Re: Threadmill

Thanks John,

Seems like a lot to cut in one interpolated circle! That would be full
depth of the thread in one cut! A tapered tap would "work up" to full
depth over the length of it's taper. I suppose a threadmill made from a
tapered tap could do the same. But then the cutter is TURNING. Guess I
answered my own question! And the tool moves helical, around AND in!
Don't need a rotary table with CNC.

Alan KM6VV


John Stevenson wrote:

>
> --- 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.

Don't you need 8? ;>)