Scale Soaring UK

As I have little else to do at the moment I have been spending my time going over my fleet of models and giving them their annual MOT. While checking out my 13 year old 1:3.5 Oly 463 I became rather concerned with the amount of slop movement on the ailerons. The Oly has ‘Freise’ ailerons which were never absolutely solid but have become worse as the years have gone by. I did received a bit of a warning last year when I put the model into a dive for a loop and one, or both, ailerons gave me a vocal warning that they were unhappy and that I should slow up a bit.

The horns are made from 2mm epoxy board and are an integral part of the aileron structure. When I wiggled the aileron I could see the clevis moving slightly in relation to the horn. On unfastening the clevis the hole in the horn looked slightly oval.

I now have the problem of how to remove the slop from the system. I cannot remove the aileron from the wing as the aileron pivots are built into the wing structure and totally inaccessible. I cannot remove the horn from the aileron as it is also built into the structure and fairly inaccessible.

Can anyone suggest a simple solution or quick fix?

HELLLLLP, Brian.

Can you bond in a small piece of brass tube, suitably sized for your clevise?

Simon

Partially fill the hole in the horn with epoxy or thick cyano, and re-ream it?

I had thought of 'bushing' the hole Simon but it would be very tricky with my sausage fingers.

I had also thought of filling and re-drilling but there is not a straight access to the hole with a drill Trevor.
Brian

Brian, could you not bond a new piece of pcb onto the original having first drilled a 1.6 hole in it, you could even bush the new part first that should prevent any more wear in the future, i know its a fiddle, thats the only way i can see getting in.

A trick with DLG models is to fill the hole in the horn with thick superglue and connect a clevis. When the superglue has dried rotate the clevis so as to rotate the clvis pin in the hole.
The glue fileed jole will now be the correct size for the clevis pin!

Martin

Brian, a drop of cyano certainly does the job.
I was quite sceptical and concerned that everything would lock solid but just rotate with some pressure and it will free up.
Paul

Brian there are on the market larger clevises with larger pins. You could buy the next size up and then ream out the hole in the horn with a home made reamer made from an old drill and fit the new clevis. Always providing you can get to the clevis and actuating rod to replace them.

Brian, I would go for the brass bushing of the aileron horn. I have used this used this method on a 5m ASW15 rudder with great success and on larger models. Regards John.

Brian

I have had good success with the cyno method as mentioned above. I use Zap a Gap (the green labeled bottle). I do spray the clevis with WD40 first as a precaution against it sticking but it works very well. Just put a drop in the hole and then clip a clevis in. I suggest you use a spare clevis and not the one on your pushrod to enable you to wiggle it easier once the glue has set. do not use any accelerator to speed up the process and do leave it several minutes for the cyno to set hard. The horn will not be very porous and so the cyno will take time to properly harden. Removing the clevis too soon will make for a poor job.

AEB

Right gents – the results!.

I inserted thick slow set cyano in each side of the horn hole and attached a new clevis to the horn. I had taken the additional precaution of squirting the clevis with household furniture polish. This was allowed to set for about an hour and a half. When I returned to the wing the clevis broke away readily and I refitted the clevis attached to the pushrod. There was appreciable less slop in the aileron but the clevis appeared to be solid on the horn with no movement showing.
I did noticed that there was a little rocking movement where the clevis was screwed onto the pushrod so I applied a drop of cyano there as well. When this had set I waggled the aileron once more and although there is still a very slight movement it is restricted to just under 1mm rather than the original 5 or 6mm.
I regard this as a definite success The second wing is now sitting with its horn being glued up at the moment.

Thank you once again for your help and opinions gents – I has been much appreciated.

Brian.

B Sharp wrote: ↑12 Jan 2021, 12:26 Right gents – the results!.

'.............I did noticed that there was a little rocking movement where the clevis was screwed onto the pushrod so I applied a drop of cyano there as well.......'

Brian.

Brian, do you not use lock nuts on the pushrod behind the clevis?

Yes, I usually do Robbie, however the clevises have been adjusted several times over the lifetime of the model and the locknuts are now loose. The pushrods come through a small hole and the nuts are inaccessible to tighten them up.
Brian.