Re: Two Q's: Servo Hum and FreqMod issues

Try turning the GAIN trimpot down a smidge and see if the "rumbling"
quiets; you may have it up too high.

Mariss

--- In CAD_CAM_EDM_DRO@y..., "jbordens" <jake@a...> wrote:
> Got to questions for you wise folks here in CCED...
>
> #1 - I've got my servos working well on the bench. My maximum
> velocity is set to .60 ips, which should be within the range of my
> servo motors. When I jog, say by running a "G0 X10", the motors
> accelerate on a nice conversevative acceleration profile. When
they
> reach their max velocity they start to ruble/hum.
>
> So Q#1: is this normal?
>
> I assume this is normal because the servo drive is doing is
feedback
> loop thing, and breaking the motor to prevent it from going too
> fast. Even though I've already tuned my motors using the gecko
> osciloscope method, I want to be sure that this isn't a symptom of
> being out of 'calibration'.
>
> #2 - I'm using steppermod right now, and all works perfect. When I
> switch to FreqMod with a period of .000025 (150mhz pc) and
> STEPPING_TYPE=0 (drn, step), funny things happen. When I run a
> command like "g0 x5", the motor seeks to about where 5" would be,
> but then the motor reverses and slowly seeks backwards and doesn't
> stop.
>
> So Q#2 - any ideas why freqmod is behaving badly.
>
> Thanks to all. Have a great weekend.
> Jake