Help with fine tuning Prusa Mendel

Its built and operational.
It extrudes both ABS and PLA plastic but ABS doesn't print well. Doesn't stick to build surface.
PLA does stick well but the build is too tall ie the z-axis moves too far with each layer.

I can't find a way of adjusting this feature within repsnapper so I assume that its done through firmware adjustments.
I'm just not smart enough with arduino to alter the z-axis movement.

Help needed.

Yes it's the z steps per mm value in the firmware.

Problem is, it's got different names in different firmwares. Which firmware are you running, on which electronics?

PS: It's just a matter of changing the values, and then recompiling and re-uploading the firmware.

PPS: The value for Z steps per mm (and x and y as well) can be calculated. Prusa himself put an online calculator on the net that allows you to work out the proper values (for Prusa or any machine), but the link is dead (404) at the moment. I've passed on to him that it's broken, so hopefully it'll be back online soon.

Running on gen 6 electronics, FiveD_GCode_Interpreter from mendel-parts.

ran his test piece well at least part of it and the piece was exactly 10 x 10cm so x,y seem ok but the z-axis for some part of it was too wide.

Thanks for your help

Rick

HI..

If you are using a prusa your Z axis in the firmware should be set to about 2650 whuch should give you 1mm of movement when you push +1.

If SF40 you need to tick limit and make both 1.0, this mean that if the part is 100mm high it should print to 10mm.

Auzze