Z axis moves 4 times to high

I just assembled my new Lowrider with SKR 1.3, Dual Endstops and a nice LCD. I followed the instructions of Saberlod, my german Lowrider2 guru

Anyway I’m not a programmer and have a issue with that I dont trust my Lowrider yet:

When I controll the Z-Axis and want to move it 10mm up it will move 40mm up.

I think the soulution i quite simple when I know where to look.
Can someone help pls??

Two reasons come to mind. First is that you don’t have the micro-stepping in the stepper driver set correctly. If you started from the V1 maintain firmware and are using either TMC2209 or the DRV8825 drivers, then your micro-stepping should be setup correctly. If you are using some other driver, then you should verify that micro-stepping is set correctly. Depending on the driver, it should be set to either 16 micro-steps, or 32 micro-steps.

If the micro-stepping is okay, the next thing is to check how the steps per mm is setup. Using a connected computer, or if you have a TFT display in the console, enter:


this will give your steps per mm for each driver. If your driver has 16 micro-steps, then you should get the values (100,100,400,100). If your driver has 32 micro-steps, you should get double that value:

Steps per mm can be changed in two ways. It can be done in g-code:

M92 Z400

The M500 save the result to the EEPROM.

Second, If you never used an M92, then you can edit the values and reflash the firmware. In configuration.h, see this line:

#define DEFAULT_AXIS_STEPS_PER_UNIT { 200, 200, 800, 200 }

if you already send an M92 to set the steps per mm, then changing the firmware will not change the values unless you do a M502 (factory reset) first.

Your Z steps is to high. Whatever it is currently set at set at, divide that by 4.

I would like to make it clear that your steps/mm are too high for your leadscrew. If your using the v1 firmware and supported drivers it’s probably off because you didn’t get the proper leadscrew. The solution is the same as stated above. Or if your not comfterble with that you could replace your leadscrew with the correct one.

I know they make a leadscrew 4x finer than the one V1 uses/recommends, but do they make a leadscrew that is 4x courser? Usually when steps are off by 4x it is the lead screw, but usually Z only moves 1/4 of the distance rather than 4x the distance.

Maybe I got it backwards? I thought a 1 start leadscrew was 4 times courser then a 4 start.

My guess is the guru gave them the firmware, and the guru is using a 1 start leadscrew.


Uhhh yes Robert,

I was looking for this solution. :slight_smile:
it was #define DEFAULT_AXIS_STEPS_PER_UNIT { 100,100,1600,100 }

now Z Asis is 400 now.

thx for the really fast help!!

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The Value 1600 is for T8x2 leadscrew, the Value 400 for the T8x8 leadscrew. u must set the accleration to the right value if you change the Z Steps.
if not u have a slower move on Z.