Tube plugs for telescope truss

Most specifically, these allow for using threaded rods to shorten-lengthen the truss.  These are fit to glacial bay shower curtain rods, which are one of the cheapest ways to get very nice polished 60" aluminum tubing.  
The clearance holes are for M8 and 3/8 nuts/rods specifically.  

If you want to make this a normal truss member, use one kind only; Epoxy the top nut in, leave the bottom nut free to prevent cross threading. I recommend nyloc nuts for no wiggles. Use threaded rods or long bolts, and match a ball-knob or heim joint.
 

Pair the ball-knobs with these clamps

Now the meat:
If you want to make a hexapod:
Use M8 - LEFT HAND for nyloc nuts, ordinary nuts, heim joints and threaded rods, 6 each.  Epoxy one nut (nyloc or ordinary) into the top, cut the thread (this sucks without a bolt head, but just muscle up on it and put on a show. )  into the plastic and the nyloc nut.  I like 6" of threaded rod just for some wiggle room.  Put the spare nut into the lower cavity, so the rod runs up into it and holds it captive.  

Use 3/8 RIGHT HAND for nyloc nuts, ordinary nuts, 1" OD threaded ball knobs, and 6" threaded rods; 6 each.  Follow much the same procedure here.  

Either way: once the plugs are made complete with end hardware, use slow curing epoxy to join these to the truss poles.

With any luck and a lot of epoxy, you should be able to produce a working hexapod truss

 If this jargon means nothing to you, do one of:

• read up; this is only mildly complicated, but the knowledge on these specific telescope fixtures is scattered across the old and new internet.
• find me on discord 
• find a place where I have put more documentation. (will update this once this place exists)
• re-think making such a complicated telescope. (If the first 3 fail)

I'm hosting the files for my 16-incher for anyone to follow in my footsteps, but these are just provided as-is.  Getting these out there is very high on my to-do list, but I have many other things to do (including fine tune these very systems) before I write a book on experimental fixtures for the amateur telescope.