gosk8ing

Hey,

Im scratch builder a Katana 46 size, and am going to use a carbon fibre tube to join the wings together, so i can take them off for transport. The tube has to be 700m long and a diameter of about 12 - 15mm. How thick should the wall thickness be so that it wont snap in flight?
Wingspan is 1330mm.

Cheers

russian

My Feedback: (23)

1mm. will be OK!

Magne

Hello.
PBG Composites in New Zealand make carbon wing tubes.
http://www.pbgcomposites.com/product...arbonTubes.htm
I would suggest the PBG 101TS tube and socket set, suitable for small wings and large stabs.
Diameter is 3/4", wall thickness 0,035"
Personally I think your estimate of 12-15mm dia. is a bit on the low side, but it is your choice. 1/2" tubes (12,7mm) are typically used on the tailplane of 2m pattern models. Your wing is considerably larger than that. (Have you done any strength calculations?)

Magne

gosk8ing

Hey,

Thanks for the info. I havent done any strength calculations. The reasons why i stated 12 - 15 mm is to make it easier to build into the wing (many reasons, cant explain).


Cheers

gosk8ing

Hey again,

Also, Im not using this as the main spar in the plane. Its only the wing joiner (dont no if that changes anything cause the wing joiner takes all the load).

CHeers

gosk8ing

Hey,

With the tube and socket set, whats the socket? Is it just for the fuse or do they come with sockets for the wings?

Cheers

Magne

The wing joiner takes all the bending load, no matter how strong your spar is. If it is too weak, then it will break in the middle.

The soket is the same length as the wing joiner, and is basically a sleeve that fits outside the joiner. Typically you would cut the sleeve into three parts, one to go through your fuselage and one in each wing half. The socket is much thinner/weaker than the wing tube itself, and is not made from carbon, as it does not take any bending loads.

Is this a foam wing or a built up wing? With a foam wing, you would want to mount a light plywood rib at the end of the socket (or actually, 10-20mm inside the end, and plug the end of the socket) This plywood rib would distribute the forces onto your wing skins. For this size of model, you would not need a spar in a foam wing.

Magne

gosk8ing

Hey,

Thanks for the info. The other day i bought the PBG103TS 7/8" x 30" - Tube & Socket
0.035" 83g. They didn't have the 5/8" or 3/4" in stock.
I didnt realize how expensive they are. The price was $80AUD and i got it down to $55AUD.Makes me think that just shouldv'e bought a kit. I knew scratch is a bit more than kit, but not that much more.

CHeers