How to set incidence pins in foamies

[Happy Days]

Here’s my problem….

I’m Building a foamie.
With a 2 piece wing.

This is the side of the fuse.....You can se the carbon tube for the wing joiner to pass through. (And a wooden longeron for rigidity)

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Next is the edge of the wing root,..........just in case you didn't know what you were looking at. :roll:

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How can I fix the incidence pin into the fuse? and the socket for the pin to fit into in the wing root without risking, over time,  the pin, or it’s socket, becoming loose in the foam and allowing the angle of the wing to change?

Nice simple question, who has a nice simple answer for me?

K.

[Fred]

Hi Keith,

Not too sure what you mean :?:
But you just have to insert a tube in the foam, where the incidence pin and the wing joiner goes.

[Aidan]

Fred can probably contribute more experience and tell you if this is necessary but I'd be inclined to insert a small balsa block or a disc of plywood into the fuselage and wing root and then fit the pin and socket to these rather than directly to the foam. This will spread the load and should make the pins far more secure and durable. You could also run the tube in the fuselage right through like the joiner tube for a little extra support if you wanted.

Aidan

[Happy Days]

Thanks for your comments Fred…..I think the problem I’m talking about is getting lost in words. I’m not being very articulate today. :roll:

Aidan…..You seem to have grasped what I was thinking about.  I take your point. A piece of wooden doweling right through the fuse, with a small piece set into the wing root would probably make a nice secure fixing.
Thanks for your idea. :clap:

Keith

[Fred]

The problem I see with the wood, and with this type of gliders, is that the hole in the wood might get enlarged (if you see what I mean), although the EPP might get destroyed before that, but small repetitives impacts, like at landings, may accelerate the process.
If you use an Aluminium tube, or carbone tube, that will not happen.

Another way, would be to drill a hole is the EPP, twice the diametre you need, fill with epoxy, and drill your hole for the pin, but I'm lazy, so I'll still go for the tube  

Like this, tube epoxied directly in the foam.

[Happy Days]

Thanks for your response Fred.

Er,…….not quite sure we are talking about the same thing. :?:

In your picture it looks to me as thought you are talking about the socket for the wing joiner. My wing joiner is fitted in place with Polyurethane glue.

I’m talking about fitting the incidence pin.

I understand your point about the hole becoming enlarged…..that’s why I didn’t want to put the pin straight into the EPP.

Keith

[Fred]

Hi Keith,

No, that was to illustrate what I was saying  #-o
You are talking about the incidence pin in the wing so right ?  :?:
Easiest/cleanest, because your wing is already taped / covered, would be to glue a rib at the root, 3mm plywood, or 1.5mm epoxy, drill a hole the diameter of the pin, and glue everything there with epoxy.

Fred - Lost in translation  :mrgreen:

[Happy Days]

HHHMMmmmmmmmmm :?: ………………….That might work!

Yes, I think I’ll use both ideas.  I’ll glue a piece of dowel through the fuse to set the incidence pin into, and then epoxy a rib to the root of each wing half and drill a hole for the pin to locate into.

Sorted!

Thanks guys.

K.