Possible Error in Microstepping

Hi guys. I am currently faced with this problem of my Lulzbot TAZ 3 printing only half of the desired part height. A friend told me it might have something to do with the compatibility between the layer heights issued for the STL file and the one read by the machine. I checked, and they were the same. I tried reducing the layer thickness by half to ensure compatibility, and it bore the same half-height results.

Eventually, I measured the Z-axis displacement, and found out for every 10mm input, the extruder moved only 5mm. I wonder if it has something to do with the microstepping of the motor. I am using Printrun, I couldn’t find out why.

Please help. :cry: It has been affecting all my prints for a while now.

What firmware version is installed?
When you turn the printer on, the LCD will display the printer model and version.
If you installed TAZ 4 firmware, the Z height will be off as you described because the Z lead screws on the 4/5 have a different pitch than the 3.

Thanks for the reply. The firmware is indeed TAZ 4. How do I solve the problem then?

Here’s how to flash firmware from Cura: https://www.lulzbot.com/learn/tutorials/firmware-flashing-through-cura
Assuming you have the stock Budaschnozzle hotend, and haven’t upgraded to the V2 hexagon, this is the firmware to use: https://devel.lulzbot.com/TAZ/3.1/software/2014Q2/firmware/marlin/Marlin_taz3.1.cpp.hex

Thanks again.

The initial values I got for the all steps/mm are:
X- +100.50
Y- +100.50
Z- +1600.0
E- +850.0

I increased the Z-step/mm to 3200, and got the Z-displacement right at last. But this implied too hight a speed for the motor whenever I tried homing, as it caused the thread of one of the rods to slip every now and then, resulting in uneven Z-displacement on both rods.

May I know how to set the stepping speed?

That is the wrong Z step rate for a TAZ 3. The firmware update Z step rate for the TAZ 3 Z rod thread pitch should have been correct after the update and not needed changed.

There is at least one copy of the stock taz 4 firmware labeled as taz 3 running around the site somewhere. It shows up from time to time, but I’ve never gone looking for it.