Setting up stepper motor drivers
Hi, i need some help/advice on setting up stepper drives, Currently trying to CNC my lathe i have a 14mm dia x 4mm pitch ballscrew for the leadscrew and a 8mm dia x 2mm pitch for the cross slide.
i have a Nema 23 on the leadscrew and a nema 17 on the cross-slide. these are driven MSD542's powered by a 50V DC 10A power supply.
I have setup the micro drivers to 8 microsteps, Is this possible too much? as the motors sound rough.
Some background ( i had the drives etc working on the old 8 TPI leadscrew) so there is no problemas with power motors or drivers..
Thanks
Roy
Re: Setting upstepper drives
Roy,
Have you tried any other settings ?
How are you connecting the motors to the screws ? Oldhams or lovejaw type couplings ?
Re: Setting upstepper drives
50V supply on 50V drive is bad idea.! . . . your in danger of back emf frying them on de-acceleration. On a lathe it probably won't be a massive issue because it wont be de-accelerating from high feeds but @50V your on the edge.!!
First I would double, triple check all your wiring, esp the motors phase connections.
Check your amps are not set too high on drive, then like john says try other settings.
What model motors are they.?
How have you got the motors wired.? Parallel or series or unipolar.
Re: Setting upstepper drives
I think it is just my settings. as the only thing that changed was to replace the myford leadscrew with a ballscrew.
coupled with a belt 20 tooth on the motor and 40 tooth on the screw.
Quote:
Originally Posted by
JAZZCNC
50V supply on 50V drive is bad idea.! . . . your in danger of back emf frying them on de-acceleration. On a lathe it probably won't be a massive issue because it wont be de-accelerating from high feeds but @50V your on the edge.!!
First I would double, triple check all your wiring, esp the motors phase connections.
Check your amps are not set too high on drive, then like john says try other settings.
What model motors are they.?
How have you got the motors wired.? Parallel or series or unipolar.
Re: Setting upstepper drives
Thanks John,
i been fiddling with the settings in MACH since the screw changed from 8TPI to 4mm pitch. so i am guessing this is the area of problem.
PS, assembling the PCB this afternoon to test. will keep you posted.
Quote:
Originally Posted by
John S
Roy,
Have you tried any other settings ?
How are you connecting the motors to the screws ? Oldhams or lovejaw type couplings ?
Re: Setting upstepper drives
Try different velocity and acceleration settings in Mach
Re: Setting upstepper drives
Quote:
Originally Posted by
croy
I think it is just my settings. as the only thing that changed was to replace the myford leadscrew with a ballscrew.
coupled with a belt 20 tooth on the motor and 40 tooth on the screw.
Please dont take this wrong way but you have changed the steps per to take into account the gearing.?
Re: Setting upstepper drives
Hi No i dont think i have.
Dont worry i am not offended just grateful for the help
Re: Setting upstepper drives
Quote:
Originally Posted by
croy
Hi No i dont think i have.
Dont worry i am not offended just grateful for the help
Well there's your problem then.
If 1600 micro steps and 4mm pitch with 20T on motor and 40T screw then try 800 in steps per. So formule (micro steps/pitch) * (screw pulley/motor pulley)
Re: Setting upstepper drives
Thanks, i am going to finish watching the rugby, then i'll give it another try.
Quote:
Originally Posted by
JAZZCNC
Well there's your problem then.
If 1600 micro steps and 4mm pitch with 20T on motor and 40T screw then try 800 in steps per. So formule (micro steps/pitch) * (screw pulley/motor pulley)