"larry g" wrote in
:


"Marty Escarcega" wrote in message
...
Rex the Wrench wrote in
:

With the top nut installed on the spindle, loosening the drawbar
causes the shoulder on the drawbar to come up hard against the nut
which forces the collet or tool holder to unseat from the spindle.
My #645 Index (#9 B&S taper) and my Bridgeport "M" head (#7 B&S
taper) are both set up in a similar fashion.

Rex the Wrench

Rex, is the drawbar something more than a common drawbar?
Must be?

The drawbar has a reduced size hex on the top which leaves a shoulder.
The drawbar is 7/16 dia, the shoulder is about 3/4" dia and ~3/8"
tall, then it reduces to about a 1/2" square for the last inch or so.
The nut that screws on the top of the spindle just clears the 3/4 dia
then has a 1/2" hole in it for the hex to pass through. So in
operation as you tighten the drawbar the shoulder snugs up against the
spindle and pulls in the collet. When loosing the drawbar backs out
of the spindle till it hits the nut capturing the shoulder and the
collet is forced out. Don't quote me on the dimensions but there
close. I could post pictures if needed. lg
no neat sig line

A picture to the RCM drop box would be great, thanks Larry....