Originally Posted by
emexcee380
Sounds like you're on the right track.
Not tremendously knowledgeable about Bridgeport/Hardinge VMC's
but most VMC drawbar designs are similar.
At the top of the drawbar is (usually) a preload nut followed by a
certain number of belleville washers stacked in a specific arrangement.
A common number is 128 bellevilles, stacked 4 concave then 4 convex.
At the bottom is a collet of some sort. Sounds like yours is the segmented
or "finger" type. A simpler type uses 6 steel balls to grasp the retention
knob.
If you see what looks like an allen socket looking up thru your spindle taper,
this is the fixing screw. If it won't loosen with the top of the drawbar being
held by a helper, it might be loctited. If so, you'll have to heat it to approx.
500-degrees F. to break the loctite bond. (Let's hope not ! )
Once you loosen and remove the center fixing bolt remove the segmented
collet (often simply held together with a circular spring or oring). Then remove
the drawbar out the spindle taper.
Use a telescoping magnet to begin pulling out the bellevilles from the top
paying attention to the orientation. Even if you find no broken ones, bellevilles
(like) any spring tend to "sack" after x-number of cycles, thus decreasing
the available retention spring force of the drawbar. Go ahead and replace them.
Don't buy OEM - the delivery will suck and the price will suck even more. Just
Google "belleville washers" and buy what you need from a belleville mfg. (just
like the machine tool builder did.)
Hope this helps.
emexcee380