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Kyri

F3F repairs

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Kyri

Here it is with the masking removed, it isn't completely perfect, close up the repaired nose is not totally smooth, but not bad, I am happy with it. I fear that the paint will come off eventually, I could consider a clear coat over the top I suppose, but probably won't bother.

!new nose with hatch.JPG

!new nise close.JPG

!new nose painted.JPG

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oipigface

Photos at last:

915CF861-6B4F-4F39-8C68-71368DDCF404.thumb.jpeg.f92e35b3b544719a2d2a7fa8bf44583f.jpeg

Pushrods sheathed in split heatshrink.

4A5CBDF5-F783-48C5-B238-F95E136E6AB2.thumb.jpeg.1dc7f708fc09c49b173d4c16e5b3ae46.jpeg

Pushrods sheathed in split heat shrink and wrapped in plastic sheet. Note bulkhead on the right. I also brushed a little R5 onto the pushrods where they go through the bulkhead, just in case any glue found its way past the edge of the plastic.

76B323EE-A065-4254-AAC5-843AF3AFD8F9.thumb.jpeg.9503959111ab47c73f1d51b0101f8932.jpeg

Card from Waitrose Wheat and Rice Flakes box cut about 1/4” larger than window all round, and shaped on the right to fit over bulkhead.  Kevlar tape under.

799BB460-19AD-45BF-8AC4-5074A729A9CA.thumb.jpeg.bccdfd6050e4dc3b2860635683a38cf3.jpeg

Top side with holes pierced for string.

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Fit in place.

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Left hand piece of tape applies pressure to bukhead. Right hand secures tensioned string.

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Four of these were just enough to fill the cavity. I did think of putting some tows across the whole lot, and then thought better of it. I’ll know  that I should have if it goes again. I’ll post a picture of the finished job when I’ve finished it.

 

 

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Kyri

Looks good, and its great that it didn't break totally so your incidence is not affected although those pushrods are a pain making your job much more difficult! Since the area will be in tension as well as compression you may be able to add reinforcement to the outside, but as you say it might be ok and can always be done in future. 

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isoaritfirst

Lovely innovation John. 

years ago I filled a fuselage with lead shot to add weight to an inner cloth that I couldn’t get too  

 

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oipigface
28 minutes ago, isoaritfirst said:

Lovely innovation John. 

years ago I filled a fuselage with lead shot to add weight to an inner cloth that I couldn’t get too  

 

I hadn’t thought of that, but I will remember it!

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Kyri

Now for the servo tray. As it turns out, I didn't have to make one, because the servos, inner pushrods and tray were salvaged from another crashed plane. Due to that one having a repair behind the back of the wing, I didn't save the pushrod outers, and had decided to put some suitable servos in the tail. As a result I could use those spare parts in this repair.

(I put a tray that I made in the other model to strengthen the nose, can get a picture of it maybe later)

Here is the newly fixed front end with the tray fitted, and glued very well with 24hr araldite, my favourite for this type of thing. The kevlar was scuffed up a bit first and it is a reasonably tight fit with excess glue which flows in to a nice rounded bead as is slow setting. I will glue the pushrods to the side of the fuz later. 

 

 

!new nose servos.JPG

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Kyri

Now for the next challenge, some missing wiper...

 

wiper1.JPG

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Kyri

Preparing the area, to make sure sticky stuff only goes where it is supposed to:

 

wing2.JPG

3wing.JPG

4wing.JPG

5wing.JPG

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Kyri

Now for the shaping of the mould for the new wiper. I chose to put thick tape stuck to the moving surface, (which will be held back) and the tape due to its thickness and stiffness should bend into a curve very similar to the original wiper. The prepwork is to prevent a permanently deflected surface!

This is the tape, which is not stuck down yet because the wiper mix needs to be applied. 

For the mix I deliberated over 24hr araldite, or this laminating epoxy which is faster setting but likely to be more brittle. I went for the fast setting option. The filler is microballoons. Other options considered were chopped glass reinforced epoxy or some way of putting glass cloth within the wiper to strengthen it. Since this is an aileron then the wiper will never be fully exposed so I didn't complicate things too much.

The orange putty type material is silicone which can be moulded by hand and not much sticks to it. Plasticine or blue tak or similar could have been used for this.

 

 

7wing.JPG

8wing.JPG

9wing.JPG

10wing.JPG

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Kyri

The mix is made, and applied to the area. The wing will need to be held in a position to allow the mix to settle in the "right" position. This was not an easy thing to do and I made an arrangement which lightly clamps one end and supports the other. I didn't clamp it too hard so the joiner is not getting hurt in this experiment😉 it is actually the the remains of a broken one.

The aileron is held in the deflected position, as the new wiper cures.

11wing.JPG

12wing.JPG

13wing.JPG

14wing.JPG

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Kyri

First look at the new wiper, it looks like a nice join to the original, with a slight colour difference (concentration of microballoons or maybe the original had a different formulation?)

 

 

15wing.JPG

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Kyri

The wiper seems to be the right shape, no binding, I sanded the edge a little. Fortunately, this wiper will never be full exposed due the limited down travel of the ailerons. 

 

16wing.JPG

17wing.JPG

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Kyri

Tidying up of the bits on each side, and a fill/strengthening of the edge of the flap. Back up side down for a while to cure!

 

18wing.JPG

19wing.JPG

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satinet

You can actually repair the wipers a bit more simply than that. If you get some tape that will follow the curvature you need (i.e a tape that's not too floppy. You can just attach a line of tape to the aileron/flap and wipe your ******* up to that. 

 

https://photos.app.goo.gl/SXgNBYejG92nscuJ8

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isoaritfirst

That worked for me using Diamond tape. 

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pete beadle

Hi all

Worked for me too - but using greenhouse repair tape

Regards

Pete

BARCS1702

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Kyri

Tom, good pics, looks like it is simple enough to do! Will note for next time. And all sorts of tape work by the sounds of things, great! I must get some more diamond tape (ran out) and greenhouse tape, I will find out what that is, it sounds interesting. 

In the meantime here is the area after removing the tape.

20wing.JPG

21wing.JPG

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satinet

There is a video of an Australian guy doing the wipers on a new model. On you tube somewhere.

It's just a question of mixing the right consistency of epoxy/balloons/thicker. I put it in with a metal ruler iirc.

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satinet

Looks like it. 

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