Re: Threadmill

--- In CAD_CAM_EDM_DRO@e..., Alan Marconett KM6VV <KM6VV@a...> wrote:

> Hi John,
>
> Thanks for posting the threadmill pix. So the threadmill spins in

the

> collet, and the part makes 1 rev, and moves up one pitch? Looks

like

> the "thread" part is in holder at a slight angle? Is this

something I

> can grind out of a tap and try myself, or do they make a threadmill
> small enough for a Sherline?
>

Alan,
Nearly,
The thread mill spins in the collet and then feeds radially into the
work to full depth. Once at full depth the table then circular
interpolates to create a full circle. As this is happening the Z axis
drops equal to one pitch. This then cuts a thread equal in length to
the number of teeth on the cutter.
I can't see any reason why you can't grind all the flutes off a tap
except one to use a thread mill.

They actually make a tool called a 'Thriller' [ No relation ro
Micheal Jackson <g> ]that drill the tapping hole then moves out
radially and mills the thread in one interpolation. These can even
counterbore or countersink in the same operation.
Just don't ask how much they are. Used a lot in commercial shops with
multi driven heads. Can put 6 spark plugs holes into a head in about
3 second.