Re: 300 IPM - machine resolution and encoder slots

--- In CAD_CAM_EDM_DRO@egroups.com, "Carlos Guillermo" <carlos@v...>
wrote:

> I think a 400 slot encoder with a 5 TPI screw should give you:
>
> 400 X 4 (quadrature) X 5 (rev/in) = 8000 counts/in
>
> This is equal to a res. of 1/8000 = .000125 counts/in
>
> Am I missing something?
>
> Also, as far as steprate requirements, for 300 in/min (5 in/sec) at

this

> resolution you'd need:
>
> 5 in/sec X 8000 counts/in = 40,000 steps/sec
>
> I know of several PC controllers that can do this easily, even up

to about

> 100,000 steps/sec. That would allow 1000 slot encoders (w/

quadrature) and

> 5 TPI screws to run at 300 in/min with a resolution

of .00005"/count (20,000

> counts/in). Can somebody double-check this for me?
>
> Carlos Guillermo
> VERVE Engineering & Design
>
>
>
> >Carlos,I had problems trying to get my 486 50 to do 20.000 step/s.

in the past,(on my sherline,23tpi screws)moving 2 axis at the same
time.It would do it ok moving one axis at the time,but 2 axis it
losses steps.T'll this day I don't know if was the computer or the
controller(Camtronic's) or software.Iwas forced to work with 12"/min
maximum.
That happens when cutting circles for exemple.Industrial cnc's also
have a limit on circular interpolation of about 50 to 100"/min.