Atlas Craftsman Chuck Jaws

JDR

JDR

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Hello,
I am cleaning up an old Atlas Craftsman 12"x36" lathe. I just started cleaning and checking out the 3 jaw chuck. It has "2165" stamped on the face. The inside jaws are in pretty bad shape. Trying to decide if I should try to fix or replace them. They don't have them on the Sears website but there is a note that this chuck was made by the Warren Vise company. Any ideas where I can find replacements? Thanks!
JDR
 
I would just buy a new chuck, adjustable. You can a decent one for under 300$ from little machine shop. Other wise eBay seams to have a bunch of stuff for these. Depends if your looking to restore to original or use for good fabrication
 
JDR,

If your chuck jaws are in bad shape, likely the scroll is, too. If you still have the outside jaws, put them in the chuck and put a piece of ground round stock in them and check the runout. Repeat at several different diameters. If you can't find ground round, mark a 0 reference in line on each end and chuck a piece of round stock in the outside jaws with the reference mark in line with the #1 jaw.. Using a light cut (because you won't be gripping much of the material), cut on it until you re into the part about 15 thou at the shallowest point. Loosen the chuck and flip the part end for end taking care not to rotate it and repeat, being sure that the second cut slightly overlaps the first and that the finish diameter is the same as from the first cuts. Note by how much the two diameters are not concentric. Rotate the part 90 degrees and repeat. The worse of the two cases is indicative of the chucks runout with good jaws (the outside jaws usually see very little usage).
 
Thank you for the help guys. Overall, the chuck is in pretty good condition. It looks like the previous owner had ground on the jaws for some reason.

I would like to keep this original, but will likely have to replace the chuck. Does anyone have experience with Shars products? I am looking at their AXA QCTP as well.

6" Shars chuck.
 
That looks like a reasonable one for an Atlas built 10" or 12" (any model, not just the few numbers shown). And the sale price looks good ($150). The only down side that I will mention is that chucks (not just Shars) with separate back plate and reversible jaws are going to hang out from the spindle nose maybe an inch more than the original chucks with integral back plate and two jaw sets. Other than that, it appears to be a good deal. Don't fail to read the fine print. You will have to finish machine the face of the chuck that bolts up to the chuck body.

One other point - after you machine the back plate and attach it to the chuck. Temporarily match mark the plate and chuck. Check the runout on a short piece of precision ground round stock about 3/4" to 1" in diameter (an unused piston wrist pin from a better class engine makes a good piece to keep around for this sort of thing, or you can buy a well made 3/4" diameter spindle/tailstock alignment test bar and use it for this as well). Record the results, and repeat with the back plate attached to the chuck in the other possible orientations. Use the position with the least runout, and permanently match mark the plate and body for this position.
 
One other comment on tool holders for the AXA - over the years I have found that the #16 or #116 turning and facing holder that holds two triangular replaceable cutters gets used more often than any of the others for general turning. But unless they have redesigned it to correct their error, don't buy the one from Shars as it cannot turn up to a step or shoulder because of the cutter orientation. Aloris makes one but it is quite expensive. Yuasa made one but they no longer make QCTP's. They may have sold that line to Shars, but if they did, for some unknown reason Shars changed the 116.
 
Thank you for the advice on the chuck jaws and tool post. This has probably been asked here before, but is anyone familiar with CDCO Machinery? Their pricing is about the same as Shars.

I think I am going to try to re-face the chuck jaws. If that doesn't work I will find a replacement. Just hate to see that old tooling not get used!
 
You're welcome.

I've no personal experience with CDCO.

Before you set up and re-grind the inside jaws, you should disassemble the chuck for cleaning and inspection. The scroll is the disk with threads in its face that moves the jaws in and out. Check the threads, looking for signs of damage, like gouges and flat spots. Thread wear, so long as it is general enough to uniformly affect all three jaws at any given diameter, isn't really a critical problem. But wear on the spigot that the scroll runs on and on the center hole that runs on the spigot could be. I've no hard figures on what the original running clearance was. But you can at least measure what it is now, with the chuck cleaned and only lightly oiled (not how it would be when you put it back together). With the scroll in place on the spigot and the part of the body not containing the spigot not attached, mount a dial indicator so that it can indicate radial movement of the scroll relative to the spigot. Ideally, there should be none. But practically there has to be some clearance or you couldn't rotate the scroll.
 
I've purchased many things from CDCO. Also, CME tools carries many of the same things and I've had several fine transactions with them too.

Ray
 
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