I have been searching around the internet for the last 3 days trying to figure this out, also posted in another forum but haven’t had any possible solutions yet :(. My Z axis motors for a pursa-i3 3d printer are not working correctly. I have marlin firmware and using repetier host. I send a command to move the z axis and I can get it to move, however if I send the same command again the motors will sometimes spin the other way. It feels like They almost randomly choose which direction they turn.
As I said I have been trouble shooting this for a while now. What I am suspecting is the firmware feedrates and acceleration or some setting in the firmware is not correct?
Here is my code:
//// MOVEMENT SETTINGS
#define NUM_AXIS 4 // The axis order in all axis related arrays is X, Y, Z, E
#define HOMING_FEEDRATE {50*60, 50*60, 2*60, 0} // set the homing speeds (mm/min)
#define DEFAULT_AXIS_STEPS_PER_UNIT {80,80,4000,590}
#define DEFAULT_MAX_FEEDRATE {300, 300, 3, 45} // (mm/sec)
#define DEFAULT_MAX_ACCELERATION {1000,1000,50,500} // X, Y, Z, E maximum start speed for accelerated moves. E default values are good for Skeinforge 40+, for older versions raise them a lot.
#define DEFAULT_ACCELERATION 1000 // X, Y, Z and E max acceleration in mm/s^2 for printing moves
#define DEFAULT_RETRACT_ACCELERATION 1000 // X, Y, Z and E max acceleration in mm/s^2 for retracts
#define DEFAULT_XYJERK 10 // (mm/sec)
#define DEFAULT_ZJERK 0.3 // (mm/sec)
#define DEFAULT_EJERK 5.0 // (mm/sec)
I tried swapping the drivers around and the motors will work perfectly on another axis so I don’t suspect it to be a driver issue. I have been turning the pots ontop of the drivers to make them work but can’t make motors to go the same direction I want them to.
I’ve checked the wires and I almost sure they are wired up correctly. (could be wrong but have checked it over with a multimeter.)
I am new to this and it’s my first time building one of these would appreciate any help I can get and and maybe I have over looked something I have tested. Just really want the axis to move in the direction That I say it to move in.
More details about my setup is: A Robocraze 3D Printer Controller Board RAMPS 1.4 using A4988 stepper motors drivers and my motors are the nema 17 stepper motors. I currently have the two z axis motors wired in parallel but have tried before using series, however the problem of being unable to control the direction of the Z motors still arises (can easily switch back to series).
currently trying with no load just to get the motors turn in the correct direction when I send a G-code command. I am using Repetier host on ubuntu 14.04.5.
I have also check the endstops and they are working perfectly, so they ain’t a problem (I don’t think :p)
Thank you, Bobby
