TAZ 4

Sudoroom has a TAZ 4 3d printer, that was donated in 2022. It should not be confused with the older TAZ 3 3d printer, which didn't work very well as a 3D printer.

Documentation for the TAZ 4 from Lulzbot corporation

The following start code should be entered until we can recompile the firmware M907 E150

The extruder head from the TAZ 3 was transferred onto the TAZ 4 which will presumably make a better 3D printer. The TAZ 3 will be converted for solder paste dispensing only

The TAZ 4 uses an Ultimachine Rambo 1.3L main board and here is the correct File:RAMBo 1.3L Schematic.pdf The original 14-pin "Extruder 0" connector on the TAZ4 was removed from "Aux Power Mosfet Output" (pins 5/red,6/black), E0 Heat (pins 12,13), E0 Fan (9/black,10/red) and Ground (pin 2), and E0 (3,7,11,14). The extruder harness from the TAZ3 was installed in it.

The TAZ 4 didn't work because both Fuse F2 and F3 on the RAMBO main board were missing. They're supposed to be Littelfuse OMNI-BLOK 154 series and we didn't have any, so I stuck 5-amp F1460CT-ND in there since we have dozens of them in the FUSES bin:

And now it turns on and mostly works, but the extruder stepper is mostly skipping. Most likely the current needs to be adjusted for the extruder stepper driver, which is something we have to read the manuals to figure out how to do - there are no tiny potentiometers to adjust on this RAMBO board, only a "digipot".

The digipots are controlled with the M907 command

the default values are found in Configuration_adv.h:#define DIGIPOT_MOTOR_CURRENT {175,175,240,135,135} // Values 0-255 (RAMBO 135 = ~0.75A, 185 = ~1A)

pins.h:#define DIGIPOT_CHANNELS {4,5,3,0,1} // X Y Z E0 E1 digipot channels to stepper driver mapping