Aileron rebuild question

[mhorowit]

After gluing the thin plywood plates on the doubler plates, varnishing everything (except where the other plywood plates will go), I tried to slip the two ribs that mount in on the doubler into place; sort of like making engine noises while sitting in the cockpit.

They didn't fit.

The new combo of spar and doubler plate is 11/64th thicker than the old combo.

Has anyone else had this happen?

I've stepped away from the aileron and am taking deep breaths. I think I'll be OK in about an hour.

How did this happen? Can I recover from this by widening the slot in the rib?

MikeH (taking deep breaths)

[Robert Lees]

Re: Aileron rebuild question

Mike , send your ailerons to me. I'll fix them free of charge. It'll make a change from all the strut postings




Seriously, post (or email me) photos of your aileron issues...if you can't slide the ribs over the ply plates, just tweak the ali flanges a bit if you can.

If the flanges won't tweak, open them a bit (do you remember this sort of conversation from your young teen years in the 60's, but on a different subject?) which may involve rounding the internal corners with a file or similar. The ribs will all be the same once you use your hammer to pound the nails in. Careful now!

Remember, a photo says a thousand words....ooops! back in the 60's again!

[Forrest Barber]

Re: Aileron rebuild question

OR visit Alliance , I have about 25 ailerons , surely most are better than yours!

[mhorowit]

Re: Aileron rebuild question

Seriously, post (or email me) photos of your aileron issues...if you can't slide the ribs over the ply plates, just tweak the ali flanges a bit if you can.

Rob

Here are some pics. First is a shot of my recently completed spar. The spar is 32/64ths and the reinforcement is also 32/64ths making a total thickness of 64/64ths.

Second shot is of one of the ribs showing an opening of 57/64ths

Finally, a shot of the original spar with the spar being 30/64 and the reinforcement 24/64ths for a total thickness of 54/64ths.

Apparently the reinforcement plates aren't the same thickness as the spars

Although adjusting the rib slot is attractive, that would seem a more weakening change to the overall structure than planing/sanding the reinforcement plate down so the ribs will slide on.

Suggestions? - MikeH

[Robert Lees]

Re: Aileron rebuild question

Why is your new spar constructed thicker than the old one?

Looks like you need to plane it down to match the dimensions of the original.

[mhorowit]

Re: Aileron rebuild question

Why is your new spar constructed thicker than the old one?

Looks like you need to plane it down to match the dimensions of the original.

Good morning Rob -
That indeed is the question!
I used the same material I used for the reinforcing plate that I did for the spar;
I'll start the planing process this morning.
Did you have to plane down your spar stock to build the plate? - MikeH

[Robert Lees]

Re: Aileron rebuild question

No, I bought the correct thickness from Aircraft Spruce. I used the drawings on Ron Greene's CD (and my original spars) as reference.

Good luck with the planing (and re-varnishing).

Rob

[mhorowit]

Re: Aileron rebuild question

No, I bought the correct thickness from Aircraft Spruce. I used the drawings on Ron Greene's CD (and my original spars) as reference.

Good luck with the planing (and re-varnishing).

Rob

It's coming along well. Jack plane to close to the correct size and orbital sander after noon tomorrow (some neighbors might not appreciate the noise at 0700 - I just don't understand! - MikeH

I looked in Green's collection and went thru the section on ailerons, without seeing mention of the reinforcement plate; do you recall the drawing number?

[stormman]

Re: Aileron rebuild question

Its been my experience that A/C spruce send the spars oversize and lets you plane them down at your local cabinet shop. Use a Micrometer on them

[mhorowit]

Re: Aileron rebuild question

Why is your new spar constructed thicker than the old one?

Looks like you need to plane it down to match the dimensions of the original.

Rob - I've planed down the spar so that the rib just fits over the spar/plate combo in the center of the spar. How much did you allow for the thickness of the varnish coats? - MikeH

[Robert Lees]

Re: Aileron rebuild question

About one thou (one mil in old US-speak).

Rob