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

Hi Ballendo;

Well, if you ask for my wishlist it would be this..

We are (all ??) hobyists, so to make it ourselves would be fun,
challenging and of course much cheaper, so I would of course opt for
the plan with the option to buy certain parts which we can't or
don't want to make !!

I live in a small apartment in Singapore, and one thing I don't have
and can't have is an air compressor running in here, I would be out-
of-here in minutes if I had compressor humming and vibrating my
neighbours, so air is out of the question for me unless it's a small
12 volt compressor with no storeage cylinder !

Other that that, a 3/8" shank, (well actually a 10mm shank for
everyone but the US !) would be more than adequate for the sherline
and the work which will go through it.

8 Tools is more than enough, 6 would be enough for me, I could
probably get away with less than that if it were to simplify or
reduce the cost !

Hope that helps, I understand that you may want to protect your
design, but I would be interested how generically you have planned
to go about this ??

Cheers !

peterC

--- 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