3/8" tube?

[iter]

I'm trying to decide on launch rod size for my 43" wingspan RCRG, and 3/8" seems about right. The only difficulty is I can't find 3/8" paper tube anywhere.

The way my glider works, the launch lug is mostly internal, so I need about 34" of 3/8" tube. I like the looks of ACME conformal lugs, but they are just too short for what I need.

I appreciate any pointers to vendors who might carry 3/8" tube.

Ari.

[DavidQ]

You should check Balsa Machining Service. I like ordering from them.

They have a 0.375 od x 0.349 id x 34" tube and a .448 od x .432 id x 34" tube. Although not exactly the size you want, you might also find a steel rod that suffices.

Or, you could get consider a carbon fiber rod. My local hobby store has them of various internal diameter's, and they are very, very light.

[rockets4kids]

Just roll your own. Rolling long, narrow diameter tubes is tricky, but it can be done. Roll a bunch of 8" tubes half thickness, let them dry, set them up on your launch rod, and roll more 8" sections centered on the joint.

However, depending on your design, you may not actually need a full length, joined launch lug. Three tubes each several inches long may work just fine. In order to maintain good alignment of separate lugs when gluing, tape your launch rod to the body.

[jimzcatz]

forget rods, use 1010 rail buttons. Most suppliers have them and all club launches will have a rail. You can use brass tubes if you need rods. I have used pvc water pipe in the past.

[rockets4kids]

iter is using an *internal* launch lug -- one that goes through the body of the rocket. I have done this on a number of occasions with large odd-rockets and it works rather well.

[iter]

Ah, BMS! Thank you David.

Ari.

[Rocketjunkie]

You should check Balsa Machining Service. I like ordering from them.

They have a 0.375 od x 0.349 id x 34" tube and a .448 od x .432 id x 34" tube.

Use the .448" id tube on 3/8 rod. You want a pretty loose fit, especially with a long tube like you describe.