Re: Sherline Auto Tool Changer (mill/drills too!)

Peter,Sherline CNC'ers, mill/drill CNC'ers,

I've got one worked out that I'm positive will work. Not too
difficult to make, either...

Now I'm wondering what someone would be willing to pay for an 8 tool
autochanger for the sherline 5000 series mills? Is 8 tools enough?

Max diameter of toolshank is 1/2, but limiting this to 3/8 would
prob'ly make things less expensive overall. Is 3/8 shank limitation
okay? Or must 1/2 shank tools be accomodated? What (shank)size
holders do you NEED?

Shop air would be needed, so is requiring an air compressor okay?

Do you want to buy it complete, or make it from plans/kit?

What would you be willing to pay for a complete, bolt on unit?
A kit of parts?
Plans?
Which of these three options is most "real" for you?


If you make it, you will need the sherline lathe also (or some other
lathe of similar capability) Is this going to be a problem? If so,
would you be interested if the kit had the lathe parts already made?

BTW, no mods to the mill need be made... This is a bolt-on-and-go
item.

The unit I have designed will scale to mill/drill operation as well:

Same questions as above, but max shank diameter can easily be 1/2. Is
5/8 necessary ?

The lathe parts could probably still be made on a sherline, but a 7x
or 9x size would make things easier...

So sherline and Mill/drill users, please let me know what your
answers to these questions are???

Thank you in advance,

Ballendo

P.S. Reply offlist, if you want to preserve your "lurk status" here<G>






--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Peter Cruickshank
<crankshaft_sg@y...>" <crankshaft_sg@y...> wrote:

> Ballendo;
>
> Now, we're getting somewhere !
>
> Hmm, you're right, the sherline collet is 'handy' cos it ready made
> and seems like the logical choice, but the spindle locking and
> undoing the holder is a problem, you're right that it would be very
> difficult to undo, that was at the back of my mind, I guess I just
> did not want to acknowledge it !!!
>
> The current morse 1 taper limits the collet and cutter size as it
> assumes that the cutter will locate inside the spindle, but there's
> no reason why an adaptor can not fit on the end on the spindle and
> interface to a quick change tool, I think there would still be
> sufficient Z travel even with an adaptor on the end of the spindle.
>
> We have gone through the first rule of troubleshooting which is to
> elimante what it isn't (can't be done) now we only have to find

what

> can - so it should be plain sailing from here on in :-)
>
> PeterC
>
>
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "ballendo <ballendo@y...>"
> <ballendo@y...> wrote:
> > Terry,
> >
> > Most fully automatic changers use a similar technique.
> >
> > Tools are held in vee-shaped non locking single taper holders.
> There
> > is a retention knob at the top of the holder, which is the small
> end
> > of the vee shape. Fingers inside the spindle are designed to
> capture
> > this knob and pull it upward (often using belleville washers for
> > the "drawing in" force). The interior of the spindle is shaped so
> > that thes fingers lock in a failsafe way (as long as the

retention

> > knob doesn't break of where it screws into the holder... Yes, it
> > happens).
> >
> > To change tools, hydraulic or air pressure is used to compress

the

> > belleville washers, which drops the fingers a bit, which allows
> them
> > to come out of the failsafe recess, which lets them release the
> > retention knob, which allows the holder to drop out (into a
> > waiting "transfer arm", or into the lazy susan itself.
> >
> > Hope this makes sense,
> >
> > Ballendo
> >
> > P.S. Do a search of "CAT 40 holder", to see one of these holders
> >
> >
> > --- In CAD_CAM_EDM_DRO@yahoogroups.com, "James Owens"
> > <wotisname@l...> 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