draw tube extension - welding?
I need to extend the length of a draw tube that I have for a 5C set-up that i am putting together. I have see people machine threaded extensions.
My question is, has anybody cut their tube and welded in a section of tube to extend it? It seems to me that tig welding in a piece would be faster and easier than doing the threading. If I keep moving around I should be able to weld it without distortion, especially if i make a bore and sleeve joint, rather than just trying to but weld.
Welding presents no problem, I just furnished a friend with a threaded stub which he had TIGged on. It is a common repair as the threads do strip out wih use.
Another tip. If you are making a new stub, make the threads double length and make the draw tube aout 3/4" longer than needed. Install a spacer on the handwheel end so that when the threads wear out, you can just trim off the bad threads, remove the spacer and you are good to go again.
What material are you using for your draw tube?
(Jim H., nice tip)
Originally Posted by JCHannum
Yep. That's exactly what I did for the the traytop in one of the shops I sometimes work in. Quick and effective repair. Nothing at all wrong with welding.
I tried to extend a draw tube for my 5C collet closer. I had found one that was about 4" short at a tool dealer for cheap. It was made by hardinge. I cut it, turned a champher on each of four ends in the lathe, set it up on a flat surface in vee blocks and welded it back together with a mig welder. It looked like a snake when I got through welding. It would screw up on the collet but it was very tight. I tried to straighten it in the hyd press with limited success.
I finally gave up and found a new piece of 1.5" DOM tubing with a .219" wall. I cut 1.25" internal thread on one end and pressed on a handwheel I had made on the lathe. Viola!! one collet closer.
I bought several draw tubes at a high school auction. All had been repaired by welding a stub end on. If making a sleeve joint, silver soldering will also work. With a little care, warpage should not present a problem.
Thanks guys, I thought it would be OK but figured that I would post it up.
I don't think I can use the double thread length trick because I an using a lever closer set-up.
It's OK thought- for the amount of times I will probably use it the threads will never wear out.
Well, as a thought, you could make a threaded extention, And then replace the extention whenever the threads at the end wear out, insted of continualy cutting it off and welding a new one on (hopefuly very straight!)