Aileron Balance Tube - a few more pointers?

[James]

Hi Guys,

sorry I've been a bit quiet on the forums lately - I've been building up the second wing like the first, and so there's been less "uncharted" territory to navigate.

I've google searched this a bit, but can anyone help me with my aileron balance tubes?

1) I have 1" holes in the aileron nose ribs, but I inherited a 3/4" tube full of melted lead ready to drill out. Do you just pop rivet this smaller tube on two sides (seems dodgy), or do I make a supporting doubler at each rib, or do I just recast the whole tube at 1" diameter?

2) There seems to be confusion as to whether you extend the whole tube past the inboard hinge, or should I cut it into two sections? I don't think I can make the weight requirements if I shorten the tube to match the ribs between the two hinges.

Let me know guys, and I'll add the answers to Jared's extremely helpful beartips page.

Thanks in advance,

James

[jaredyates]

I think you want to recast into a 1" tube and can't imagine you'll have any trouble making the weight. Mine were not full at all. There is much more volume in the 1" tube.

[robcaldwell]

I've been reading on this subject as I am approaching the aileron portion of my build as well. Bearhawk.tips, Beartracks, the manuals all provide great details on loading the tubes with weight. And when finished with that task, end with "slide in place and pop rivet with stainless rivets". I am unclear as what and where I am pop riveting. I assume I am taking a small piece of .025 aluminum and riveting to the ribs to serve as a cap? Anyone have a picture of this? Thanks!

[Mark Goldberg]

Rob, the size of the hole for the counterweight present in the leading edge of the aileron has changed over the years. So make sure what size aluminum tube you need. I suspect you need 7/8". After filling the long tube and inserting it - drill some holes into the counterweight tube from the outside in each aileron nose rib. Stainless pops are OK and I have used sheet metal screws also. You want to secure the counterweight tube well so it will not become loose over time. And do not use a fastener with a large protruding head as the aileron nose has to clear the trailing edge of the wing as it moves. Mark

[James]

Thanks for all the help guys :-)

Mark - when you mention clearance of the fastener head to the trailing edge, I have another question for this area: there's a "step" in the trailing edge, which accommodates the different chord lengths of the aileron and the flap. Setting up the flap hinges to have an even span-wise gap, the inboard edge of the flap ended up close to this step, about 1/16". Do I need to ease this back to 3/16" or 1/4" like the clearance for the trailing edge? The only time it will touch is if the flap hinges float axially.

Or is this not worth worrying about?

James

[marcusofcotton]

Rob,
The holes for the weighted tube are at the very front of the aileron nose rib such that 2 rivets will be through the skin and the rib flange at each rib. One from the bottom and one from the front. No end caps used.

[johwiltb]

... Anyone have a picture of this? Thanks!

Recognizing that this may already be apparent, if you're a visual person like me, here's the reference for attachment in the plan. The orange arrows point to the rivets, and I believe they are in every rib. This *is* the Model B plans, not sure if it's different on the A. And I imagine the beartracks tips show how to cap the tube.
IMG_6452[31599].jpg

[robcaldwell]

Excellent!

[robcaldwell]

Thanks guys!

[Bcone1381]

On the topic of weight, I want the weight to be adjustable, that way after covering the aileron, I can remove unnecessary weight.

It was an educational experience getting lead to melt into a 4' long aluminum tube that I had on hand. I ended up with a steel tube about 12 inches long split down the middle that had a similar ID as the aluminum 7/8" tube. I clamped the 12 inch tube with hose clamps, sealed the seam with drywall joint compound, then poured lead into the tube. I can adjust each of them in the future by shortening the lead cylinder as needed.

[SimonNicholson]

The final weight of my balance tubes were 2340g. I am using Oratex which is 140g/m. I riveted them in with 1/8 s/s pop rivets which were covered in an anti galling compound. The tubes are 3/4” and neatly slide into the factory drilled holes.

I have since covered my ailerons and they are perfectly balanced.

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