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oipigface

How to unplug sticky wings?

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satinet

Well it's certainly been one of the most interesting threads for a while.

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Kyri
On 10/11/2018 at 17:43, oipigface said:

 You wouldn't expect after that amount of time that there would be much left of it, but the wings and the fuselage seem at first sight to be in quite good nick. The boom is broken, and there's a tear in the starboard wing LE, but the structure seems fine. I haven't checked the servos yet, and the tailplanes are a different matter. I suspect that they would be OK to fly again, but the skin has sagged around the substructure, so the section is very far from accurate.

Excellent work to get the wings apart!!

What is the structure like after being by the radiator for a while, any better? What will be involved to get this flying again, are the tailplanes repairable?

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pete beadle

Hi OPF

Personally I think your thread is a great incentive to others to NOT throw the bits in the bin before you've assessed if a repair and refurb IS possible

As Skip would (probably) say "Good on yer Mate!"

So, well done and well described, I'm sure it will encourage others to at least TRY a repair instead of just binning the broken bits of  the plane!:thumbsup::yes::)

Regards

Pete

BARCS1702

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Phil.Taylor

Well done John ! - perseverance pays off

hope it will soon be back in the air

Phil.

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isoaritfirst

Only ever binned one model.

a McMeekin DS Falcon. 

180 mph straight into the trunk of a very large oak tree. 

Dug a hole and buried it where it lay. 

 

 

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oipigface

Spent most of my aeroplane time today cleaning up the Extreme, assessing the damage and what I’m going to do about it. The fuselage is snapped about half way between wing and tail. The break is not clean, though, because the boom is built with a quite heavy carbon/kevlar cloth and kevlar doesn’t get brittle the way carbon does when it is used with epoxy. 

 

566F2363-24C1-4984-B773-53C64BAB5C67.thumb.jpeg.bd05907dad1c3e48cbb730b352e89cad.jpeg

I am thinking that a carbon/ epoxy tube inserted in there is probably the way to go. Although the plane generally seems to be in really good nick, there are places where more damp may have got in than others, and this break in the fus is one of them. I’m thinking maybe 2.5 or 3 inches of carbon on each side. I’ve taken the pushrods and their outers out, so there are no difficulties in putting stuff inside. 

DB9ABF51-2E50-4C6E-B238-863746571D72.thumb.jpeg.71d08fc0988babb248084698d8281ef3.jpeg

Here’s the hole in the wing. It’s about 4 inches across, and in a part of the wing where the LE and TE are parallel, so I’m probably going to take a mould from the opposite wing, to make a new bit of wingskin with.

The rest of the damage is really quite minor. I’ve lost the covers for the wing pushrods, and there’s some algae growing on the wipers:

122EEC33-60E5-4432-8122-9FDF6A0CF3C6.thumb.jpeg.e8c7f151feeaa9e401c1baadaf6d99fa.jpeg

There’s a small ding in the wing skin:

ECF10260-4FD2-45FC-8AF7-51BDACD9EC60.thumb.jpeg.413c0c5bfc41664d615585890cd08bff.jpeg

and a very small crease and a bit of distortion of the aileron on one wingtip:

C7CDF551-772B-4778-9129-1E5CEC91138F.thumb.jpeg.d5ecfc28482384e3b3992bb057527768.jpeg

I think the tailplanes can only be discarded. The foam stuff used for the skins has completely collapsed, and I’ve ordered a new set:

748400A1-5ADD-480B-9954-02418F52889E.thumb.jpeg.b750da9550cdd8fe0c1b5d036e005618.jpeg

 

I’m looking forward to flying it again, but I don’t think I shall ever try to race it. Even though it seems as robust as it always was, I’m not at all sure that seven years in the damp can leave a composite structure like this unscathed.

 

AA1E211B-A0CC-4782-ABFA-D45D2EC99EFB.jpeg

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Witch_1

With new tails, and a repaired fus, the main concern would be for the aileron/flap skins to delaminate and flutter (try tapping etc), or for the shear web of the spars to weaken as these may include balsa which might have suffered.  In my Crossfire the shear web is balsa only (I have had opportunity to inspect this...).  The published details on Shinto show a similar sort of approach.

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Phil.Taylor

Fix it up - then it's...

"Run Forrest Run!" 😁

 

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wookman

Well done OPF. Perseverance pays off. With your skills that looks very repairable. With that amazing colour scheme it really deserves to back in the air. What history and provenance.

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isoaritfirst

Flooding the te sparwith cyano may restore some structure if you think

it has deteriorated. 

But you can get products for repairing damp wood. 

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Ridgerage

Hi

If you decide to reinforce any potentially rotted or moisture damaged timber I've found Rustins wood hardener to be best, I've used it many times in my job and it has migrated over to the hobby aswell. 

It really does work well and makes the balsa rock hard, it can be thinned with white spirit to allow it to be run down the spar/sheer web. 

If you do use it be careful to avoid surface contamination as it dries quickly, especially when thinned for some reason, and is a pain to remove when set. 

It's also good for stabilising balsa prior to sanding a bit like sanding sealer but much tougher, ideal for leading edges. 

Regard Gareth 

Good luck with whatever you do, this has been a great thread👍

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Scram

Quote   "  I’m not at all sure that seven years in the damp can leave a composite structure like this unscathed. "

Wonder how all those McClaren's etc get on then, specially with a bit of salt thrown in  :frantics:  🤔

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oipigface
1 hour ago, Scram said:

Wonder how all those McClaren's etc get on then, specially with a bit of salt thrown in  :frantics:  🤔

Being in a Welsh forest, in whatever weather happens to happen is a bit different from being kept in a nice warm garage with an occasional outing in the wet! It’s actually the possibility that part of the structure might be wood that worries me most. I doubt if there are many Morgans that aren’t kept under cover.

I have only come across one piece of wood in the model. This was an insert to the servo tray, which fell apart as soon as I started to remove the servos. If there is any wood in the wings, I really wouldn’t want to stress it too much, if at all. I’ll ask Milan.

Speaking of servos, I found three Futaba S3150’s labelled ‘gears’ in a box today, and another labelled ‘gears fitted August 2018’. I think these are probably what I’ll fit.

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Kyri

I repaired a rotmilan, and I didn't see any wood in the wing structure apart from the spars encased in glass so possibly ok,  but better to check with Milan. I saw what looks like a foamed acrylic (rohacell?) with a layer of glass on the inside of the skins. Can you get an inspection tool camera that you can put inside one of the servo hatches to have a look?

 

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Kyri

I will dig out some pics of the one I had apart so you can see it later.

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Kyri

It is possible that the end grain balsa used in the spars, could lose some of its compressive strength if wet. However it appears to be well contained in glass and resin, so I am not sure how you could check this. One way could be to try to compress the spars at various places. It is likely that the carbon top and bottom is strong enough, but if the balsa separating them was to collapse it could be an issue. I know someone who got into making their own moulded planes some years ago and learnt the hard way that there is a reason why end grain balsa is used even though it is more time consuming to cut to size and prepare... 

Here are some pics. Unfortunately I didn't take too many pics of this, but I have a few if its of any help (and assuming he used the same construction for both models)

 

 

rotmilan1.JPG

rotmilan2.JPG

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Brett82
2 hours ago, Kyri said:

Can you get an inspection tool camera that you can put inside one of the servo hatches to have a look?

Just as an FYI... Lidl have inspection cameras for sale and don't cost an arm and a leg.

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f3fman
14 minutes ago, Brett82 said:

Just as an FYI... Lidl have inspection cameras for sale and don't cost an arm and a leg.

Give us a clue how much less than an arm and a leg they cost ?

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Kyri

I got one, a while back, here is a pic of the inside of that needle wing being repaired, I wanted to check the spar and rib, I need to update that other thread with it but this pic will give you an idea of what you can see. It is a "powerfix profi inspection camera". 

 

lidl cam.JPG

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Brett82
11 minutes ago, f3fman said:

Give us a clue how much less than an arm and a leg they cost ?

50 quid, so maybe a big toe...

https://www.lidl.co.uk/en/MiddleofLidl.htm?articleId=20299

They also have the air bag wedges Scram mentioned earlier in the thread. 2x for 7 quid.

https://www.lidl.co.uk/en/MiddleofLidl.htm?articleId=19989

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