RE: [CAD_CAM_EDM_DRO] step/dir servo (Gecko drives)

> > disk (Required too high a pulse rate for it to be
> successful with EMC, but
> > other programs may give different results), 400, 250, and
> 200. This is the
> > slots and all were being used as 4X giving 4000, 1600, 1000, and 800
> > effective steps per revolution. The parameters in EMC were
> set for 10 motor
> > rotations = 1" table motion. If you were using a belt drive
> like are then
> > the 1000 slot encoders would probably work fine and the 200
> slot may have
> > too coarse a resolution.
>
> I am a bit confused at what you mean above. Wouldn't the use
> of a belt drive (2:1 reduction for example) mean that a 200 slot
> encoder would give 1600 effective steps per each revolution
> of the leadscrew instead of 800? In other words... 2
> revolutions of the
> motor shaft with the encoder attached would = 1 revolution of
> the leadscrew. If this is true then I am confused by your last
> statement above.
>
> Thanks
> - Dan

I hate when I read my own posts and they just don't make the sense they did
when I wrote them <g>

I was trying to relate the counts to motor revolutions, not leadscrew. You
are correct that with a 200 count disk and a 2:1 belt drive you would have
1600 counts per leadscrew revolution. On the belt drive I was trying to
convey the idea that if you are using the belt to drive the table (or
gantry) directly as in Art's router you could probably use the 1000 count
encoders as you don't have the reduction effect of a lead screw. Should have
been more clear that I was not referring to a belt reduction to a lead
screw.

Tim
[Denver, CO]