MK3s clone crash in Y-axxis

Hi,

I bought a Prusa MK3S clone from China.

The calibration works fine, but when a printout is executed it crashes in the y direction.
The belt tension display is also incorrect.
My only conclusion must be that the clone uses the "Blurolls" stepper motors which has a need for a higher current setting.
I tried to recompile the firmware with a higher current setting, but then the calibration fails by saying that the y-axis path is incorrect.

Does anyone have a solution to these problems?
Does anyone have a working "Configuration_prusa.h" file for the MK3S with the correct changes?

The way I see it, I have only three options.
1. The firmware is changed to compensate for the higher currents used by the "Blurolls".
2. Switch to LDO stepper motors.
3. Run the 3D printer only in "stealth mode".

Best Regards
Johan

You can't just use a general config for a machine without knowing which model you have. The MK3S clones are not all the same so if you want to have good advice let us know what machine you got exactly.

What do you exactly mean by 'crashes'? Does it keep on moving beyond the bed? Does it lose steps? Please be more clear

What is the exact error message, I haven't seen an 'y-path axis is incorrect' message before. What did you change, only the stepper current or?

What stepper drivers does the machine use and of course, belt tension can be tuned so that's a bit of mechanical adjustment.

---

http://www.marinusdebeer.nl/

Hi thank you for your reply.

I have a Triangle lab MK3S clone with Blurolls stepper motors.

Running the calibration wizard with the Prusa original firmware works fine, but when starting the print it crashes in Y axxis when it starts to lay the boarder.

Reading out the belt tension after self check show low numbers which means high belt tension.
These values do not change after changing the belt tension.

I can also se a small jump on the y axxis during callibration when the carrige passes midpoint .
I have checked the bearings and eveything seams ok there. The carrige run just as smoth as on my original prusa MK3S.

Then I read in to some treads that the Blurolls stepper motors needs a higher current and I came to the conclusion that this must be it.
So I downloaded the source code from Prusas Github, canged the currents some mA and recompiled the SW.

Flashing the firmware and started to recalibrate the machine, but then the carrige stops half way of the travel length after finding end point and calibration wizard says that the travel length is faulty in y.

Best Regards
Johan

Edited 6 time(s). Last edit at 01/09/2020 08:30AM by jsvens.

Tried to recompile the firmware once again now with the new current settings:

#define TMC2130_CURRENTS_H {18, 22, 35, 30} // default holding currents for all axes (16, 20 original values)
#define TMC2130_CURRENTS_R {18, 22, 35, 30} // default running currents for all axes (16, 20 original values)
#define TMC2130_CURRENTS_R_HOME {8, 10, 20, 18} // homing running currents for all axes

Now when doing a belt tension test the values got even worse than before.
X: 125
Y: 92

Belt values with Prusa original firmware:
X: 147
Y: 113
Carrige still make a small jump in Y

Could this indicate that currents are to high?

So I lowered the currents and now the belt tension values went up:
X:145
Y:112

and it still crashes in Y during print...

Best regards
Johan

I lowered the currents even more and now suddenly I do not get the Crash in Y and it finally Prints the whole boarder.

I can also see the belt values closing in on the 200 range.

I did some mechanical adjustment to the belt tensions but the values are still under 200.

So how low is reasonable to set the currents and does this mean that these stepper motors are more powerful than the LDO’s?

Best regards
Johan

Edited 1 time(s). Last edit at 01/10/2020 02:28AM by jsvens.

hello. i have exactly the same problem.
belt status is completely off and i had to turn off the crash detection.
bearing are the worst i had seem so far. the gt2 idlers also the same.
for the positive side the mk52 is great. psu. extruder. lcd. einsy. etc...

did you figure out the correct current, voltage, impedance, resistance?

tks a lot in advance

The X/Y/E: impedance 6.4ohm,current:1.2AThe X/Y/E: impedance 6.4ohm,current:1.2A. Newton force0.45nm. Z motor:mpedance 7.2ohm,current:1.2A. Newton force0.45nm.. Newton force0.45nm. Z motor:mpedance 7.2ohm,current:1.2A. Newton force0.45nm.