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Fauvel AV48

Posted: 11 Nov 2018, 08:40
by Sean Fitzgibbon
Hi everyone,
Thought I'd start a thread to detail the progress on my AV48 from the Vic Steele plan and Sarik Hobbies short kit. I started it at the beginning of the year in our Newent and District MAC clubroom, birthplace of the T21 that Frank, Roger and Andy built a few years ago and also the IS-5 canard.
It features an unusual building method, with formers being spaced along top and bottom keel pieces and 1/4 square stringers added to create the initial shape. It's then infilled with 1/4 balsa, sanded and glass clothed.
I'm about three quarters of the way through the infill process at the moment, progress is steady but as we only attend the clubroom two nights a week for a couple of hours, it's not a quick build!

Re: Fauvel AV48

Posted: 11 Nov 2018, 08:43
by Sean Fitzgibbon
Initial framing.

Re: Fauvel AV48

Posted: 11 Nov 2018, 08:45
by Sean Fitzgibbon
3D jigsaw puzzle!

Re: Fauvel AV48

Posted: 25 Dec 2018, 18:03
by Sean Fitzgibbon
Infill process on the fuz finished, the small area at the rear will be done with blue foam. Brought it home from the clubroom to begin the sanding, starting to build the fins next.

Re: Fauvel AV48

Posted: 07 Feb 2019, 21:38
by Sean Fitzgibbon
Building the fins and rudder assemblies to a point where they can be used to figure out attachment points to the inner wing panels, which I'll start next.

Re: Fauvel AV48

Posted: 28 Feb 2019, 21:55
by Sean Fitzgibbon
Nice session in the clubroom tonight. First of the outer panel box spars in it's jig, next session will be installing the incidence tube.

Re: Fauvel AV48

Posted: 21 Mar 2019, 22:24
by Sean Fitzgibbon
Spars are nearly complete, one more to skin and one to make complete, then I can really get to grips with the wing assembly.

Re: Fauvel AV48

Posted: 01 Apr 2019, 21:36
by Sean Fitzgibbon
Spar construction now complete, first wing ribs added to the assembly.

Re: Fauvel AV48

Posted: 25 Apr 2019, 21:47
by Sean Fitzgibbon
So. What I thought would be a straightforward method to assemble the wing,( no clue on the drawing as to how the prototype was built), proved a non starter!
Once the ribs were glued vertically to the main spar, the trailing edge was nowhere near straight.
New plan is to pin the ribs to the board along their goat portion, glue in the upper rear spar to jig them up and then add the main spar. Looks better at the moment, but won't really know until I can lift a complete frame off the board.

Re: Fauvel AV48

Posted: 26 Apr 2019, 11:09
by RobbieB
Sean, to build the wing onto a built up spar is a perfectly acceptable way to do it - the way most full size wooden wings were built; but it has to be done correctly or you will end up with a wavy wing as you have done. You cannot rely on the mating faces of the ribs all being correct, even laser cut ply. Even a very small difference in angle there will result in a significant change at the trailing edge.

The correct way is to add the root rib followed by the last rib before any change in wing taper and/or start of change in section. You then need to add a thread datum stretched between the two and this acts as the reference for all the other ribs in between - it is very accurate. You will, of course, probably have to modify the front mating face of many, if not all of the other ribs so as to locate them accurately. I do this by carefully wiping them across a piece of sandpaper until they locate - most only requiring one or two wipes, in balsa, anyway.

You then do the same with the remaining ribs out to the tip.

The leading edge ribs are done in a similar fashion, the only difference here is you leave the spruce false LE cut-out in place with a central line marked on it as the guide for cotton thread. Once all the LE ribs and sub ribs are in place these can be removed and the false spruce LE added before the spar is turned over.

IMG_0011_1.jpg
IMG_0001 (2).jpg

Both LE and TE ribs are held in position when ready and secured with a drop of watery cyno - instant adhesion (as are the fingers on occasions!)