Clean or wipe move for delta 3D printers
I own a delta 3D printer. The problem is that, at the beginning of a print the extruder outputs dirty filament. I want a clean filament flow at the start of my prints!
How can I make the hotend exit the print surface (glass plate) by 10mm, extrude the bad filament and go back to printing again? Can this be done with G-code?
My Z high is 190 mm and the glass plate diameter is 120 mm. I'm using Marlin + Ramps 1.4.
I'm using Repetier-Host and CuraEngine as Slicer, but I really would like a G-code that can work on multiple environments like Cura and Repetier. I just want to add it to the start G-code and print!
You can achieve this using the
G1command. I don't know your exact printer, but you should be able to use something like this (add to the start G-code in your slicer):
G1 X0 Y62 Z0.2 F9000 ; Move slightly past edge of bed
G92 E0 ; Zero extruder position
G0 E1 F100 ; Extrude 1mm of filament
G92 E0 ; Zero again
G1 X0 Y0 F9000 ; Move back to center of bed
The first line moves the extruder to slightly past the edge of the bed (since the diameter is 120, the radius is 60, and 62 is slightly past the maximum radius). I've set Z to 0.2mm to avoid hitting the plate, but you might be able to lower this.
The next 3 lines zero the extruder position, extrudes 1mm of filament, and resets it to zero (when starting a print the slicer expects E to start at 0).
The final line moves back to the bed center. This might not be neccesary (you might be able to replace this line with just
G1 F9000to set the feedrate back to something that makes sense for travel moves) because you don't need to move back explicitly: the slicer will take care of moving the head in position to start the print.
This worked well for me : G1 X63 Y63 Z0.4 F9000 ; Move slightly past edge of bed G92 E0 ; Zero extruder position G0 E20 F100 ; Extrude 1mm of filament G92 E0 ; Zero again G1 X0 Y0 F9000 ; Move back to center of bed G28 ; Home extruder
I just added it to the end of the "start Gcode" Gcode and the nozzle purges at the start of my prints, pefect !
For those who are curious here is the finql result. https://www.dropbox.com/s/81odyromk5i09cw/IMG_20160821_230255.jpg?dl=0
I have found it preferable to hold the printhead well above the surface while oozing/pumping waste, as it makes it easier to grab than "barely above the plate surface (even if off the edge of it.)" But mostly I do that while heating up and oozing (hold it forward and 50mm off the deck) and then use a skirt to deal with getting filament to flow nicely before printing.