wing building help

[Phil 9]

the root rib on my plans look like they are at 90 degrees. the wing is a flat bottom trainer type with dihedral and a ply dihedral brace. I built the wing but left out the root ribs with the aim of fitting them in at thr correct angle once I had the wings lined up but this seems difficult. I could glue them in at 90 degrees glue the wings onto the brace but this would leave a gap on the bottom. I could fill and cover the gap but now I am wondering how do most people deal with this situation

[Dwain Dibley.]

It may only be 2 degrees so will be hard to see, is there a measurement for the gap under the wing tip.

Usually you would prop up the wing tip and then add the root rib upright.

You can use the brace to get the wing tip height, using clamps, bit awkward but doable. clamp the brace to the main spar and with the other side flat to the board, hey presto !!

Hope that helps.

D.D.

[Phil 9]

thanks dwain

I thing my problem here is because there is no trailing edge on the wing it is made up by the sheeting, I also sheeted the front (probably a mistake. so now I am trying to fit in the last rib into the sheeting that is oversize and I cant cut it back until the rib is in place

[Hamish]

Epoxy, covers a multitude of sins.

[Phil 9]

Posted by Hamish on 11/05/2017 21:14:08:

Epoxy, covers a multitude of sins.

this may be the easiest solution in this case

[TigerOC]

According to a Telemaster 70" plan I have the dihedral is 50mm at the wing tip. So raising the tip to this height and inserting the rid and insuring it is at right angles to the table surface should resolve this issue. if you can tack or pin  the root ribs of both wings at this angle then check that the dihedral braces matches and then glue permanently.

Rob

Edited By TigerOC on 11/05/2017 21:27:19

[Nigel R]

I'm inclined to agree with Hamish, seeing as the sheeting is already in place.

Future options;

Use a not-quite-90 degree template, to set the root rib angle when framing up ribs & spars.

Prop the wing up to the right height when you've done every other rib and the spars but before the sheeting, fit root rib at 90deg to board.

My favourite:

Use a thicker root rib, 1/8 or 3/16 or 1/4 and sand in the required angle when joining.

You can build in a good strong place to mount a central wing dowel using the thick root rib, too. If your design uses a dowel that is.

[Ace]

How about seting one wing flat with the rib at 90', then prop the other wingtip up to the desired height, then running a 90' block covered in sandpaper back and forth along the proped wing to take the top edge off front and rear sheeting? Then set the rib and brace. Ace

Edited By Ace on 12/05/2017 08:32:08

[Phil 9]

Posted by Nigel R on 12/05/2017 07:40:15:

.

My favourite:

Use a thicker root rib, 1/8 or 3/16 or 1/4 and sand in the required angle when joining.

You can build in a good strong place to mount a central wing dowel using the thick root rib, too. If your design uses a dowel that is.

This sounds like it will work well for me in this case thankyou Nigel. There are also a few good tips here that I can use in future builds

[Nigel R]

if you're doing a single dowel supported by the root rib, I would -

1/8 liteply doubler, spar to LE, outside of the 1/8 root rib

make an undersize channel in the 1/8 rib, from LE back to spar - before sticking the rib in place (either at the right angle, or at 90deg and then sand to the correct angle). e.g. if using 5/16 dowel make a 1/4 or 3/16 channel.

extend channel through LE

join wings

drill out the channel to 5/16 (so the drill bites just a little into the liteply)

at this point you might also wish to fit a small spanwise plate (width of fuselage) at the LE, sand back the LE a little first to give a nice flat area for it

bury the dowel in its new home with epoxy, don't spare the horses