Engraver taper query

I have been given a quantity of tapered engraving cutters without the engraving machine.

Can anyone tell me the machines they fit and/or the details of the shank taper?

The shank taper has small diameter of about 0.160" and large diameter of about 0.215", with an overall length of the ground taper varying between 0.720" to .780" on those that I measured. see pics.

Thanks

Dennis

Edited By Dennis WA on 29/02/2012 13:50:56

Dennis these are specific taper cutters for machines like Taylor Hobson or Alexander and Deckel engravers.

They reqiure a special tool grinder either with a diamond wheel or white silica.

Special toolholders are provide with the machine so that the relief angles are correctly ground.

Other than that I can see no use in normal workshop tooling.

Clive

Clive....thank you. I accept that these engraving cutters do not really fit into the scope of our workshops.

I am curious to identify the taper (I cannot find a reference in my handbooks) and if possible the manufacturers that used it. These cutters came from the estate of a man who had worked for Marconi Instruments in the St Albans area and I imagine they were used for engraving brass dials.

From what I can find out on the internet, the modern CNC-type engraving machines do not appear to use taper shanks.

Dennis

It is almost certain MI would use a mainstream quality engraver like Taylor Hobson. I only have one T-H cutter and it measures very close to what you quote and the notch above the flat is used on their cutters but I don't know if that is exclusive to them.

Reminds me I must check on my engraver friend from the nearby Marconi Defence. Just hope it's not the same guy.

Bazyle, the notch on the cutter is used with a 'V' tool to lock/tighten cutter into taper in the headstock.

It is also used in reverse to remove a cutter.

In use the cutter is also retained with a domed collar and a threaded head nut that is finger tightened.

Clive