Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Robhi on March 02, 2013, 01:30:49 PM

Title: Gecko 320 , Servo
Post by: Robhi on March 02, 2013, 01:30:49 PM
 :) Hi every body,

I would like to use gecko 320 for servo, but there something that I can not understand, so I need your help please.

it is written that before testing the gecko drive, we should turn P I D T trimpot to 11 O'clock. Could I have your help please, with more details, please?

thanks

Robhi
Title: Re: Gecko 320 , Servo
Post by: jonny quest on March 02, 2013, 06:12:12 PM
Don't worry about it to much.

There's gain, damp,  and limit.

Turn your limit up to about 75% of full, gain and damp to 50% of full.

Then you'll run your machine and tune servos in by listening and feel.

There's no other way to describe it then to just do it yourself.

Try and get your limit to full. That way your servos will be getting max Volts.

Title: Re: Gecko 320 , Servo
Post by: Robhi on March 03, 2013, 09:02:50 AM
Hi, thanks for your replay,

so there is no problem if I turn it badly ? i.e, if I turn it more or less than 75 %

thanks
Robhi
Title: Re: Gecko 320 , Servo
Post by: jonny quest on March 03, 2013, 11:01:14 AM
That's what I was scared of also.

There won't be a problem... unless you leave it there with a bad tune.

Google CNCcookbook servo tuning
Title: Re: Gecko 320 , Servo
Post by: HimyKabibble on March 03, 2013, 11:41:21 AM
Current limit should  be set based on the motor specs.  If you set it too high above the motors rated current, a stall can permanently damage the motor, by de-magnetizing it.

Best way to set gain and damping is to start with both at a low-ish level (Gecko recommends starting at 10 or 11 o'clock position - about 30% of full scale, then gradually increasing gain to make the servo "stiffer", and adjusting damping to eliminating ringing and overshoot, while maintaining "crisp" response.  Keep in mind, none of these settings have much effect on accuracy, unless really massively mis-adjusted.  What they do is make the servo respond more quickly, allowing you to achieve higher rapid speeds, with higher accelerations.  With G320s, it seems best to adjusting damping so the servo "chirps" about once per second when the motor is not moving.  For G320X, adjust so it is silent, with perhaps a soft chirp every few seconds.

Regards,
Ray L.
Title: Re: Gecko 320 , Servo
Post by: Robhi on March 03, 2013, 02:29:23 PM
thanks too much, I guess that I understood a little bit.

Will try and let you know, hoping that I would not make a fire. lol
Thanks for all you

Title: Re: Gecko 320 , Servo
Post by: titchener on March 04, 2013, 11:54:17 AM
> Will try and let you know, hoping that I would not make a fire.

That was funny.