Atlas/Craftsman 12x36" lathe...questions

I think it requires a knife-edge style puller to remove the front cone bearing properly, although I have not done it on mine
 
Until you get more familiar with it, that is probably the safest thing to do.

ISO 68 is the metric more-or-less equivalent to SAE 20. Mobile Heavy Medium Circulating Oil is what I used for several years. Last time that I needed to replenish, Tractor Supply was carrying SAE 20 ND. But someone recently said that they had discontinued it.

On the open gear grease, look for some that mentions use on open gears. Or if you can't find that, use some that is listed as graphite bearing or carrying with a temperature rating above 100C or 212F. The problem with most of your garden variety grease at the auto parts places is that it'll melt at only slightly above 100F and will quickly sling off.

FYI, the French company TOTAL bought Keystone many years ago. One of the first things that they did after taking over was to discontinue the No. 122.
 
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Former ASE parts guy here. Molybdenum disulfide disk brake wheel bearing grease is great for gears. Good stickiness and doesn't drop off until at least 300*F. Stuff is a bit messy to apply, but generally stays where you put it. Acid brush works good for gear applications. The disk brake wheel bearing greases are rated for much higher heat than traditional wheel bearing grease due to heat soak from brake disks.
 
Thanks. That sounds like something that would be easier to find that what I described earlier. Does it usually come in tubes or cans or squeeze containers?
 
Comes in both tubs and grease gun tubes. You may be able to find some in a squeeze tube, but those are rare.
 
I've made a little progress with the lathe. I was able to get the tailstock completely disassembled, but its still a little stiff...the quill/ram really needs to be turned itself, and cleaned up with some 500-1000 grit sandpaper. I also picked up a thread dial, and mounted it in place.

I did run into an issue, but I think it is simply a lack of understanding on my part (at least I hope). I disassembled and cleaned up the 3 jaw chuck, it was pretty gunky and difficult to adjust. Got everything together, and the jaws meet perfectly in the center, except I cannot get a piece centered in the jaws. I checked runout at the side of the chuck, and its no more than .003-.004", but runout with a piece in the jaws is bad enough you can see the wobble. I can gently tap the piece and get it maybe to 10-12 thousands, but that's about it. Granted, I don't have a piece of rod stock that I know is perfectly straight, but I don't think it would make a lot of difference.

Is there a trick to getting pieces correctly centered in a 3 jaw chuck, or is it likely the chuck itself? I haven't tried the 4 jaw yet, and haven't actually tried it under power...this is with me slowly rolling the headstock via the main pulley.
 
The only "trick" that I know of is that you should have one jaw at BDC (doesn't matter which one except for the practical requirement of having the chuck key on top) when you tighten the jaws. If you have one jaw at TDC, the workpiece will tend to get pinched between the two lower jaws as you tighten them. Make sure that you have all three jaws in their proper slots. Both the jaws and the slots should have 1, 2, or 3 stamped on or beside them.
 
Yes, I have them in their correctly numbered positions. I haven't tried with one of the jaws at 6 o'clock, I'll give it a shot. I can tell you that about the best I can get is *maybe* 15 thou, and that's with a lot of tapping....worst case is, I may end up having to grind a little off 1 or 2 of the jaws.

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Another question, trying to figure out a few things with the back gear assembly that changes to direct drive/low gear. My understanding is you pull the pin on the main gear, then roll the eccentric to engage the two back gears to lower the speed. Is this correct?

The rear gear (#10-242) in the headstock, which the large gear from the back gear assembly engages, has clutch dogs (not sure that is the correct term) that mesh with the rear of the pulley assembly. The pulley assembly can be slid forward enough that it completely disengages the rear back gear....what is the point of this?

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