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Z axis jerky only driver gets very hot X Y are ok

lionellvplionellvp
in Motor Control
Hello,

I have problems with the correct control of the motors of the Z axis, the engine does not rotate or only minimally and the driver gets very hot. Same use of the same configuration with the X axis and the Y axis show no problems. The subject search for similar description showed me nothing useful.

My data:
- MKS Gen 1.4 DRV8825
- Repetier Firmware 1.0.3

What I have tried so far:
- bought used motherboard with Marlin firmware - works
- Motors changed
- Driver changed
- Steps changed per millimeter
- Acceleration of the Z axis reduced

Comments

  • lionellvplionellvp
    Of course you could also say, just take the Marlin board and good, because I use a Repetier Pro server I would like to stay with Repetier.
  • RepetierRepetier
    DRV8825 drivers are slow. I think you need to set STEPPER_HIGH_DELAY 1 so they see all signals. Especially if you have high steps per mm it might go into double/quad step mode where stepper timings become more important.

    Z axis are always enabled normally to hold position. So temperature depends on driver and current defined. Should have a cooler and best is a fan on driver also for other drivers to keep them cool.

    If it sounds like loosing steps try jerk 0.1 and acceleration 50. Especially z can not accelerate or start with high speeds without loosing steps, so this is also essential.
  • lionellvplionellvp
    Thanks for the help, in the end I changed the engines again. In addition, I have determined with the gauge and dial gauge the correct steps per millimeter.

    How can you actually prevent the slide from moving 3cm to the right again after the X limit switch is triggered?
  • lionellvplionellvp
    X OFFSET Dual Extruder was the answer
  • RepetierRepetier
    The 3cm is because you have selected left extruder. Then it will move distance to right extruder so you can select right extruder at same spot. Distance is defined by x offset. Setting it to 0 is wrong - then when you switch extruders the right extruder will print at the wrong space. This offset is intentional! Having multiple extruders reduces printable x area by the offset to left and right. Printable is only where both extruders can extrude!
  • lionellvplionellvp
    Repetier said:
    The 3cm is because you have selected left extruder. Then it will move distance to right extruder so you can select right extruder at same spot. Distance is defined by x offset. Setting it to 0 is wrong - then when you switch extruders the right extruder will print at the wrong space. This offset is intentional! Having multiple extruders reduces printable x area by the offset to left and right. Printable is only where both extruders can extrude!
    The printer is designed so that the right extruder has a left 35mm offset but the right one can print from the edge of the print bed. As to the entire print bed is a non-printable area of about 30mm. Would then OFFSET E0 = 0mm and E1 = 35mm the correct configuration or can one provide the E0 also with -30mm?
  • RepetierRepetier
    Normally you set left ones offset to 0 and put all offsets relative to that extruder.

    As I said also extruder 1 can print on the left side extruder 2 can not and switching extruder in that region would crash it into the end stop. So firmware does not allow that area after homing, also you can still move to it after sending G1 S0 to disable region check. But homing will still continue to be save.
  • lionellvplionellvp
    Everything is going pretty well now, thanks for the support. Finally, I have to say, if one manages to identify the problems individually, then the solution is not difficult. Topic can be closed.
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