Warm bearing

[Ray C]

I'm not sure what Atlas you have but mine had one taper bearing at each end. -The same style bearing as what you'd find on an automotive front wheel spindle. The tapers were pointing away from each other which might explain why one got warm and the other didn't. One was getting forced into the race and the other was getting forced out.

For sure, I'd say the warmth came from driving w/o a dog. I use to run mine for hours on end and I don't recall it ever getting warmer than "forehead" temperature.


Ray

Interesting thought...yes I was working a rod between centers and I did have the tailstock cranked out pretty firmly as I was working right up to both ends and trying (successfully) to use the dead center friction to drive the (aluminum) rod for very light cuts. A 15 degree or so rise sounds about right. It was hot in the garage...South Texas in July...but it wasn't 120 degrees for sure.

IIRC on the Atlas 10F the right HS bearing is a cone/thrust bearing and the left bearing is parallel/axial load only? That might also explain the right bearing only warming up.

 

[iron man]

I dont know but if it was a wheel bearing it would be packed with grease since you cannot the 20 weight oil seems awful light for an open bearing. It is like putting oil on open gears instead of open gear lube the bearing will just sling it out of there that is why I went to the straight STP on the timpken bearings on mine it is more like what you would find in a car rear end the principal is the same. Mine never heated up after I did that you might want to give it a try once what is it going to hurt?? The stuff sticks like honey.. Ray

 

[wa5cab]

First, all Atlas or Atlas/Craftsman 6", 10" and 12" metal working lathes that do not have sleeve bearings (6") or babbit bearings (10" and 12") have two dissimilar Timken tapered roller bearings on the headstock spindle.

Second, if you fill the oil cup with SAE 20 and it soon runs out past the dust covers (a) you must not have the felts in the oil cups and (b) you are using 'way too much oil. The purpose of the felts is to meter the oil delivery. The rollers are supposed to be running on a film of oil, not submerged in oil. The felts are supposed to be topped up every morning or before every use if that is less frequent. You can buy felts from Clausing. The postage will cost about as much as the felts. Before I discovered that Clausing was still in business and still carried a lot of Atlas parts, I tried to make some. I wasn't happy with the results and spent more than what Clausing charges for several sets. If the felts in your headstock are originals, you need to replace them. Especially if your machine is from the 30's or 40's.

Bearing preload instructions are given in the Atlas Headstock Technical Bulletins (copies in Downloads). The bulletins also telll you how to field strip the headstock and reasemble it. The early MoLO's gave a different procedure involving running the lathe for (I forget the specific amount of time) some time to warm up the bearings and spindle before final adjustment. Someone sat down and calculated how much the spindle length increased (Bulletin says 0.002") during warmup and came up with a way to achieve the same results at room temperature. Which in a nutshell is to tighten the spindle collar good finger tight and then tighten it two teeth of the 32T spindle gear.

My right spindle bearing runs hotter that the left, too. I always put it down to the fact that it carrys most of the chuck weight.

Until about 1960??, the recommended oil viscosity for all Atlas lathes was SAE 10. Then they changed all the lube charts to read SAE 20.

Robert D.