Hydraulic chuck adjustment

We spent the whole dang afternoon getting the 16" hydraulic chuck of the
Mazak M4 lathe. Had to make special tools and drill out bunged up bolts. We
took the chuck off trying to figure out why we're only getting about half
the stroke ,0.100" vs. 0.190" that the jaws are supposed to have. I'll be a
cleaning the whole unit up tommorrow. Swarf plugging things is at least part
of the problem. "The Kid" is going to find/modify all new special metric
bolts for everything.
Our best guess at this point is the draw-pipe needs to be shorter. By
tightening up the threads at the hydraulic cylinder. Our question, how do
you set the length of this properly?
Or, is there another possible reason for not getting the full stroke?
Reply to
Karl Townsend
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"Karl Townsend" wrote in news:8Zo%d.807$ snipped-for-privacy@newsread3.news.pas.earthlink.net:

The stroke of the rotary actuation cylinder should be longer than the stroke of the chuck. This will probably be a kitagawa unit. Possible problems: bad hydraulic valve, bypass in the clamping cylinder, swarf in the chuck, chuck worn out, something binding in the chuck mechanism. If the drawbar has not been changed, and the chuck used to go the full stroke, then the drawbar length has to be correct. It *can* come unscrewed at the rotary actuation cylinder, as well as the chuck...this would change the length.
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That's what I was going to add. I remember several years back a draw tube coming partially unscrewed. As I recall we put in a set screw to lock it in place.
Reply to
If you have had full stroke in the past forget about drawbar length, unless this (Kitagawa)? came from another machine look at something else.
Put the unit on a cart with the hoses to it and run it, you can see if the cylinder is making full stroke.
The drawbar dead heads at the actuator end so if any thing is modified it has to be done at the chuck end.
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