Alfred Herbert No.2 SafeTap

[Martin ConnellyParticipant @martinconnelly55370]

I have two tapping heads as described in the title that could do with a bit of TLC. They have a central shaft that is keyed so that it slides in and out smoothly and is spring loaded to a central position. It is driven by a stack of friction plates with alternate ones fixed to the body by dogs and the ones between the fixed plates rotate with the central shaft. The outer cover can be screwed further on or off to control the amount of friction between the plates to allow it to suit different thread requirements.

Despite searching on the WWW I have not found any servicing or operating instructions. What I am after is information on whether or not the friction plates should be cleaned and left dry or lubricated and if lubricated what with. At the moment the insides have gathered many years worth of cruddy muck that may or may not have been applied or may have just seeped in and may be coolant or lubricants.

So does anyone have experience of anything the same similar enough to suggest the correct course of action.

The driver for all this is that one of them was wound as tight as it would go and still slipped when cutting an M12 thread, the other one worked fine when it was tried instead.

Martin C

[Martin ConnellyParticipant @martinconnelly55370]

Servicing a tapping head -advice required

[Jonathan GarsideParticipant @jonathangarside40968]

Martin

If you searched under Alfred Herbert Saftap tapping attachment you may have more luck

Jonathan

[Clive FosterParticipant @clivefoster55965]

Martin

If the friction plates are metal on metal the clutch will almost certainly be designed to operate wet with an oil film between the plates.

Failing better information I'd clean everything up well and lubricate with a light(ish) oil. My go to for this sort of thing is Castrol Hyspin AWS 32 (or equivalent) mainly because I have a lifetimes supply for lathe and machine tool lubrication. Any lowish viscosity straight oil will do fine but I'd be chary of the additive loaded motor oil and similar variety.

Is there not a lubrication port on your tapping heads for occasional application of an oil can? I seem to recall seeing one on a tapping head that I remember as being Herbert but either ofr both parts of thgat could be wrong.

Clive

[Martin ConnellyParticipant @martinconnelly55370]

I tried the Saftap search option with no joy. Just found different models but no information. There is no oil port on the body, just a threaded hole for a locking grub screw. I'll take a few pictures to show what I have. in their current state.

Martin C

[Martin ConnellyParticipant @martinconnelly55370]

This is what I have got. The etching on the body does say SafTap as opposed to SafeTap but neither used as a search term gets any useful information from the web.

The top one has the collar I made to stop the morse tapers spinning in the tailstock (hand cut wonky slit) as they are both a bit less smooth than is ideal and additionally the tailstock has nothing to restrict the tang to a single location.. I have wiped the insides down with paper towel but will strip them completely for a proper clean, I'm just after information before the clean up goes ahead.

The collets also seem to be as rare as hen's teeth but that is not too much of a problem as I can make something that will work for sizes I don't have as they are not in an industrial environment so making them springy seems unnecessary for the amount of work they do nowadays.

The tapers are No.2 so you can get the scale from that.

Martin C

[Author]

Posts