Hello,
I bought a carbone fiber wing tube to save some oz in my plane and i would need suggestions to install it. I know pattern's addicted builders install those light tubes in their planes and i would need your feedback to install mine.

Can we do threads in a CF tube? My kit suggest an aluminium tube with screw and fine threads tapped in the tube.
What is the best way to install it?

ref: 24%CA Extra300L, MVVS1.6 gas engine.
Scou

No, it is not possible to do threads in a CF tube. You ought to install a small piece of aluminium tube on the inside of the CF tube and do a thread on that. Maybe someone else knows a better way, though.

Regards,
-Fabrizio

I use a small slice of dowel. I epoxy or CA this inside the CF tube so that the screw will have meat to thread into. You can tap the wood for the machine screw

Another way is to insert a small block of ply with a blind nut attached to it...
These are all easily attached to the tube after the hole in the tub is drilled...This way the hole is aligned correctly.

What I use a small slice of dowel and drill it for a nylon insert. This nylon insert is actually the pushrod part of a nyrod..The yellow inner pushrod. The size that takes a 4-40 threaded insert to make the pushrod....I drill the dowel and insert the nyrod into the dowel and CA it in place. Its about a 1/2in to 3/4in peice of the pushrod material....Then use a small #4 sheet metal screw....I insert the dowel into a pre-drilled tube and capture it with the screw. The tube is not inside the wing...although it was when I drilled the hole in the tube. Use a washer and tighten the screw up to hold the dowel and nyrod assembly in place. Once held tight in place use a small amount of epoxy to hold the dowel....once dry then re-assemble on the wing...and use a slightly longer screw to get good capture into the nyrod material...The yellow nyrod material will act like a thread for the sheet metal screw and the screw will be self threading. Since the screw is tightened into the plastic it will not be vibration prone. If the nyrod ever strips out you simply drill it out and replace the nyrod material....It will work like a charm.

I have done this many times with success I use this same idea to hold on hatches, and belly pans....its simple...easily replaced if something goes wrong(stripped threads) and will not vibrate out.


Troy Newman

Hello Troy,
It seems to have a lot of accessories in your last setup and it's difficult for me to understand exactly what you describe. Let me know if you have a picture or a website showing it!

Fabrizio, you way seems very simple!!
Scou

don't have pictures....

easy setup...once the wing tube is drilled to accept the screws.....

#1 wood dowel that fits inside the wing tube...cut off two lengths of dowel 1/2" long

#2 Drill the wooden dowels on the side of the cylinder not the face to accept a 3/4" long piece of nyrod pushrod material.

#3 Fit this dowel assembly into the wing tube.

#4 use a #4 sheet metal screw and washer to secure the dowel assembly in the tube for glue. This is done through the hole drilled in the wing tube to accept the screw from the wing panel...Note the tube is not inside the wing at this point.

#5 Epoxy or CA the dowel inside the tube.....Once glue is dry remove #4 sheet metal screw and washer.

#6 Its done put the tube inside the wing and install a #4 sheet metal screw into the tube through the wing panel.


Should not need a picture of it...its only a slice of dowel 1/2" long with a hole in it. Then a little piece of yellow plastic pushrod material 3/4" long

Thanks guys,
I will try to put a dowel in that tube and keep it light
Daniel