Clausing 100 Spindle bearing adjustment

[mx6er2587]

I recently acquired a Clausing 100 mk3 in quite nice condition and have begun tuning it up. One of the first things to tackle is getting the preload right on the spindle bearings. Some searching has turned up that "the chuck should go about 1 revolution when turned quickly by hand." My question is in what position should the lathe be in when performing this test? Back gear off is obvious, but should the belt be under tension? Should the clutch be in or out?

 

[markba633csi]

Spindle should be free to spin, so everything loose, leadscrew gearing dis-engaged
-Mark

 

[wa5cab]

Or, since both machines have about the same spindle bearings and both have a 32T spindle output gear, you can use the Atlas standard instructions.

Shop temperature should be at around 70 degrees F.

Mount one of your chucks on the spindle.

Place FWD/Off/Rev Tumbler in OFF position.

Lubricate spindle bearings and run motor for a few minutes.

Loosen set screws in threaded collar on left end of spindle.

Loosen the collar about half a turn.

With a wood block and the palm of your hand or a small shop hammer, bump the spindle toward the tailstock until you can confirm that the spindle has definite end float when you push and pull on it.

Set up a dial indicator on the carriage, compound or tool post to bear on the chuck face and confirm that spindle has non-zero end float

Tighten the threaded collar until Dial Indicator indicates zero end float. Run motor briefly, stop it and re-confirm zero end float. Continue tightening collar 1/16 of a turn or 2 teeth on the 32T spindle gear.

Tighten set screws in threaded collar.