Actions
Forum Thread Details
  • State Not Answered
  • Replies 44 replies
  • Subscribers 33 subscribers
  • Views 5656 views
  • Users 0 members are here
Related

Stepper Motor Troubleshooting

fuzion_reaktor

Hello, my name is Peter R and for the past several months I have been building a 3D printer. I have the frame and everything done, but I consistently run into the issue where my stepper motors run erratically; when I issue a movement command they change direction at random, move in unpredictable spurts, clank, grind and make weird noises--and that's if I'm lucky enough to get them running at all. They appear to be uni-polar motors, and I have wired their four wires in as many orientations as possible and still get the same issue? Is this a board problem, or the motors themselves?

The motors are 17H249-02S motors, manufactured by Xuquan motor, but there is little documentation on them on the internet as far I have found.

Many thank to whoever can answer this.

Parents
  • 0

    'Chopper drive' means a current-source drive that is swichmode.  The CS driver is intended to minimize the effect of coil inductance.  Your motor coil has resistance and inductive reactance.  The coil is ill-wont to allow changes in the current going through it.  It sources its own potential to oppose attempts to change this current.  Current source drive introduces a super voltage during the initial moment to overcome (establish the new magnetic field) the reactive component of the load more quickly.  CS drivers are less sensitive to loading vagaries.

     

    Stepper motors at rest detent at the full steps.  If the rotor is intended to remain at rest in a micro-step, the ratio of the currents in the coils have to be maintained, but they can be mutually diminished.  This is the other side of chopper drive.

     

    It is sorta fun to adjust the current from an insufficient to a tenable range.  The motor clicks helplessly then get's it together, it's rather like watching a toddler rise from the floor.

     

    There was an interesting developmental pathway to these apotheosis off-the-shelf CS-chopper drives, which will soon, properly be lost to history.  In the early days, an external resistor was associated with each coil and the potential souped-up.  A common setup with industrial-grade printers was a 12V driving a 5V stepping motor with resistors 7/5s as large as the motor coil resistances.  The next step (neglecting nxQ schemes) was activating (cascode) the loads, but it took awhile to develop a current source circuit that was both modulatable and fast.  I've drawn the circuit that broke the logjam in another post.  Kids today!  You don't know how good ya' got it!

     

    I should note that, even if you just drive your motors detent-to-detent 'micro-stepping' is really sweet because it takes lotsa unwanted high-derivative mechanical energy from the system as regards square-wave drive.  The motor runs quieter, everything is smoother, less whiny.

Reply
  • 0

    'Chopper drive' means a current-source drive that is swichmode.  The CS driver is intended to minimize the effect of coil inductance.  Your motor coil has resistance and inductive reactance.  The coil is ill-wont to allow changes in the current going through it.  It sources its own potential to oppose attempts to change this current.  Current source drive introduces a super voltage during the initial moment to overcome (establish the new magnetic field) the reactive component of the load more quickly.  CS drivers are less sensitive to loading vagaries.

     

    Stepper motors at rest detent at the full steps.  If the rotor is intended to remain at rest in a micro-step, the ratio of the currents in the coils have to be maintained, but they can be mutually diminished.  This is the other side of chopper drive.

     

    It is sorta fun to adjust the current from an insufficient to a tenable range.  The motor clicks helplessly then get's it together, it's rather like watching a toddler rise from the floor.

     

    There was an interesting developmental pathway to these apotheosis off-the-shelf CS-chopper drives, which will soon, properly be lost to history.  In the early days, an external resistor was associated with each coil and the potential souped-up.  A common setup with industrial-grade printers was a 12V driving a 5V stepping motor with resistors 7/5s as large as the motor coil resistances.  The next step (neglecting nxQ schemes) was activating (cascode) the loads, but it took awhile to develop a current source circuit that was both modulatable and fast.  I've drawn the circuit that broke the logjam in another post.  Kids today!  You don't know how good ya' got it!

     

    I should note that, even if you just drive your motors detent-to-detent 'micro-stepping' is really sweet because it takes lotsa unwanted high-derivative mechanical energy from the system as regards square-wave drive.  The motor runs quieter, everything is smoother, less whiny.

Children