Apologies for not know the exact terminology for this.
I"m new to Lulzbot and just purchased a TAZ 5. I’ve been a cubex duo user for a couple of years and while through hacking and using KISSlicer was able to achieve good prints. It could never be used beyond that boundary.
I’m loving this printer and have used simplify3D and cura. The one problem i seem to have is that when beginning a print, the extruder never does a pre-extrude and thus every time it starts printing, nothing comes out for the first 2-3 seconds. On my cubex, before printing it would go the very back of the printer and let a few seconds of filament come out into a bin, then move over and start printing. Am I missing something in the programs i’m using, or is this just something that Lulzbot doesn’t do?
You can increase the amount of skirt that is printed around a object in one of the advanced settings, which will give it more of a chance to get things primed. I’m tending to manually extrude 10mm before I hit the print button, just to make sure I’ve got things primed. Generally, I only need to do this if I haven’t printed anything in a while (so filament has oozed out), or sometimes if I’ve cancelled at the wrong time in part of the previous print (on the Mini, the filament is retracted 30mm prior to going through a wipe sequence to clean the nozzle. If I cancel before it starts printing - for example if I don’t like what I see in the Mini’s auto-level sequence, I’ve got to manually extrude 30 mm to get it ready to print again.)
I was also not satisfied with the default priming process. I’m extruding an “anchor” in my start scripts now, followed by a single skirt for priming the nozzle. This works great for me. Here is my start code:
G28 ; home all axes
G21 ; set mm units
G90 ; set absolute coordinates
G92 E0 ; reset extrusion distance G1 E5 F1800 ; extrude anchor
G1 Z5.0 F300 ; move platform down 5mm
G1 Y20 F3000 ; move away from the anchor
No, it extrudes 5mm of filament at home position. Then the nozzle moves up 5mm, then 20mm to the back and start printing. The extruded material sticks to the bed, the nozzle is sort of cleaned during the process.
So the nozzle is at print height and extrudes 5mm while stationary? I may try something like this on my Mini, after the auto-leveing process has completed. I was wondering if it leaves a bird’s nest of filament stuck to the nozzle, or if most of it gets left behind. Sounds as though this is worth trying out.
Thanks so much for the reply Sebastian. I will try this.
I’m assuming that there is/was some sort of priming since the X axis goes a few inches past the bed on the right side. I figured that was used for a priming dump or something.
This works on my Taz 5 with inductive probe. Only use this code if you have the inductive probe added.
G91 ; switch to relative positioning
G1 Z10 ; safe raise of z axis to ensure probe doesn't hit bed clamp
G90 ; switch back to absolute positioning
G28 ; home all axes
G29 ; level print bed
G1 X298 Y137 Z2 F5000 ; move to wait position right hand side of the table
G1 Z0.4 ; position nozzle
G1 E25 F300 ; purge nozzle
M400 ; wait for purge to complete
G1 X285 F1200 ; slow wipe
G1 Z0.5 F1200 ; lift
If you don’t have auto leveling you can add this code to the end of your current start gcode and it should work.
G1 X298 Y137 Z2 F5000 ; move to wait position right hand side of the table
G1 Z0.4 ; position nozzle
G1 E25 F300 ; purge nozzle
M400 ; wait for purge to complete
G1 X285 F1200 ; slow wipe
G1 Z0.5 F1200 ; lift
wouldn’t an easier way be retract at the end of every print and then extrude that much at the start of every print? Then nothing would be wasted (and no skirting needed).