Hi,
I made a CNC machine using a cnc shield v3 and A4988 drivers. And it was working fine but after removing and refixing the drivers. Nema 17 motors are now dosent hold any torque when moving so it can be stopped with fingers.
Power supply is 24v 2A.
Please advise me what went wrong
Those toy stepper drivers died.
Thanks for your comments.
But, i had a spare A4988 so i plugged it to check wheter its with drivers, but same happened.
Is it possible to die all 4 units and spare one without any significant change and at the same time.
yes, all can die at the same time. e.g. static discharge. but you could get your multimeter and do some mesurements. maybe your powersupply died.
Be VERY CAREFUL never to connect or disconnect the wires between the motor and the stepper driver while the driver is powered up. The driver will be instantly destroyed.
Thanks for your comments
My case is motors are moving but it can be hold by fingers even. Is it also a driver issue
sudesh_skt:
Thanks for your comments
My case is motors are moving but it can be hold by fingers even. Is it also a driver issue
Have you correctly set the current limit on the A4988 to match your motors. If the current limit is too low the torque will be low. If it is too high the motors will overheat and may be damaged.
Please post a link to the datasheet for your motors.
...R
Sure its connected correctly and securely?
I checked all the system couple of times and set the current limits and all settings which are not deffered from the previous perfect working condition.
I cannot imagine what is the wrong.
Now my motors are running as required, but will stall with tiny loads even with fingers motors are stalling.
Is that a,
- Driver failure
2.Software failure-already reset settings - Motor failure-all 4 motors are behave in same pattern
- Power supply failure-checked with a another unit behave the same way
- Normal condition-previously worked perfetly
Software has no effect on the motor dynamics, that's purely the motor driver current setting.
Steppers don't fail, they have one moving part.
Are you talking about torque at low speed or at high speed? Stepper torque drops very substantially
with speed (much more than any other kind of motor), and there's also the issue of resonance - without
microstepping or mechanical damping they are very prone to stalling/miss-stepping through resonance.
Perhaps you changed the microstepping settings?
From my own standpoint I would like to have more current available as 2 amps might be borderline.
Use at least 10 amps here and have a hard time stopping mine at either 12 volts or 24 volts.
It is also worth double checking / calibtrating the stepper current potentiometer too as they are often not the most robust and if tweaked too much can become useless.
ballscrewbob:
From my own standpoint I would like to have more current available as 2 amps might be borderline.
24v at 2amps is 48W. If the OP's motors need (say) 6 watts apiece then 48W should be plenty.
...R
Robin2:
24v at 2amps is 48W. If the OP's motors need (say) 6 watts apiece then 48W should be plenty....R
Just my own take Robin.
Belt and braces approach to things here.