CAD CAM EDM DRO - Yahoo Group Archive

Re:EMC, Geckos and Sherline

Posted by Ray Henry
on 2003-02-26 17:27:53 UTC
(comments mixed in)

>    From: "moultim <moultim@...>" <moultim@...>
> Subject: EMC, Geckos and Sherline
<s>
> 1. Is the emc.ini file where all the configuration information is
> stored?  I cant find steps/inch, and direction polarity and such, so
> it cant be.

Uh. Yes. The EMC does not necessarily work in inches it works in units
which you can define as inches if you wish.

; LINEAR_UNITS = 1
LINEAR_UNITS = 0.03937007874016

The one indicates mm the .03 is the conversion factor, For inch you will
need to set the .03... value in [traj] and in each [axis #] If that's
done you need to set some values in each axis for the number of pulses
per unit.

If you are using steppermod then you would change the first value in

INPUT_SCALE = -4000 0

for the number of pulses that EMC needs to spit out for each unit
traveled.

If you are using freqmod you will also need to set output scale to the
same value.

OUTPUT_SCALE = -4000 0.000

Yes you guessed it, the sign of the number is the direction.

If you use freqmod you will also have to tune the axis to the motors and
loads that you have on your system. Tuning is done with the P I D FF#
variables in each axis. There is some info on this in the handbook and
in the FAQ.

> 2. Do I have to use the bit order typically used in EMC?

If you mean the definitions of each parport pin, yes unless you are
willing to edit the parport definitions in emc/src/emcmot. That would
require a compile of the system after your edits.

> 3. What do I need to implement encoder feedback?

smdromod will take the encoder feedback from a Kulaga/Mauch dro card and
use them as the feedback for step pulses. If you do this, input_scale is
the pulses per unit going out to the motors and output_scale is the
number of pulses being returned by the encoders for a unit of movement.

> 4. What mode should the parallel port be in?

Doesn't matter for the standard output of the emc. Any parport mode will
tickle the pins in the fashion that EMC does.

> and finally:
>
> 5. If you have a similar configuration, could you email me your
> configuration files?

My mini.ini is included with the BDI's. It comes very close to a working
system for my Grizz mill. If you want I could try to work up something
for a traditional Sherline. What Gecko are you using?

Ray

Discussion Thread

Ray Henry 2003-02-26 17:27:53 UTC Re:EMC, Geckos and Sherline