Tapping holes while material is still clamped to my mill table?

[ptjw7uk]

Hi HankMcSpank
I dont think the cnc cutting of threads is remotly like hand cutting a thread in that the cutter is much smaller than the diameter of the thread being cut plus the cutter does not have a spiral on it just the thread form at the correct pitch. The cutter is then advanced into the hole centre moved to the edge the required depth and then the cutter is traversed around the hole whilst advancing at the required pitch so the cutter can whizz round as fast as is needed.
Hope decription shows how it should work, I think you are getting confused with power tappers.
Peter

[HankMcSpank]

Thanks Peter.

I've just had an Ebay seller who suggested something like this (a small chuck on a hex shaft)...

http://cgi.ebay.co.uk/CK-1-4-Hex-Sha...item5ad37c932c

which while a little 'cluncky', I suppose will get me away!