Cromwell S800 Mk3 lathe

The spindle runs in tapered split plain bearings.spit plain bearing.gif
 
As the bearings wear they can be tightened with these threaded adjusters.bearing adjusters.gif
 
End loads are carried with these plain thrust bearings. They are also pined to the bearing adjusters.plain thrust bearing.gif
 
On the back is a threaded lockable collar to adjust the end play.threaded end play adjuster.gif
 
OK this is the adjustment procedure I am proposing.
One bearing at a time.
Back off the inner adjuster to allow the bearing to be tightened.
Screw in the outer adjuster till the spindle just nips up then back off a bit (not sure how much).
Screw in the inner adjuster to lock the bearing in place.
Repeat with the other bearing.
Finally screw in the end play adjuster till the spindle nips up then back off and lock.

I will give this a go later in the week.
 
RodF said:
OK this is the adjustment procedure I am proposing.
One bearing at a time.
Back off the inner adjuster to allow the bearing to be tightened.
Screw in the outer adjuster till the spindle just nips up then back off a bit (not sure how much).
Screw in the inner adjuster to lock the bearing in place.
Repeat with the other bearing.
Finally screw in the end play adjuster till the spindle nips up then back off and lock.

I will give this a go later in the week.
Click to expand...


Hi Rod, I had similar problems with mine, the mainshaft just got tight all of a sudden. I had more or less adjusted it the way you describe. You have to make sure the inner and outer locking rings are acting on the taper, and work together on it. It can be difficult to feel when the locking rings are in contact, they are quite tight to turn anyway. I found I had to more or less use the inner rings to first push the taper out a bit, and then clamp from the other side. I was surprised how much I had to back everything off, but now it runs very smoothly and without play.

What did you use for your wick oilers? I used 2mm paraffin lamp wicks, but they seem to syphon the oil out of the reservoirs overnight. I am using a light weight hydraulic oil like Hyspin 32.

I am still in the process of finishing the Cromwell off, but on initial commissioning it appears to be very accurate, and nice to work with. I don't like the visible cross slide screw, which seems vulnerable to swarf ingress from the top, maybe I'll have to come up with some kind of cover.

Good luck, I am sure it'll come good, just needs tinkering!

Regards,

Paul
 
Hi Paul, mine has no cover at all. It is an early model with the short tail stock. It is number 845 so I assume it is the 45th production model so must have been built in 1946 or 1947.
IMG_3284.JPG
 
Cutting metal, no jamming yet. This is the guide for the broaching tool to cut the key ways in the gears I made. A few more hurdles yet. Like a back plate for the 4 jaw chuck. A mount for the RPM display.
IMG_3295.JPG IMG_3297.JPG
 
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