Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: rodeoinamo on April 29, 2012, 06:59:47 AM

Title: stepped motor soft start
Post by: rodeoinamo on April 29, 2012, 06:59:47 AM
hi everyone.

i have a problem with ramping of stepped motor. it is noisy, it sounds like gear crash not too much but i feel the motor is forced. you know we want soft start for motors. how can we manage to get soft start with mach3?

thanks a lot
Title: Re: stepped motor soft start
Post by: ger21 on April 29, 2012, 07:03:01 AM
It sounds like you're getting resonance on your motors. Adding a damper can help to make it smoother.
Title: Re: stepped motor soft start
Post by: rodeoinamo on April 29, 2012, 07:33:48 AM
but my resonance problem is just for first start after a few seconds no resonance happens. i just want to fix first start resonance i tried velocity and accelaration tunings but was not succesful
Title: Re: stepped motor soft start
Post by: kf2qd on May 01, 2012, 06:28:42 PM
Stepper motors do make noise. You are hearing the the motor line up the magnetic poles. At low speeds you have max torque and the noise is louder than at higher speeds. The other reason for the noise can also be mechanical/structural. The machine structure is resonating and amplifying the sound of the motors. Its a fact of life with steppers. Stiffen up your motor mounts.
Title: Re: stepped motor soft start
Post by: Picengraver on May 01, 2012, 09:00:34 PM
Are you using microstepping or full step?
John Champlain
www.picengrave.com
Title: Re: stepped motor soft start
Post by: rodeoinamo on May 04, 2012, 04:45:23 PM
when i set step per to 40 it goes mach3 and my measurement device both show 1mm. it means 1/1 full step. what should i do?
Title: Re: stepped motor soft start
Post by: Picengraver on May 05, 2012, 06:19:19 PM
If you are running full step mode (200 steps = 1 full revolution of the stepper motor shaft), that may be your problem.  Your drives should be capable of microstepping - most are.  Try setting them to 1/2 or 1/4 microstep and adjust your 'steps per' in Mach3 to match.  The steppers should then run smoother and quieter.

Regards,
John Champlain
www.picengrave.com