Re: [CAD_CAM_EDM_DRO] Encoders for the G320

arturodu wrote:

>Dear Sirs,
>
>The doc´s from the G320 say I need an encoder of at leas 200 lines.
>I'm unsure on how that relates to CPR, I guess it is the same. If
>it is the case, I guess I should just go for the highest for better
>resolution. Is this correct?
>
>

CPR is an ambiguous acronym. it could mean counts per revolution, or
cycles per revolution.

Most encoder manufacturers rate their encoders in cycles or pulses per
revolution. When reading
all transitions of a quadrature encoder, you get 4 times that number of
counts per rev.

But, unless you know the meaning of the C in the CPR, you don't know
which of these
measurements is being described. Mariss' description of 200 lines is
clear. Lines is the same
as cycles, it refers to the stripes on the encoder wheel. So, he
suggests a minimum of 800
counts/rev. A 250 cycle encoder will give 1000 counts/rev, which works
out nicely for
computing the steps/inch (or mm, etc.) But, within reason, get what is
available. You
may not want to go too high, as some software has trouble producing high
step rates.

Jon