Begin' Acro Glider

Chris - One solution, get some sheet balsa, same grade & thickness, cut the " teeth" away
on both sheets. Replace these with a single sheet & butt joint the 3 together.
Protect building board , run bead of glue along one edge, pin to board & then lay next sheet
Alongside forming tight joint & pin to board. Repeat with last sheet.
Hope this helps.
Colin.

I don't think a jig is required.... I would imagine that if they overlay each other or join together, this is to increase the joined length for glueing or strength.

If butt jointing, lay in position, run masking tape over joint. Then fold back and apply glue, laying flat again. Should keep sanding to a min.

Stuart

Thanks for the tips, I feel coming into the hobby now, in the age of the ARTF, that I've missed a lot of the building knowledge that presumably people picked up from the magazines and other builders. I guess I do have the advantage of the internet which is both good and bad.

The wing skin is made up of three pieces, and there is a full lenght butt joint between two of them, which I did with the masking tape hinge method. All skins are now done and sanded, I did re-cut the pieces shown in the photo, but to be honest it was probably a negligible improvement over what I could have done with a little light sanding on the original pieces.

I could do with some building advice...

I've dry fitted the wing together, and it slots together very nicely, up until you try and manipulate it so that the trailing edge is at 90º to the root former, as you can see in the photo, it's quite off in it's relaxed state, trying to get it squared up requires some force and also distorts the wing.



I'm I expected to adjust very wing former, slot and hole until it fits without fighting? I can't see any other way to reduce the tension.

Yours in confusion, Gromit

Chris - Both the leading & trailing edges are both TAPERED , only the main spar will be
at 90 degrees to the root rib .
Trust this helps.
Colin

P.S - For Phil - Can you change blue background , difficult to read headers.
Thanks
Colin I

I'm guessing the spar slots are a perfect fit which makes the ribs line up perpendicular to the spar. But the wing requires the spar to be swept back so you will need to lightly sand the spar slots to allow this. You don't need to be too anal about this because the wings strength comes from the spar and the sheeting, not a perfect spar slot

Hi Colin,

Here's a link to the plan PDF: www.topmodel.fr/goodsdoc/100007_time_1331831088.pdf You can see the wing and the reason for my query, I guess it's not a conventional shape.

Thanks Mike, I figured it probably requires little fettling, but just wondered if there was a trick to it that I didn't know.

Chris - Thanks for link - all is clear now.
Colin

MikeSeale wrote: ... You don't need to be too anal about this because the wings strength comes from the spar and the sheeting, not a perfect spar slot

I can't help thinking that Mike is hinting that I might focus on the minutia too much

Anyway I decided the first step was to get the leading and trailing edges to sit at their respective angles without being pulled out of shape by the ribs.

Through careful calculation i determined that the leading edge lugs of the ribs required a 6º taper. To demonstrate a relaxed approach to these things I rounded it up to 6.5º and created a wedge.


With a chisel following the taper of the wedge I removed the offending 6.5º

The result is that the ribs, leading and trailing edges slot together correctly without any tension.


Further work will be required to fettle the other parts of the wing.