Re: swiss turning in minature?

Graham,

Depending on how far you want to pursue this idea, you might want to
look for an older used cam type Swiss machine and think about a CNC
conversion on it. The cam machines can sometimes be had for only a
bit more than scrap value. Conversion to CNC operation would be
fairly simple, it would only involve coupling steppers or servos to
the machine's existing cam shafts.

Years ago I had a couple of 12mm Tornos cam machines. The accuracy
these machines can consistenty hold is incredible. Thinking about
the possiblilites of CNC conversion almost makes me wish I'd kept
one.

Several times I ran jobs without specially ground stock. If the
critical part features are in the length dimensions rather than
diameter then you don't need ground stock.

Doug




--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Graham Stabler"
<eexgs@n...> wrote:

>
> The parts I am making are not very long so I don't think a steady
> would be possible. I really just wanted to take advantage of the
> high rigidity for maximum precision. I don't have a suitable

lathe

> so whatever I do may have to be scratch built.
>
> Precision ground stock may not be a problem and I am sure I would
> only need one size. I have some motor shafts for example that are
> ground but not hardened.
>
> I may try a few experiments to see if there is any mileage in this

at

> all and if not it may be easier to build some sort of grinding set

up

> where machining forces are small and precision can be got that way.
>
> Thanks for the advice,
>
> Graham
>
>
>
>
>
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "Marcus and Eva"
> <implmex@a...> wrote:
> > Hi Graham:
> > I would still do it on a conventional lathe equipped with a
> travelling
> > steady.
> > Whether the headstock moves or the carriage moves is really not
> relevant as
> > far as the requirements of this job are concerned.
> > Swissturning is a high volume production process...it's just too
> difficult
> > to get it going with a cobbled setup.
> > The Devil is really in the details with this process, but

turning

> on a
> > normal machinists lathe will do this job easily.
> > A good part of the reason that Swissturning is successful as a
> process, is
> > that it's possible to put a lot of tools into the work
> simultaneously, but
> > you don't need to do that.
> > I'd abandon the idea.
> > Cheers
> >
> > Marcus
> >
> > ----- Original Message -----
> > From: "Graham Stabler" <eexgs@n...>
> > To: <CAD_CAM_EDM_DRO@yahoogroups.com>
> > Sent: Monday, May 12, 2003 8:53 AM
> > Subject: [CAD_CAM_EDM_DRO] Re: swiss turning in minature?
> >
> >
> > >
> > >
> > > Dave, it is more the machine that I want to minaturise than the
> > > parts. The roller I mentioned was to be about 1mm in diameter

but

> > > other parts may be smaller and accuracy is very important. It

is

> for
> > > a 100:1 planetary friction drive for a 4mm (that's not the

shaft

> but
> > > the diameter) motor.
> > >
> > > Marcus, thanks. It sounds like you know your stuff. I had
> wondered
> > > about using just a brass clock bushing that would be replaced
> often
> > > and held in a ball race. Then I could use say silver steel as

a

> > > blank as it is fairly accurate. I can't help but feel there

must

> be
> > > a dirty solution. Maybe a makeshift airbearing. Make or

obtain

> an
> > > accurate bush, bore out some of the central section and apply
> > > compressed air through a cross drilled hole. This would still
> need a
> > > good blank material. I can buy hardened ground stock in the

form

> of
> > > drill blanks but are unhardened blanks available?
> > >
> > > It sounds as if this might not be the simple solution I had

hoped

> > > for. Darn.
> > >
> > > Cheers,
> > >
> > > Graham