Z Problems

Hello, I build my lowrider cnc a few moths ago and am just getting around to using it, and i am running into a problem. My X & Y axis move the correct amount but when i tell the Z axis to move up or down 10mm it only goes up or down by 3. so whenever i try and cut anything with depth the cut always comes out wrong. for example i tried to cut a push stick for my table saw out of 1/2 mdf but when the cut finished the end mill did not go all the way though and it only ended up going around 4mm down. And yes i checked my model and tool paths from fusion 360 and it should have cut all the way though the mdf. I did some research on this problem and came across lots of articles saying the steps / mm where not set correctly. so my question is how do i figure out the right steps / mm for my cnc?

my stepper motors are using the 32 step setting, and the cnc uses a T8 2mm pitch & 2mm lead threaded rod.

The Z axis assumes a 2mm pitch/8mm lead, so…

You can adjust the steps/mm with the LCD.

200 steps/rotation (Most common for these motors) * 32X microstepping is 6400 microsteps/revolution.

With a 2mm lead (mm/rotation)

If we divide these we get 6400 microsteps/revolution / 2mm/revolution = 3200 microsteps/mm.

If I had to guess, I’d say that you are probably set up for 800 steps/mm with a RAMPS firmware now.

With a 2mm lead on the screw, I’d probably adjust for 16X microstepping, but if you just change the jumpers to 8X, you’ll probably find that everything works fine.


Thank you. i set my steps / mm to 3200 like you said and it is now moving the correct distance.