[calibration] Only Right Z axis stepper moves
Hi,
I have a problem with my Prusa MK2 kit version printer.
I assembled it few days ago and it worked. It passed selftest, calibration and it printed few things.
Today I realized that I have a problem with z-axis. Left stepper is losing steps (I think that it lose only microsteps - but I don't know how to check it). At the beginning it wasn’t so big problem – after each print I recalibrated z-axis and it was ok. But today the printer refused to pass calibration (on 2 from 4 points). During calibration mainly only right z axis stepper is moving. Left one don’t move most of the time. I think that is the reason why the printer refused pass calibration today.
Do you know how to fix it?
Re: [calibration] Only Right Z axis stepper moves
Sounds as though you have a damaged motor cable or bad connection at the RAMBo.
Check the plugs for both Z motors are firm and the pins are fully home in the connector.
If that's OK, then have a look at the cable for damage; see if it is pinched anywhere, particularly where the motor is held against the Z frame where the wires exit the motor.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: [calibration] Only Right Z axis stepper moves
Hi,
thanks for so fast reply,
I checked both steppers - all coils seams to be fine - every coil is something like 9.1 ohm. On left stepper cables no signs of any damage (only one cable strap is on it).
If I swap the z-axis plugs in rambo board - only left got problems...
Both z axis I can move by my fingers, so there is not much to move ...
Do you know how to check microsteps with Pronterface - I tried to play with M350 commands but I failed - axis move only on full step...
added:
all connections seems to be fine - axis move - but only on full step ...
Re: [calibration] Only Right Z axis stepper moves
Did you try high power mode?
Re: [calibration] Only Right Z axis stepper moves
Hi,
I use only high power mode...
small update:
after contact with [email protected] I played a little bit with P.I.N.D.A. probe height, and successfully my printer pass all calibration steps. But unfortunately, after full XYZ calibration it still need Z axis calibration
This is how printer looks after full XYZ calibration.
But this time during calibration I saw that left Z axis stepper did moved when the right one was not moving. So it looks like only one Z axis stepper can do microsteps at the same time...
Re: [calibration] Only Right Z axis stepper moves
Well if you switched the cables over and the problem moved to the other motor, there is a problem with either the connector or the RAMBo.
I think you need to contact support via Live Chat on shop page and give them a link to this thread.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: [calibration] Only Right Z axis stepper moves
Hi,
that was the first thing I thought - but it is not exactly like this. Simple switching Z axis connectors didn't change anything. During one calibration process only one stepper do the microsteps - at the beginning it is the right one, then it is the left one, but not both at the same time.
For me it seams like a current limiting problem - there is not enough current to drive both steppers at the same time - which lead to the problem with PSU or electronics - but as you said - I contacted [email protected] and I'm waiting for good news 😉
Re: [calibration] Only Right Z axis stepper moves
You can put more current into Z motors by gcode command. But I think they get enough power at the moment, the problem is most likely somewhere else.
Re: [calibration] Only Right Z axis stepper moves
You can put more current into Z motors by gcode command. But I think they get enough power at the moment, the problem is most likely somewhere else.
Absolutely; there are thousands of these printers out there and working without this problem...
Just one more thought: do you have the adjusters on the right (2 screws at the end of the X carriage) correctly adjusted? If not, they could put too much load on the Z motors. With the printer switched off, you should be able to hold the centre of the X carriage and pull it upwards without too much difficulty.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: [calibration] Only Right Z axis stepper moves
Did anyone else notice that the z-axis trapezoid nuts are installed wrong?
Re: [calibration] Only Right Z axis stepper moves
Did anyone else notice that the z-axis trapezoid nuts are installed wrong?
Nope. Really should have noticed that!. Well done! I suppose that also begs the question: what else is assembled incorrectly?
Answer: Cable management is wrong for a start. Look at the droopy extruder cable bundle.
BTW, regarding the filament drive pulleys and the shop... Apparently one has to be authorised to access that part of the web shop and I wasn't. So thanks for raising that as well!.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: [calibration] Only Right Z axis stepper moves
Did anyone else notice that the z-axis trapezoid nuts are installed wrong?
They are upside down, but that's not wrong. The printer will work well with that, as well as my own two printers do.
Re: [calibration] Only Right Z axis stepper moves
Hi,
thanks for all sugestions. The nuts are now correct.
I think I found the reason why my printer calibration fail.
It was not the issue with left Z axis stepper - the problem was with Z axis right stepper. Right Z screw cover was to tight...
Re: [calibration] Only Right Z axis stepper moves
They are upside down, but that's not wrong. The printer will work well with that, as well as my own two printers do.
Actually, according to the build manual installing them upside down is wrong. Whether or not they work that way is immaterial. As Peter said, if this part is installed wrong what else may be wrong on the build.
Looks like the problem has been resolved.
Happy Printing!