Stepper calibration way off/correct firmware?


I’m putting together an MP3DP, and I got all of the parts here. I’m using a Mini Rambo and a Titan Aero, so I flashed the MP3DP511_MRambo firmware found at the bottom of the MP3DP page. The only change that I have made to the firmware is in the thermal settings: #define TEMP_SENSOR_0 5 //MPCNC

The problem that I am having, is that for some reason when I try to move 10 mm, it moves almost 20 mm (in all directions). This happens with the LCD and Repetier Host. This is what I have in the movement settings: #define DEFAULT_AXIS_STEPS_PER_UNIT { 200, 200, 788, 200 } //MPCNC

Do I have the right firmware? Is there any other reason that I could be getting such odd results? It also seems like when I try to extrude some of the filament using the LCD/Repetier, it moves VERY slowly, compared to my experience with the ROBO 3D. I’m not sure if it is supposed to do that though, or if it could be at all related?



Change your steps to this, 100, 100, 400, 837.

I will have to look at the firmware you downloaded I have a few now so I will need to consolidate them.


voici la soulution de votre probleme sans modifier le firmware .

tu travail avec A4988 ou DRV8825.


Translate does not seem to be working well enough to help, Rissoual. The ramps firmware comes ready for drv8825. Any other board or driver will need adjustments.

voici le reglage des driver DRV8825 avec les cavalier .

Tableau des paramètres pour le pilote moteur DRV8825:

M0 M1 M2 Résolution du micro pas
0 0 0 Pas complet (valeur moteur)
1 0 0 1/2 pas
0 1 0 1/4 de pas
1 1 0 1/8 de pas
0 0 1 1/16 de pas
1 0 1 1/32 de pas
0 1 1 1/32 de pas
1 1 1 1/32 de pas

le bon parametrage est :

0 0 1 1/16 de pas

Rissoual, You need to start a new thread of your own.

Translate is not helping me to understand what you are asking.

I made the changes to my steps in the firmware to: #define DEFAULT_AXIS_STEPS_PER_UNIT { 100, 100, 400, 837 } //MPCNC

However, it made no difference. It is as if the original numbers are still in effect, and the actual distance travelled (in all directions) is still about double the distance that it should be. Any guess as to why that might be the case? The only place that I make changes is in the configuration.h file, correct?

Edit: I just checked on the LCD, and the original numbers are definitely still in there. I’ve updated my Arduino IDE, and I tried flashing from 2 different computers, but no luck. I can see lights on the Mini Rambo while it is uploading, and I can see on my computer that the uploading completes without any errors, but I can’t figure out why the numbers won’t change to the ones that I edit in the configuration.h file?



I can’t imagine it not throwing an error without actually flashing. Are you powering it while flashing (you should be)?


Which control card did you use ??


I second Ryan’s thought - you need to provide 12V as well as the USB connection to flash the mini-rambo.

Thanks to everyone that has offered suggestions! It turns out that I had accidentally clicked on “store memory” on the LCD. This kept the incorrect default axis settings, even after flashing the firmware again. I had to “restore failsafe” to revert to the firmware with the updated axis settings, and now everything seems to be working as it should.

Thanks again,


Wow good find, I will remember that for sure.

Félicitations et bon courage.

Moi j’ai une autre expérience avec le problème des pas. J’ai trouvé la solution de modifier les jumpers des driver, mais la carte de contrôle est (MKS GEN 1.4).