RE: Van Norman #12 Milling Machine

You can use a regular air cylinder (with adequate stroke) and get nearly
linear force by attaching an accumulator bottle to the inlet. The bottle
can be an old 2lb fire extinguisher bottle or home made from one foot of
three inch pipe. A two inch air cylinder will give 314 pounds of lift at
100 psi. Another solution is to use a regulator on the cylinder and no
accumulator.

Doug

> -----Original Message-----
> From: Bertho Boman [SMTP:boman@...]
> Sent: Monday, January 24, 2000 8:26 AM
> To: CAD_CAM_EDM_DRO@onelist.com
> Subject: Re: [CAD_CAM_EDM_DRO] Van Norman #12 Milling Machine
>
> From: Bertho Boman <boman@...>
>
> You would need a LONG cylinder so that the relative length do not change
> too much.
>
> I have been playing with the idea of using very large and LONG springs for
> the same reason.
>
> Another possibility is to use a short spring or air cylinder but let it
> work over a variable pitch pulley so the resultant force
> is linear.
> Bertho Boman
> ===============================
>
> > From: PTENGIN@...
> >
> > In a message dated 01/23/2000 8:26:26 PM Hawaiian Standard Time,
> > jmelson@... writes:
> >
> > << Unfortunately, those would be BIG gas springs. Maybe, one could
> come up
> > with old oleo struts from aircraft landing gear. That would be about
> the
> > right size.
> >
> > Jon
> > >>
> > Jon,
> >
> > How do they keep the force more or less constant on those gas
> springs? I
> > also considered pneumatic cylinders. However, like a regular spring, the
> rate
> > changes depending on where in the travel you are. I considered a
> regulator
> > but then you need a compressor to admit when low and the regulator to
> dump
> > when over pressure. Maybe if we got a really large cylinder and ran low
> > pressure.....
> >
> > Peter
> > THRD, Inc.
>
>
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