I was associated with a place that bought square and round tube by the
full truckload (44,000 pounds of 3" x.120 tube is a BIG pile) When you
buy like that, the material is welded up to your specs. But the mill
would not guarantee tight fit telescoping.

Go back and read the response about the shims inside the tube, works
well. All the boom trucks and extendable back hoes use this method. This
would allow you to buy the tube you mentioned, tighten it up if
required. A simple weld bead ground down will work for your low loading
outriggers.

DeepDiver wrote:

"RoyJ" wrote in message
ink.net...

The total of .120 is going to make a fairly sloppy telescoping joint. You
mentioned 24" sections, if the overlap is less than about 6" is
will flop a good bit.


Hmmm, that's the same amount of clearance in the purpose-made telescoping
tubing that's sold by Princess Auto in Canada (refer to Grant Erwin's post
earlier in this thread). So is all square telescopic tubing a sloppy fit by
nature? I was hoping for a 3" overlap when the inner section was fully
extended. (By the way, this is for making outrigger-style
supports/stabilizers for a rolling machine stand I'm building. The support
arms are to be withdrawn for a more compact storage footprint.)

I really can't believe this is so difficult. Surely there must be square
telescopic tubing that fits together well, is commonly sold, and does not
cost an arm-and-a-leg. Or am I dreaming about a perfect world again...

- Michael