I went to use the 3A/3C collet on our 9" South Bend the other day, and was
mystified as to why I was able to keep turning the drawbar handwheel
without the collet tightening. It was pretty easy to figure out: the
threads are stripped out.
So now I'm left wondering how to approach fixing this little problem.
Here are the options I've thought of:
1) Buy another drawbar
2) Buy a commercial tap of the appropriate thread (which I'm assuming is
available at MSC - I haven't looked yet.) Use this tap on a piece of new
stock. Trim the diameter down to a shoulder to allow some relatively thin
tubing to join the new threads to the old bar. Harden? How much? Cut
off the old bar and make a recess for the tubing to fit on and hold them
together. Silver solder or braze.
3) Shorten the existing drawbar (it's about 5/8" too long anyway). Bore
the new end out to so that the commercal tap will fit down far enough.
Tap. Does it need to be annealled first? Hardened afterward? How much
4) Keep using the 5C collet chuck and forget about the 3A's and 3C's.
TIA for your comments,
18 years ago