I have had a couple requests for CF wing-tube spar clamps like the ones used in the X-UAV and Zeta foam planes. Some time ago I had a "rough" landing with one of my older FX-61 wings so I took the spar clamp out and made a few prototypes. Mine are a little different because I wanted them to be easily printable and durable in just about any print filament. The pieces shown on this page are done in PLA and appear they will work very well but I would recommend ABS or POLYMAX for the toughness and UV tolerance.

There is an A & B version for the left and right wings. The 10mm x 8mm clamp is used with a 10mm main spar and an 8mm inner spar. Generally the inner spar is the full length of the wing (half) with the clamp installed about 1/3 of the distance in from the wing root. I (will) put a drawing up to show this "general" positioning. Take note that the 8mm inner spar must fit inside the 10mm main spar for this to all work.

You'll need an M3 Nyloc Nut and M3 x 10mm screw. Use a socket head for best results.

I'll be adding a couple more sizes soon.

Maker Select IIIP

No

No

0.2mm

50%

Print speed = 30
Printed vertically. See "print Orientation image.

There is a need to cut a small slot so that the clamp will work as designed. You can see the slot in the pictures and it is well marked in the print. Use a fine hacksaw blade to make the cut by hand.

I did it this way to avoid using a (sometimes) messy structure.