Re: re:cleaning, lovejoy, black box tach, linear scales, making pulleys

Hi,

A tachometer is used to sense motor speed. In the G320, motor speed
is not sensed so neither tachometer or pulse averaging is used.

The G320 is a position servo. The PID loop adjusts torque to maintain
a "zero" difference between the commanded position and the motor's
actual position. If the command position itself is moving, such as
when STEP pulses are issued, then the drive will follow the moving
position with "zero" error. The speed will exactly equal the STEP
pulse rate.

For those who are interested, I can post a .pdf to the "files"
section a block diagram of how the G320 works if asked.

Mariss
Geckodrive Inc.

--- In CAD_CAM_EDM_DRO@egroups.com, Jeff Barlow <jeff@b...> wrote:
> Ballendo, Jon, et all,
>
> Mariss seems to make the Gecko 320 get along without a tach, though.
> Hope he jumps in here.
>
> Jeff
>
> On Tue, 28 Nov 2000 08:59:39 -0000, Ballendo wrote:
>
> >
> >As explained in a previous thread: At slow speeds, the tach is
more
> >accurate and reads direct. The pulse average-ing (to derive speed)
> >suffers from data starvation. (not enough pulses per unit of time
to
> >ACCURATELY reflect the "real world" happenings at the axes)