Spindle lift test, how far?

Mpehon · Jul 21, 2021

Hello all,
I have recently completely restored a wartime SB13. Upon pulling the spindle caps, I found they were shimmed with pieces of cardboard and old notebook paper and the spindle had .015 deflection. I ordered .0015” brass shim stock and plan to install new shims. In the “restoring SB lathe” book it suggests shimming the spindle to .0007-0010”, but I have noticed some threads and forums suggesting anything up to .002” is fine.

Is there a preferred lift test measurement?

Thank you!

texasgeartrain · Jul 21, 2021

Deflection is bending, i think you mean checking oil clearance.

The age of your machine, i guess cast iron on headstock is your bearing. Id try to get the oil clearance between.001 and .002, with back and forth thust between .0005 and .001.

Use a prybar to lift spindle. Put about 50 to 70 pounds of your weight into it.

Mpehon · Jul 21, 2021

texasgunsmith said:
Deflection is bending, i think you mean checking oil clearance.

The age of your machine, i guess cast iron on headstock is your bearing. Id try to get the oil clearance between.001 and .002, with back and forth thust between .0005 and .001.

Use a prybar to lift spindle. Put about 50 to 70 pounds of your weight into it.

It is a cast iron pillow block with a split bronze bearing and bronze expanded plugs, which the capillary wicks push through the bottom to oil the spindle bearing surface.

Thank you for the reply. Will move forward with installing the new shims and checking oil clearance.

michiganbuck · Jul 21, 2021

I'm not SB expert but with going from crap shims to decent shims I think I would blue it up and feeling the shim stack to get best just contact looking for good close handles side and far side, and chuck end and back end fairly close. Then shoot for about .002 to .001 clearance. Then make shims stack of the largest thickness and the fewest thins.
I think a wood 2x2 is a good lever because you can't hurt anything with that.

Start with very clean of bugs and bruises and just two fingers tight feeler gauge each shim place and draw a map of that. Ballpark may be adding .001 to .003 at each place.

animal12 · Jul 21, 2021

make sure that the bearings & spindle are wet / coated iwith spindle oil before you do the lift test
animal

Ohio Mike · Jul 21, 2021

The South Bend directions for this process is included in Form 2002. Link below includes this and other service guides you will find useful. Keep in mind its a old used machine, you will likely never be able to hit the new specs.

http://vintagemachinery.org/pubs/1617/25079.pdf

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Spindle lift test, how far?

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