they would not fold completely as the two inboard weights contacted each other. I contacted support and they said just move one of them far enough that they don't conflict. So I did that and filled the holes on one of the flaperons. So, perhaps the position is not that critical. This was in the late 90's with a model 4 Speedster. Two weights on each flaperon.

[khalillm]

Hi friend... Anybody know which is the weight of each balancer??

[Eric Page]

Mine (for a 1995 Series 5) weigh:

693.0 g
708.6 g
709.7 g
711.1 g