Atlas 10F-28 purchase questions?

Thanks for all the info. I'll buy some shim stock this week and hopefully work on getting the bearings shimmed correctly. I believe you are right on the size of the bolts in the bearing caps, they looked like they are that size. The lathe is pretty complete the only problem that I have run into is the power crossfeed does not work. The crossfeed gear is proabably broken, I'll get to that one day. Will probably tear the lathe all the way down and clean it up and repaint this fall. What color were the Atlas lathes originally? Mine looks like it was dark grey.

Bob
 
Robert ,
Would the play likely be reduced if there was fresh correct grade oil in the oil pots & if it had managed to circulate round the bearings once they had become warmed up say after 1/2 hr of running ?
 
That's possible. I'm going to pull the spindle and get it all cleaned up and get all the years of accumulation of grease and grit cleaned up. It's been sitting for at least the last four years that the previous owner had it and I don't know how many years prior to that. At least is had a layer of oily grime on it and so it didn't rust up. I'm going to pick up some shim material this week and start with the original thickness of shims and go from there.

Bob
 
David, the half hour warm up period has to do with lengthening of the spindle due to temperature rise. Which the Timken bearing headstock Technical Bulletin implies is around 0.002" total. So it would apply to the ball thrust bearing, although the babbit bearing instructions that I copied out of a MOLO and put into DOWNLOADS don't mention it. And I don't know that 0.002" is the correct figure for the babbit case. But the spindle is much longer than the journal diameters. So for the same temperature rise, the increase in journal diameter would be much less than 0.002".

I've no experience with babbit bearings except in internal combustion engines. And there I have always had a manual that gave the hard numbers for the clearance. And had a way to check it, but I can't recall the name of the material that you do that with right now.

Clausing might just possibly still have the shims available. I never asked them.
 
Wa5cab,

Are you thinking of Plasti gauge?

My grandson has been staying with us for the last week and went home yesterday, so I had time in the evening to work on this. I bought shim material and cut a bunch of shim for the right hand bearing, so I had 0.010" of shims for the front and back. I was able to get it shimmed to .008 both front and back and torqued to 20 pounds before it started to drag. I then checked how much movement was in the spindle (removed chuck) with the indicator on the register of the spindle. I used a 3/4" round bar and was able to get 0.0015" of movement vertically. I need to check the left hand bearing tonight and see if that needs shimming. I'm going to get some Plasti gauge and check bearing clearance just out of curiousity.

I filled the oil cups and run the lathe for about 15 minutes. The oil in the right hand cup only lasted about 3 minutes before I needed to put more in. Does that have to do with loose bearings or how does the oil stay in? Just due to tight clearances?

Bob
 
Yes, Plasti-Gauge was what I couldn't recall the first word of. Thanks.

When checking the drag, the other bearing cap must be loosened. If it wasn't, loosen the bolts and see what you get for drag with only the right bolts torqued. Then only the left ones. And then both. Note the instruction to loosen the bolts 1/8 to 1/4 turn at spindle speeds over about 800 RPM.

On the oil usage rate, yes. The rate should be inversely proportional to the clearance. I would suggest putting a low density felt plug in the cup, as the factory dig after around 1950. Top it up before every use or every morning.
 
Yes, I loosened the left hand bearing cap. I noticed loosening the bolts when turning over 800 rpm's. I'm going to check the clearance with Plasti gauge just to see what it is.

I was wondering if the oil cups needed felt in them, I have some around and will have to find it. And get some correct weight oil for the lathe.

Bob
 
The factory recommendation on oil was SAE 10 ND until 1957 when they switched to SAE 20 ND. For a time, SAE 20 was hard to find in a lot of places in the US. So I was using a Mobile ISO 68 Heavy Medium Circulating Oil. But recently several places including Tractor's Supply began carrying it in gallons. Although the factory never mentioned it, I have always used way oil instead of straight SAE 20 on the ways only. For the change gears, the grease that Atlas recommended is no longer made. A French company (Total, pronounced "toe-tal") bpught the maker and almost immediately discontinued it. Use a graphite bearing grease with a high temperature rating (not because it is actually a hi-temp application but because the hi-temp greases won't liquefy under normal operating conditions.
 
I decided to redo the right hand bearing and check with plastic gauge, plastic gauge said .002 clearance, but couldn't even rotate the spindle. I started back over with .010 shims and worked down from there, while torquing to 20 ft pounds. Ended up at .006 on the shims, both ends and torqued to 20 ft pounds and was getting .0015 movement in the spindle. Torqued to 25 ft pounds and was down to .0005 movement in the spindle. I'm going to back off to 20 ft pounds tonight and recheck the drag, will probably leave it there unless accuracy in turning is not enough.

The oil cups drain almost immediately when filled. I'll run them like this for a while to see if that slows when I put some felt in. I cleaned up the chuck and cross slide last night soaked the in Purple Power for an hour and the dirt and crud just came right off. Noticed under all the crud that the compound had been brazed at one time, it was machined smooth on the bottom and looks like a good job. If it doesn't hold up I'll find another. I might as well paint it whiles it's torn down. Any recommendations on paint color?

Bob
 
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I assume that you must mean 0.0015" @ 20 lb-ft bolt torque, since you reported 0.0005" at 25.
 
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