Trueing chuck jaws, take 2, or a day well spent...

[irving2008]

As discussed in an earlier [ame="http://www.mycncuk.com/forums/showthread.php?t=474"]thread[/ame] I needed to true up the jaws on the lathe. Having finally got some time to spare today and the mill is in reasonable shape and my clamping kit had arrived so I could now properly mount the milling vice I thought I'd have a go.

Sadly my camera battery was flat so put it on charge for later... pic is of the three retainers after I'd finished for the day... only one I took in the end.

First task is to make the chuck jaw retainers, so I cut three 1" x 2" pieces of steel from some 1/4" ground stock I had. A new hacksaw blade made short work of that! I really must get a cutoff saw or mitre saw with and abrasive cutting disc.

Next mount the milling vice on the table... first problem, the 1/2" BSW studs wont go through the 12mm holes in the vice base. Whip the base off, invert, clamp down to the table (oh so easy with a proper clamping kit) and mill out the slots to 13mm.

Reassemble vice, bolt down, align with quill, lock it all down.... end to end on vice jaws (or a parallel held in them) - no movement on the DTI!

OK, face mill in, face off the steel pieces one by one, flip them over do the other side. Easy.

Next, cut the slots... hmmm, hacksaw or mill them? Oh, on a roll with the mill, lets try a bit of slotting. First piece, 3mm slotting cutter in MT3 collet, take light cuts, do it in 5 passes... 2nd piece do it in 3 passes...
3rd piece, get too cocky, 2 endmills later its done. Swap over to the drill chuck and drill the holes to give the required springy effect.

Can't wait to get the new 3phase motor for the mill, all this belt changing is a pain.. the VFD is sitting here waiting for a cheap motor to come along on ebay.

Set up the air grinder spindle in the toolpost, it fits rather well. Fit the jaw retainers to the chuck, lock it down, spin up the chuck and the grinder (and the compressor) and 15min of intense noise later one set of shiney chuck jaws...

chuck up a piece of 20mm ground round bar (offcut from a slide rail)... run out at the chuck now down from 0.5mm to 0.03mm (0.0012"), not bad for an 85y old lathe!