Re: Low cost Servo Controller

Hi,

I have been 'listening' to this group with great interest for a couple
of weeks now, ever since finally getting EMC to run on my mill, and
have a couple of quick questions I'd like to put up.

Firstly, as 99% of my work is in metric I have been trying to set it
up for metric defaults. I have practically managed this now, though I
have to issue a G21 before anything else. My problems is that
now, if I give a G20 to put it into imperial mode it does move
imperial distances with imperial speeds, but the screen display
stays in metric ie. G0 X1. results in a move of 1 inch and a display
of X = 25.4000. Are there any configurational changes I can make
to correct this?

Secondly, the jog increments have scaled down into the metric and
are now 0.1 0.01 0.001etc of a mm ....to small to be of any real
use. Is there any way of adding a 1.0 and a 10.0 to the list?

I was intrigued to read of the LM629, and have already downloaded
the data sheet. It looks quite impressive but with some limitations
that others have already stated. Has anyone looked at the SGS
L6515 ? This is a dual servo motor driver in one package, has
encoder, tacho and current feedback, PWM output, supplies a
decoded step and direction signal to it's host from the encoder and
will auto-lock on 1 encoder pulse when told to stop. At $13ea they
seem to good to be true! The downers as I see them are the 6 bit
velocity control and the lack of information on how to calculate the
values of the external components.

Regards

Pete