aluminum tube

[trucker n]

where can I find aluminum tube that fits inside each other that's a close fit for a log crane and so I can have telescopic boom everything I find is too big

[TRUCKMAKER]

K&S has aluminum and brass tubing. They will telescope. Most hobby shops and tower hobbies carry it. The local hardware store here has it so that's a place to check.

[trucker n]

that's too small

[sparkycuda]

What size tube do you need? http://specialshapes.com is a division of K&S that has many more products and sizes than sold at hobby shops. Might try there to see if they have what you need. Also, I have used http://onlinemetals.com for uncommon sizes and shapes. They specialize in small volume orders.

Ken

[kaptain Jack]

Try luggage stores, some small cases have telescopic retracting handles, most are square (I used one on my wrecker build) but you might be able to score a round one as well.

[arf1201]

You might try a fishing rod holder, I have found different sizes and weights of telescopic rods.

[sassgrunt]

Try also looking at used camera tripods. Legs can be round as well as square-ish in cross section, and each one seems to have it's own locking mechanism for how much the leg telescopes. The thickness of the leg material makes it very sturdy. They're usually easy to find in secondhand stores, and are pretty cheap.