Clausing 5914 VariDrive Wobble

Well, I today took the bottom pulley assembly of the varidrive apart,
the part that is attached to the motor shaft, and that wobbles badly.
The wobble is not caused by the plastic bushing at all. It and the
green coating are just fine. (The green coating did have a few score
marks parallel to the shaft, probably from some grit that somehow got
inside.)
I knew I was in trouble when I went to loosen the two 1/4-20 setscrews
that fasten the varidrive pulley to the motor shaft, and found that both
were already loose. And then I noticed that the square key was a bit
cockeyed. Removing the pulley took considerable force, requiring a
prybar against the motor housing. The keyslot on the motor shaft
flares, becoming wider as one goes away from the motor housing, and the
metal was mushed outward. The slot in the pulley doesn't look too bad,
except for the busted-off corners.
The motor shaft does not appear to be bent, but I should verify this
with a dial indicator.
I assume that the pulley was a push fit on the motor shaft, when it was
young. Over the years, the setscrews loosened, and things drifted,
unnoticed. (Or someone forgot to tighten them after a repair.) The
whole assembly seems to have moved out about 1/2 or 3/4 inch, enough so
the end of the varidrive assembly was hitting the lathe cover, and
chewed a hole in it, so one could not properly install the cover. I
wondered about that when I got the lathe.
I filed away the obvious bumps on the shaft and the bore, but the pulley
still will not go on the shaft without far too much force. Tomorrow, I
will fit pulley to shaft using blue highspot and a small file, slowly.
I suppose locktite may be needed as well, as the motor shaft and/or bore
in the pulley is probably slightly tapered, and would fret in operation.
Before I took it apart, the pulley was solidly albeit crookedly stuck to
the shaft.
Anyone have any other ideas?
Joe Gwinn
Reply to
Joseph Gwinn
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Joe
Wish I would have seen this before I went to the shop today. I did find the spare plastic bushing, it's a red or maroon plastic and I'm guessing that it's the piece for the movable motor pulley half.
If the damage is to your fixed pulley half and not to the motor shaft I do have the complete motor pulley assembly (I haven't tried to remove the fixed half from the motor shaft as of yet). I also have the original motor but it probably needs new sleeve bearings, side to side play is undetectable but it probably has about 5 thou vertical play, as a guess. It's heavy and shipping would hurt.
I have most all the other drive and hydraulic parts available as well.
If it turns out you need these other parts we'll work something out. I need alittle something for them to help defray VFD conversion costs:)
I won't have a chance to get back over to the shop again until next Friday.
Regards Paul
Reply to
Paul
More of a brownish if it is current stock.
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Fits either pulley after you bore it to fit.
Wes
Reply to
Wes
Well, thanks for finding it. I'm sure it will find a home, given how common this problem is, so the effort will not have been wasted.
The bushing in the lower pulley on my machine is brown. Perhaps someone before me replaced the bushing. And forgot to tighten the setscrews.
My understanding is that upper and lower pulleys take the same bushing. In my manual, only one part number (049-088) is given.
I wonder what the green coating is. Acetone makes it sticky, so it is not teflon. Nor does it feel like teflon.
It turns out that the damage is largely to the end of the motor shaft, with little damage to the pulley. As mentioned in another posting, after some hi-spotting and careful filing of high spots on the motor shaft (right near the keyway, which had become funneled and bulged), it went back together properly, and there is very little residual wobble.
Is there any way to oil the sleeve bearings in the motor? Or a need to?
That would be fair, although I don't yet know what I will need. Who knows what else I will find as I learn this machine, repairing things.
Joe Gwinn
Reply to
Joseph Gwinn
My specimen definetly has a reddish hue to it. Can't say as to its vintage as it came with the machine, in a box of misc parts stashed in the cabinet under the tailstock end.
Paul
Reply to
Paul
No idea, there was no greenish stuff in evidence when I took that pulley apart.
Good for you.
Usually sleeve bearing equipped motors have some sort of lubrication means, oil cups or grease zerks. There's zerks on the old motor, it still coasts for some time when given a good spin by hand.
One thing to check is the balance spring under the speed adjuster, it's a flat clockspring in a housing. Mine was broken when I got the machine, I 'fixed' it which lasted for awhile until it let go again. The speed adjuster works without it but requires more force to adjust. I acquired a used one via ebay but hadn't got around to installing it when a good deal on a VFD came along.
Paul
Reply to
Paul
Green loctite?
Gunner
"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner
Reply to
Gunner Asch
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I've heard it referred to as teflon by others. I wish some one that is familiar with anti friction coatings could identify what this coating is.
The typical repair if this coating is bad is to coat with Moglice 1000 Semi and then turn back to size. Followed by machining the Delrin AF (I think) bushing to fit.
Wes
Reply to
Wes
I wouldn't think so, as locktite needs to be confined between metal surfaces to cure, while this stuff seems to have been applied as a paint. And acetone makes it sticky, which I don't think happens with cured locktite. Is locktite slippery? I don't recall that it is.
Joe Gwinn
Reply to
Joseph Gwinn
I forget when your machine was made. Mine was made in 1972. Perhaps the green coating was a later (or earlier) addition.
I suppose we could cheat -- call Clausing and ask.
I didn't find any obvious places to put oil or grease. Perhaps they used permanently lubricated ball bearings. The motor does turn freely, taking some time to coast to a stop.
The balance spring seems OK. I'm still bleeding the air out of the hydraulic system.
Joe
Reply to
Joseph Gwinn
I've got it written down somewhere, but 1967 comes to mind. Looking at the picture of the green coating someone else posted I can say if mine had that coating its long gone, there's no green in evidence. Either it never had it, or someone removed it in an earlier repair, or it now looks just like steel:) I would think if was just worn away there would be some remaining somewhere.
Paul
Reply to
Paul

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