Improved Aileron Bushes

[dan tonner]

"...……………..really you need 2 bushes per hangar one either side to balance the load better...………."

 

Can you elaborate a little here Mark?

 

 

[Kyle Communications]

I am thinking more like this...I will make a few dummy versions up and see. This way the load on the hangar bracket and "slip" for the bearing material should be the same

 

Sorry it was a quick scribble to show what I am thinking

 

 

 

[dan tonner]

Thanks Mark - I like the way you think.

 

Given that the brackets are only about 1/8" thick, the "nose portion" of the bushing will demand some pretty close tolerances; too short and both brackets get locked against the bushings; too long - and the "free" bracket loses lateral support.

 

I spent some time in the hangar yesterday and made note of the following:

 

1. The "stock" bolt holes in my moving and stationary brackets are 6mm; an AN4 bolt is 6.34mm and could be accommodated by either bracket;

 

2. the stationary brackets (on the wing) are flat pieces of stock, easily accessed and can accommodate a 3/8" (9.53 mm) hole for the flanged bushing(s). (The stubby aileron bracket provides less room to drill "square" and is angled stock.)

 

4. My inclination would be to secure the bushings to the aileron brackets (AN4 bolt) and allow the fixed bushings to turn inside the enlarged holes in the stationary brackets on the wing.

 

3. A flanged Nylon, Teflon or suitable Plastic (?) bushing with an OD of 9.53 mm, and ID of 6.34mm turned from 12 mm round rod stock would still have more than 1.5 mm of "wear thickness" surrounding the AN4 (1/4") support bolt.

 

While at the hangar I reversed the assembly direction of the stock brass bushing in my "loose" aileron.. That eliminated nearly all the slop in the outer right flaperon attachment - although I realize it will be short lived. My calipers showed the original bushing is now narrower at the unflanged end (where the aileron bracket was initially supported).

 

BOB: I thought you might be interested in the attached page from my assembly manual - it would seem the insertion direction of the AN3 bolt (and consequently, the orientation of the flanged bushing) was at the discretion (whim?) of the assembly manual writer. The pictures from your manual are not present in my manual and the attached page seems to imply that the bolts lace through the aileron attachment first at each support. My manual also seems to show unflanged bushings although my kit came with the flanged ones. Gotta love that manual!

 

CanadaDan

 

aileron attachment.docx

 

aileron attachment.docx

[IBob]

Hi Dan. It's evident that ICP have made some changes along the way to this part of the build, presumably to overcome the problem of wear.

 

Below is a pic of the instructions that go with the pic 17 & 18 of the assemblies (which I posted previously):

 

Place bolt with a lot of grease like picture 17 & 18 (toward of bolt : from outer to inner)

 

I read this as direction of bolt from outer wing towards fuselage, which is what the pics show

 

use 1 bolt AN3-05, 1 washer AN4 between wing clamp and aileron clamp, 1 bush SC210 (from inner to outer)

 

so the bush is inserted from the fuselage side

 

castle nut and cotter pin (close the bolts, the aileron is free to move).

 

I assume this means tighten the bolt, but leaving the aileron free to move.

 

As per the sketch, all my brackets (which have paint on) measure approx. 2.5mm in thickness. The washer is 1.5mm. And the bush is 6.5mm.

 

It looks to me as though the intention is to be able to tighten the bolt down more or less fully on the bush.

 

I should have masked those pivot points, I may have to remove the paint...(

 

 

 

 

 

[facthunter]

If you don't tighten till the bush is held firmly the whole design is compromised. Nev

 

 

[IBob]

If you don't tighten till the bush is held firmly the whole design is compromised. Nev

The dimension I could/should have added is that is a 6mm bush going through all 6mm holes....rather than being clamped to hanger or aileron bracket as per JG's mod. So there's still nothing to prevent the thing tilting but the relative tightness of the whole sandwich...which is less than ideal

 

 

[IBob]

So, for my money, it looks like the best option is an upsized version of JG's mod. And probably clamped to the ailerons/rotating in the hangers , due to the relative accessibility of those 2parts ( it will be much easire to drill out the hangers to bush size), as pointed out by Dan.

 

 

[facthunter]

Pulling a flanged bush up against the face of the support with say a 1/4 bolt is quite satisfactory. The other element Nylon etc moves on the clamped bush with some end clearance existing when tight. It could be in two halves as Kyles is . ALL control hinges need to be relatively play free during their life.. If the bolt is not tight against a fixed size the whole thing can tilt in the hole, which is all over the place from a design point of view.. There are better design possibliities from a weight/strength point of view but simplicity has a strong argument, in any evaluation of a design. Nev