Re: Values for Calulating Motor Sizing

I can't offer more than my approach.

Clamp down a piece of stainless and an 1/2 inch end mill. time how
long it takes you to take a cut of an inch or two. That would be low
speed.

Clamp a piece of aluminum and a flycutter and spin that part along
the table and time it for a few inches. that would be high speed.

Halving low speed and doubling high would give you what your personal
machinging envelope would be.

Other basic math might be to figure the cutter speed RPM for the 1/2
inch end mill, and how much depth of cut should be taken in all
materials. as an example IF you ran the spindle at 1,000 RPM and
took a 0.0025" depth of cut on a 4 flute end mill, (0.01" per rev)
you would need to move the table 10 inches a minute.

Is that math right ? 0.01" per rev, 0.1" per 10 rev's, 1.0" per 100
and 10 inches per minute at 1,000 RPM. Substitue real numbers and
not the ones I made up. Most catalogues offer recomended cutting
speeds and depth of cuts.

Hope that is of some help.

Dave

--- In CAD_CAM_EDM_DRO@y..., "caudlet" <tom@t...> wrote:
> --- In CAD_CAM_EDM_DRO@y..., "natchamp_87" <mark@h...> wrote:
>
> > What would be a low/med/high IPM for a CNC milling operation? I
> will
> > be mosting doing aluminum with some steel. What IPM is slow,
fast,
> > etc. I'm shooting in the dark at this point.
>
> Time to pull out the Machinists Handbook...woops wrong egroup!
> Cutting of different materials is done by surface feet per minute.
> Sounds simple but it is a combination (in the case of a mill) of
the
> diameter of the cutter from which you can get the circumference.
The
> RPM combined with the feedrate determines the SFM. Then you have
> different rates for HSS or Carbide tools. See what I mean?>
> > What is a good Lbs value? Is this suppose to represent the
weight
> of
> > the table or force required to move the table while cutting, or
> > both? I'm not a mechanical engineer, or any other type, so I
need
> a..
>
> The force is the frictional forces of the moving parts (table,
etc)
> plus the amount of force the actual cut requires and is based on
your
> machine and what kind of material you cut and how deep your cuts
are
> with each pass.
>
> I know this is not the answer you want but sometimes you need to
> understand the basis of the question. Some others can give you
rules
> of thumb about speeds and feeds.