lathe 4 jaw chuck

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Just got lathe home pics yet to come.my question is that when i tighten the jaws on a shaft it only hits on the the end of the jaw away from the head and that makes the shaft not clamp secure its an old cfatsman brand chuck can i get new jaws to fix it or just get new chuck.I will try to get pic cause I know this is hard to understand
Reply:Pics..By all means......zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:I'm no expert, but sounds like either the jaws are the wrong ones (to small for the "T" track they slide in) or the "T" track in the chuck is worn...You could remove the four jaws and do some close measuring with a Cal.
Reply:I'm thinking he has soft jaws that have used past their serviceable life..Need PICS!!!!...zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:On most 4 jaw chucks the jaws are independant of the others, A 4 jaw chuck of this type is relatively inexpensive, and not much affected by wear as the operator has to center the work manually by adjusting each jaw.Some 4 jaws move all 4 jaws together, these are more expensive and also more subject to wear, similar to a 3 jaw."The reason we are here is that we are not all there"SA 200Idealarc TM 300 300MM 200MM 25130a SpoolgunPrecision Tig 375Invertec V350 ProSC-32 CS 12 Wire FeederOxweld/Purox O/AArcAirHypertherm Powermax 85LN25
Reply:Seems odd that the outer ends of the jaws, rather than the inner ends, are bearing more heavily on the work (if I understand your description correctly).As indicated by others, the first thing to do is determine that the jaws and chuck body slots are not excessively worn or damaged.  Look closely for cracks in the jaws or the chuck body caused by over-energetic tightening of the chuck.  Once you decide that the chuck is basically sound, it is possible to grind the jaws in place using a tool post grinder but unless you are looking for a challenge or you have an odd spindle thread that is hard to find in a replacement chuck (as I do), it is undoubtedly more practical to buy a new or used chuck in good condition.Tool post grinders are typically quite expensive but you could probably do a small job like this by adapting an inexpensive die grinder having a long, cylindrical shaft housing that can be mounted in a block clamped to your cross-slide.  I did this decades ago using a Bosch die grinder by boring out an aluminum block to accept the die grinder cylindrical shaft housing, slitting one side horizontally to allow (gentle) clamping of the shaft housing, and boring a vertical hole for the hold-down bolt.  This was, however, for small workpieces, not for jaw grinding, so I could use small diameter mounted grinding stones that were rated for the 30,000 RPM speed of the Bosch die grinder.Most die grinders are not that fast, but you must be sure to use mounted stones that are rated for the speed of the grinder or reduce the grinder speed to below the rated speed of the stones..  This could be a serious limitation for mounted stones or wheels larger in diameter than the front housing of the die grinder as would be required to grind the full length of the jaws.  I notice that Harbor Freight is offering a 25,000 rpm long shaft electric die grinder that might work for $30.  Probably won't last long, but OK for a project like this.Jaw grinding is a more common practice with 3-jaw scroll chucks to improve workpiece centering but with a little fussing to set up, I imagine it could be done with a 4-jaw chuck to restore parallelism of the clamping surfaces.   You would have to come up with a scheme to preload the jaws outward against the acme screw threads so they are in the clamped configuration.  This could be tricky.  Spiders are sold to preload 3-jaw chuck jaws for grinding but I've never seen them for 4-jaw chucks.Once you have a good setup with all jaws equidistant from the spindle axis and preloaded to take up slop in the jaw tracks, you turn on the grinder, turn on the lathe,  and pass the carriage back and forth the full length of the jaws while feeding the slide outward very gradually so you take extremely small amounts off the jaws on each pass.  Once you see that the full length of all of the jaws has been dressed you continue running the carriage back and forth with no outfeed until the grinding "sparks out," i.e.,  all grinding has ceased.  This assures that there is no deflection of the work or the die grinder or the lathe to disturb the quality of the outcome.Good luck.awrightYou have to disassemble the chuck and clean out the grit after grinding this way but that's simple for 4-jaw chucks.Last edited by awright; 08-30-2010 at 04:32 AM.
Reply:Thanks for all the input after I took it apart and looked it over good it has alot of damagedand broked threads so i am just going to buy another one not sure if i should get new or used and is there a brand to look for and any to stay away from I want an independent jaw .
Reply:www.CDCO.com has import 4 jaws that are rather inexpensive.  I haven't purchased one yet, but plan on getting an 8" from them.  My lathe isn't near stiff enough to warrant a $500 chuck, so the cheapy will do me just fine for now.If I ever upgrade to a more robust lathe, then the more expensive Bison might be worthwhile.MarkI haven't always been a nurse........Craftsman 12"x36" LatheEnco G-30B MillHobart Handler 175Lincoln WeldandPower 225 AC/DC G-7 CV/CCAdd a Foot Pedal to a Harbor Freight Chicago Electric 165A DC TIG PapaLion's Gate Build
Reply:I have 8 chucks for just 1 lathe. Ebay is my friend for them. I have a few China ones that were cheap but seem to be pretty good. And a few oddball English and USA made ones. I even have a junk 8" one just for turning junky steel then i use the good ones...BobBob WrightSalem, Ohio  Birthplace of the Silver & Deming Drillhttp://groups.yahoo.com/group/southbend10k/http://groups.yahoo.com/group/sawking/1999 Miller MM185 w/ Miller 185 Spoolmate spoolgun