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 dissipate.

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.

Thanks,

Jon

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.

Stan

Reply to
stans4

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!

Jon

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.

Jon

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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