Clausing 5914 - spindle bearing preload adjustment

From "Re: Continuing lathe chatter (from people now, not the lathe)"
posted 4 June 2008 by Joe Gwinn:
> >> >> Mine may not be truly equivalent, since mine has three belts
> > >> >> applying stress to the side of the shaft. But I get what feels like
> > >> >> a
> > >> >> 3:1 or perhaps 4:1 ratio of starting force vs moving force. It
> > >> >> pegged
> > >> >> the force gage which I was able to find -- at about 1.5 KG applied at
> > >> >> a
> > >> >> point 3.125" from the center (on a chuck jaw at the OD of a 6-1/4"
> > >> >> chuck.)
> > >> >
> > >> > Ah! That sounds exactly how it now feels like when turning the
> > >> > spindle
> > >> > by hand. It sounds like I did not over-tighten it.
> > >>
> > >> O.K. Note that when I had the spindle out to change belts, I
> > >> tightened it until it fit the manual's spin test. But after using it a
> > >> while, it developed chatter. I had to go back, overtighten the collar
> > >> on the back, and then loosen it and re-tighten it after I had set the
> > >> bearings properly. :-)
> > >
> > > Hmm. I may have to do much the same, as the spindle bearing was
> > > probably too loose for years, and may need to re-adjust to its new
> > > circumstances.
> >
> > Perhaps -- but I think that I simply didn't pre-tighten over the
> > spin test point, when I should have. A bit of use pushed the bearings
> > deeper into their mounts.
> I perhaps may see the same effect. The bearings in my 5914 may well
> have walked a tad out of their mounts, and will now walk right back, > under pressure.
This does seem to be happening, and rather quickly at that. It has
become noticeably easier to turn the spindle by hand. I don't plan to
do any adjusting just yet, instead waiting to see how much it will
loosen by itself.
Joe Gwinn
Reply to
Joseph Gwinn
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O.K. I wound up the second time over-tightening it, and then loosening it until it spun the proper amount.
Good Luck, DoN.
Reply to
DoN. Nichols
I will no doubt do much the same, as I learn how much is correct.
I now have a radial-pin spanner wrench that fits and is large enough, so precise adjustment should be easier. But not until it settles a bit more.
Joe Gwinn
Reply to
Joseph Gwinn
As a data point, I was playing with a way to drive my lathe to turn my sheave bushings and the moglice coated shafts.
I made this:
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My 14.4 volt cordless drill spun up the 10" chuck effortlessly, I doubt it could have handled turning or boring loads. The big surprise was when I turned off that drill. It has a brake, it works. Damn near took my wrist off. :(
It fits in the spindle bore, uses a rubber soft plug to grip, and the aluminum part was outside bored to size on my bridgeport.
Uncle's ancient 1/2" corded drill will be used to power the turning operation. It has no brake and will need a rope over the trusses to support it. ;) Uncle is getting old.
Sorry to hijack but it is a Clausing thread :)
Reply to
I did pretty well by feel on that the first try.
Oh -- you didn't have the pin spanner before? You could turn a piece of stock bored large enough to slip over the ring and then drill it for a pin which you could slip in. Or you could press fit the pin, and then saw out about 270 degrees worth of the ring. :-)
I was lucky to be able to pick up a proper pin spanner at one of the for-sale tables at the local metalworking club meetings.
Enjoy, DoN.
Reply to
DoN. Nichols
I did consider making a spanner, but decided to get an Armstrong wrench with swinging arm, that will handle a range of sizes.
I have a large collection of random pin spanners, but none fit well, and the ones that did fit were too small and weak.
Now that I bought a wrench, the perfect one will came along for $0.50.
Joe Gwinn
Reply to
Joseph Gwinn

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