I recently got an 8mm 3-jaw chuck, Wolf Jahn & Co. I've noticed that it's not operating as smoothly lately. It's stiff to turn. I don't recall this problem when I first got it. Is there anything I should be doing to service it, lube it, etc.? Update...OK, I might have tightened the screws on the jaws too much. I was trying to make sure they weren't walking around, creating issues with chucking something up. Seems to be back to the way it was. Thanks...Kurt
I would get a can of spray gun cleaner and use it to wash out all the old dried up grease/oil then use a good gun lube to oil it. The spray will clean with no residue and both it and the oil is made for hard use and old items then coat it with "Barrier" rust preventive also for guns.
Obviously, also make sure that metal bits from your turning operations aren't working their way inside the chuck, and causing friction and wear when tightening and loosening your work.
Interestingly the same issue came up a few days ago in a German watchrepair forum too. I always tighten the screws just so much that the jaws are sitting tight, but still slide smoothly. When chucking parts with the jaws in 'boring' position (i.e. with the step outside), I tighten them, but not too much, on the part; I then tighten the screws, which clamps down the jaws and, due to a minute rocking movement of the jaws, tightens them further on the part. Obviously, this strategy does nor work, when you reverse the jaws, as the screws will not be accessible. In this case I advance the jaws just as much so that I can pop in and out the part; I then tighten the screws so much that I can still tighten the chuck with some force, but the movement of the jaws would be minimal only; finally I pop the part back in and tighten the chuck. You can also use a piece of steel as tommy-bar with some caution and judicious application of force.
