View Full Version : Centering stock in a 4-jaw chuck
10-13-2001, 06:38 PM
In M.W.Oct.-Nov. 2001 P.55 is a very interesting and new way to me, on how to center stock in a 4-jaw chuck. I have not tried this suggestion but does sound useful. The only thing I have found that helps me is to paint the opposite jaws the same color. I would suspect there are other useful suggestions--Please forward. Spinrow
10-13-2001, 08:48 PM
Don't ever paint your tools! Just get the hang of working with opposit jaws. It soon comes naturaly. You center 1&3, getting the work close and then switch to 2&4. keep alternating. Your dial tells you what pair you need to adjust. Main thing is to be careful not to back off the low side to much. This is where you develope the feel. Set up a chunk of CRS about 6 times and you wil have it. Practice makes perfect.
10-13-2001, 10:21 PM
Spinrow, look on the face of the chuck or on the OD and see if the chuck jaws are numbered, and use these to keep stright which jaws you are working with.
10-13-2001, 11:25 PM
Actually a dab of paint on jaws #1 and #2 sounds like a good idea if they're not numbered. I think of these as the "primary" jaws and when I take the stock out, these are the ones I loosen. If you have to go back in, then just tighten 1 and 2 and you're close to being centered again. They're numbered clockwise btw with #1 opposite #3.
10-14-2001, 02:33 AM
Jim is right to scold you about the paint thing. If you must, get some tool black and do the two jaws but never use paint. But, the point is, if you are having trouble concentrating and cannot pay attention to what you are doing - take a break and relax. If you cannot concentrate do not run the machine! Safety should always be your primary concern - a machine tool can mess you up bad in a blink of the eye.
10-14-2001, 04:03 AM
I carry a Sharpie magic marker with me at all times, I write lots of notes right on machines, easily cleaned off with a bit of WD40 and rag. So just mark your jaws with a marker if you need too.
I always start by matching jaws with lines on chuck, get close and drag out test indicator.
Couple of minutes is all it should take once you have practiced for a year or so. Take your time and don't get flustered, go get a drink of water, pour another cup of coffee if it starts getting to you, you'll get the hang of it fast enough, just don't let it fluster you.
It also helps to make sure the stock you're trying to center is really round, if the last two thou of runout you're chasing just won't go away.
But Halfnut's right, as usual, about practice. After a year or two of doing it, it gets automatic.
10-14-2001, 09:03 AM
As soon as I read the article in the Oct-Nov issue of M.W., I slapped myself upside the head and said "Why didn't I think of that?"
I them promptly made additional wrenches for both my 4-jaw chucks. What a difference!
10-14-2001, 12:27 PM
Aren't you the feller that was moving down here to Missouri while back. Good see you on board, welcome back if that is case, otherwise welcome.
If it is you tell us some stories about your move and setting up shop again.
10-14-2001, 08:06 PM
I would like to thank all the individuals who have responded to my question about 4-jaw chuck setup and their helpful comments. Keep them coming. Spinrow
10-15-2001, 08:22 PM
only use 4 jaw chucks in shop at work.
left a 3 jaw on one night and a"high school machine shop grad"turned a set of rotors from his wifes monte carlo.
the next day he came and asked if i could turn the same set of rotors!
asked him what happen and he said when he stepped on the pedal his head hit the windshield from the brakes pulsating.
take your time and use the 4 jaw chucks.