Re: [CAD_CAM_EDM_DRO] Re: Sherline Auto Tool Changer

James,
Peter,
one hurdle to consider is the Sherline MT 1 taper is not self releasing.
In fact it takes quite some effort to extract tooling. Unscrewing the
"drawbar" and then knocking out the tooling. The spindle has to be locked
to do this as well.
The machining centers at the tech school I attend/work at are all cat40.
A fat tapered, self releasing industrial standard. Held with an air actuated
claw pulling on a knob at the top of the holder.
At home, I have a Rockwell V/H machine using the little NMTB30 taper,
but this is still way too big for the Sherline. The drawbar is 3/8-16.
Using all sherline threaded nose holders may be an option, but the extraction
is still tough to solve, not to mention having each tool pre set.
RichD

James Owens wrote:

>
> Hi Peter,
>
> This is the bit I'm asking about. I'm a where how manual change millers hold
> the tooling/holder in place. I have a Bridgeport type machine. The question
> is how do auto-changers, when they are fully automatic, hold the tooling in
> the spindle. I can change a tool in a few seconds but I have to be there to
> do it. So if it is necessary for me to tighten a draw-bar why use an
> auto-changer when the tooling held in a lazy-susan would do?
>
> > The sherline tool holder simply screws into the spindle on a high
> > precision thread & shoulder. There's a 3mm hole in the tool holder
> > which allows you to locate in the holder to unscrew it. Sherline
> > claim that as the thread and location hole for the cutter shank are
> > created without removing the piece from the machine, that the
> > accuracy is very high !
> >
> > I know that full size CNCs use a draw bar to pull the tool holder up
> > against the taper and locate it onto a dog, but I am trying to think
> > of a way of using the existing available stuff.
> >
> > Another way would be to make an adaptor to fit the Spindle and then
> > make special tool holders to fit the adaptor.
>
> Regards,
>
> Terry