Re: [CAD_CAM_EDM_DRO] Re: Linux EMC, Stepper motors only move in one direction?

wwashington2k wrote:

>--- In CAD_CAM_EDM_DRO@yahoogroups.com, Jon Elson <elson@p...> wrote:
>
>
>>Have you looked at these signals with an oscilloscope or DVM?
>>
>>
>
>I'm using a 16 channel logic analyzer to look at the signals.
>
>
>
>>Which motion module are you using?
>>
>>
>I'm using freqmod.o.
>
>

Ahh, then what do you have STEPPING_TYPE set to?
and also, what is PERIOD set to?

In the axis section, what are DEADBAND, BIAS, SETUP_TIME and
HOLD_TIME set to? What is the clock rate of the logic analyzer set to?
(If it is too slow, it could be missing narrow step pulses.)

>
>
>> Are you using backlash compensation?
>>
>>
>
>I don't know. I know what backlash is, but I don't know how it
>relates to the emc.ini file.
>
>
>

There is an optional line, BACKLASH = n.nnn in the .ini file for each
axis. This sets the amount of backlash compensation that will be put
in when that axis reverses direction. Wrong values can drive the system
crazy, and some combinations of other parameters have caused the
backlash compensation to do really ODD things. If it is non-zero,
set all of them to zero until all other problems are solved.

Jon