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

Marketing prospective?
There are some sherline type machines out there
that include toolchangers, those machines
cost about $15000.- they are mostly bought for
educational and industrial purposes.
So there is a market, however to sell to
the Hobby market you have to be a lot cheaper to
make this attractive.
So price will be the key question here, what can
you make it for?
Most Hobby guys would probably consider this a luxury
item, but then if its really cool you may be able to
bank on the bragging rights.:-)

For the Mill/Drill market this would be a much tougher
sell, because a 1/2 or 5/8 shank limitation would not
go over well with the brought majority.
But there may be a smaller specialised industrial market.

Bottom line is to sell to the industrial market your
toolchanger has to be very good.
To sell to the Hobby people it has to be cheap.

just my personal opinion
Good Luck with your venture


--- In CAD_CAM_EDM_DRO@yahoogroups.com, "ballendo <ballendo@y...>"
<ballendo@y...> wrote:

> 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