- Joined
- Jan 23, 2015
- Messages
- 60
I've had this JDP 20MF floor model Jet drill press for 13 years. I bought it new. I've drilled up to 3/4" mild steel and cast and never have been able to stall it out. Average work is more like 3/8 to 1/2 holes mostly in mild steel and its only used a few times a week and on projects so no production stuff.
I've noticed increasing run-out at the drill tip to the point its visible. Careful bit placement in that big 3/4 chuck is required to reduce it but I can't eliminate it. Two weeks ago I put my indicator on a piece of chucked up drill rod and measured .005 run out. Up above the chuck on the arbor shaft I was getting .003 to .004 run-out.
Put in new spindle bearings and was able to reduce run-out to about .002" as measured just above the top of the chuck and again at the drill rod. I thought it should have been zero or not more than half a thousandths but maybe I expect too much?
Also, with drill turned off and indicator on the arbor shaft just above the chuck I can put finger pressure on the chuck and cause .004 to .005 deflection pushing front to rear. Much less deflection pushing side to side. I do not think there is any movement of the arbor as it fits both the chuck and spindle very tightly.
The question is what's going on there? Is that kind of movement to be expected? With the spindle locked in to the quill with new bearings I wouldn't think you'd get measurable deflection from moderate finger pressure on the chuck. Spindle is fully retracted when this happens.
Thanks for any help in solving this.
Jerry
I've noticed increasing run-out at the drill tip to the point its visible. Careful bit placement in that big 3/4 chuck is required to reduce it but I can't eliminate it. Two weeks ago I put my indicator on a piece of chucked up drill rod and measured .005 run out. Up above the chuck on the arbor shaft I was getting .003 to .004 run-out.
Put in new spindle bearings and was able to reduce run-out to about .002" as measured just above the top of the chuck and again at the drill rod. I thought it should have been zero or not more than half a thousandths but maybe I expect too much?
Also, with drill turned off and indicator on the arbor shaft just above the chuck I can put finger pressure on the chuck and cause .004 to .005 deflection pushing front to rear. Much less deflection pushing side to side. I do not think there is any movement of the arbor as it fits both the chuck and spindle very tightly.
The question is what's going on there? Is that kind of movement to be expected? With the spindle locked in to the quill with new bearings I wouldn't think you'd get measurable deflection from moderate finger pressure on the chuck. Spindle is fully retracted when this happens.
Thanks for any help in solving this.
Jerry