Taz Workhorse won't print first layer

Taz workhorse that I’ve had for 4 months now won’t always print first layer. I frequently have to adjust the z offset to get a first layer, then on the next print, it will sit too low on the bed and not put out any filament, but instead will wipe off (the glue stick) I’ve put on the bed. I’m guessing there is a problem with the leveling system. I’ve tried tightening up a few areas, leveling the X axis, etc. This problem pretty much makes Taz useless. I have a MINI 2 that works extraordinarily well. Taz is a huge disappointment.

Any ideas? is there an adjustment or an area I haven’t addressed?

It’s the auto leveling system. Doesn’t work because it relies on the nozzle-tip and the nozzle gets dirty. Nozzle is dirty because the auto wipe system doesn’t work. Auto wipe system doesn’t work because Taz nozzles are different? I’m not sure further than that. I have resorted to manually + thoroughly cleaning the tip on my Taz Pro every time I use it. It’s a PITA and timesink. Permanent solution is making the auto-level design rely on a separate always-clean metal-rod always (instead of risking dirty nozzle) or get the nozzle-cleaning always-working… but I’ve attempted #2 multiple times (different wipe materials, diff temps) and #1 is a timesink category of its own.

Btw, I’ve also had to add shims to the lower-left corner of the bed-spacer because the auto-leveling doesn’t even work properly even with a clean tip (!). I’m hoping it’s just because there are some physical deflections that auto-leveling cannot overcome (as opposed to a straight up auto-level SW problem).

I have hundreds of hours on the Mini 2 and Taz Pro and share your sentiment. The Mini 2 is excellent. Taz has been a solid PITA; thank goodness it at least prints.

Also I recommend you drop Lulzbot Cura and just use Ultimaker Cura with the start/end gcode copy pasted over as a custom printer. Night and day quality difference (no more memory leak crashes, no more waiting for undesirable auto-slice to finish, etc).

Sounds like my Mini 2. That auto-leveling has been a pain. It always has the back left corner higher then anything else when it prints.

I even sent it back to LulzBot and they said “oh the glass bed was warped” and shipped it back. I went and tested it, it’s still doing the same thing. Been doing it for the few months I have owned it. My Taz 6, running the same firmware doesn’t have this issue. It’s something to do with this new series.

Also that’s interesting what you say about Ultimaker. I have been getting tired of it crash when I try to larger slices (still haven’t been able to do my sister her Mando helmet) . Thought you know you can turn off a setting for the auto slicing right.

I got a Workhorse a little while ago. It was the first 3D printer I’ve owned that had auto-leveling, and something that I didn’t know is that if the bed deflects AT ALL when the nozzle touches down on the corner washers, then the levelling will be off. In my case it was always due to a dirty nozzle, despite the wipe-cycle.
I wait until the nozzle has heated for wiping, then quickly scrub the nozzle with maroon scotch-brite pads.
I’ve printed out the alternative wiper holder from this post: Improving Lulzbot FDM 3D Printers : 9 Steps (with Pictures) - Instructables, but I haven’t installed it yet.

I also spent a LOT of time trying to figure out why my print bed Z-height seemed fine on the left-hand side, but too far away on the right-hand side.
I eventually tracked my problem down to having different height bed supports (the squishy ones) on the left and right. Lulzbot sent me free replacements.

Along the way, I found comments saying that the bed-levelling won’t work if the min and max height of the levelling washers exceed a certain amount ( 0.5mm, maybe?).
This post helped me with printing out shims and adjusting things: SOLVED: Taz 6 auto leveling is >0.5mm off (NOW PERFECT TO 0.01mm!) - #5 by cmidgley

I’ve removed auto bed leveling from all of my print profiles and now exclusively perform a manual zeroing and bed leveling when I reset my printer. This resolves the problem of ooze, wipe and calibration temperatures being off for some filaments. I now successfully run through the calibration process 100% of the time. It also means that I can use more or less any silcer and not need to create hacky support for the per-fillament melt and wipe temperatures.

My process is:

When I start a printing session, I have no filament loaded from the previous session as ambient humidity here saturates it. This also means that I don’t have to worry about oozing during calibration.

Preheat bed and set nozzle to 150 C

Clean nozzle with small tool, paper towel and gray scotchbrite.

G28
G29

Start first print. The startup gcode does not contain zeroing, wipe or calibration instructions. Here is the gcode I use for precalibrated prints (template is in slic3r format. If you use this in cura, you’ll need to replace them with cura variables):

; This G-Code has been generated specifically for the LulzBot TAZ 6 with standard extruder
M73 P0 ; clear GLCD progress bar
M75 ; start GLCD timer
G26 ; clear potential 'probe fail' condition
M420 S1 ; activate bed level matrix
G90 ; absolute positioning
M425 Z ; use measured Z backlash for compensation
M425 Z F0 ; turn off measured Z backlash compensation. (if activated in the quality settings, this command will automatically be ignored)
G1 Z20 E0 X140 Y-15 F3000 ; position nozzle over front edge of bed for heating
G1 Z1 F3000;
M117 Heating... ; progress indicator message on LCD
M109 R{first_layer_temperature[0]} ; wait for extruder to reach printing temp
M190 R{bed_temperature[0]} ; wait for bed to reach printing temp
M82 ; set extruder to absolute mode
G92 E-5 ; set extruder position to -5
G1 Z2 E0 F75 ; prime tiny bit of filament into the nozzle
M400 ; wait for moves to finish
M117 TAZ 6 Printing... ; progress indicator message on LCD
; END_START_GCODE