wierd problem with tapping head

Hello, all,
I have a Procunier model 15000 "CNC" tapping head. This is just
a set of clutches for 1:1 forward and 2:1 reverse, with no
overload clutch, leadscrew or other stuff. It depends on the
approximate sync between spindle RPM and quill feed to run the
tap in and out.
When I got it it acted strange, with the clutches grabbing
erratically, so I opened it up and found it FILLED with WD-40.
I figured that wasn't a good solution for cork clutches and
cleaned it out as best as I could. I was guessing that the
previous owner (yes, this was an eBay purchase) had a problem
with coolant getting into the works. It ran much better after
removing the WD-40, but I still had occasional grabbing
problems, like both clutches would engage at once and lock it
up, or it would start running real hot. I would find drops of
what appeared to be liquid water on the clutch material.
Anyway, when I tried to use in yesterday, it was solidly frozen.
I pulled it apart and it was MASSIVELY rusted inside! All
exposed steel except the gear teeth were covered with a thick
layer of rust! I scraped the black/grey rust off the cones the
clutch grips against, and removed some of the other rust in
non-critical areas, and lubed up the bearings at both ends of
the tap output shaft, and got the job done. I then disassembled
it and left it open, hoping that any remaining water would
I NEVER use this unit with coolant, only brush-applied Alum-Tap
tapping fluid, which has no water in it (napthenic oil and
Stoddart solvent, according to the label) and the unit has been
protected from any possible contamination with water when
stored. Where the HELL is this water coming from? The only
reservoir I can imagine is the clutch material, but that can't
hold a large amount of water, can it?
I'm thinking of baking the part with the clutch lining in an
oven for a day at 70 C or something to get the water out of
there. Anybody ever run into anything like this, or have any
suggestions about how to stop this nonsense? I don't think I
can find enough room inside to put a dessicant pack in there, or
I'd do that.
Reply to
Jon Elson
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Got a bell jar and vacuum pump? A few days under good vacuum may dry it out. Vacuum+dessicant would be even better.
Cork is porous, might be the previous owner added the WD40 to displace the water, rather than for lubrication. Might be easier to replace the cork than to dry the stuff out completely. I'd suggest a soak in some alcohol except I wouldn't know what the cork was bonded with, you might end up with loose bits instead of dry ones.
Reply to
I think a week in the open air in wintry St. Louis will do wonders to pull the water out.
Oh, I am sure that is true. Might be easier to replace
I'm also not sure the material really is cork. I kind of remembered that, but it doesn't look like cork now, but more like some synthetic stuff. But, maybe it is coated with steel rubbed off the cones.
This thing is a double cone, so it could be very hard to replace the friction material. I know Procunier sells repair parts, but their collets are $82 each, or something, so I haven't even considered asking what this will cost!
Reply to
Jon Elson
As a young man I worked at a gunshop. Pretty regularly we would get a firearm whose owner thought poking the spray tube of a can of WD40 in a hole and pressing the valve was the same as cleaning and oiling. The actions would be filled rusty jello. They should only sell that stuff to professionals.
If, by odd chance, your clutch is the same as the one they use on a 2E, (1 1/16" thick, 2 5/8" dia, die cast hub w 1/2" bore) drop me a line.
I have a couple spares I snagged on ebay a fey years back.
Paul K. Dickman
Reply to
Paul K. Dickman
The cork clutches are supposed to run dry? I restored a 1912 Thomas Flyer that had a cork clutch in an oil bath.
Reply to
Stupendous Man
I don't even know what a Thomas Flyer is, and I think these clutches are not really cork, but some sort of synthetic.
Procunier says to only lube the gears very sparingly, to keep it off the clutch.
Reply to
Jon Elson
Hudson automobiles and many British motorcycles of the '50's used cork clutches in an oil bath. I have recorked many Triumph clutches. So oily cork does a useful coefficient of friction although it is lower than dry cork.
Don Young
Reply to
Don Young

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