I’ve just started experimenting in this field with incremental success. There exist some paid services out there that provide all the GCODE modification you need, but I’m cheap so I asked AI. There’s also some files that you can print which tilt the printer so that the print rolls in a semi-controlled fashion, and help with scraping it off the bed. Below is the GCODE I’ve been using:
; ========== COOL DOWN AND EJECT ==========
M104 S0 ; Set hotend temperature to 0°C
M140 S0 ; Set bed temperature to 0°C
G4 P1200000 ; Pause for 20 min (1,200,000 ms)
; Vibrate bed to loosen parts
M970.3 Q1 A7 K0 O2
M970 Q0 A10 B50 C90 H15 K0 M20 O3
; Scrape parts off the bed
G1 X25 Y185 F18000 ; Move to back-left
G1 Z0.2 F900 ; Lower nozzle near bed
G1 X25 Y-1 F500 ; Push parts forward
G1 X25 Y185 F18000 ; Return
G1 X75 Y185 F18000 ; Start next column
G1 X75 Y-1 F500 ; Push next column
G1 X75 Y185 F18000
G1 X125 Y185 F18000
G1 X125 Y-1 F500
G1 X125 Y185 F18000
G1 X175 Y185 F18000
G1 X175 Y-1 F500 ; Final push
;========== REPRINT GCODE HERE ==========
In order to use this, you tell Bambu Studio to export the .3mf to a folder you specify, then use your favorite un-zipper app to extract the contents. In the “Metadata” folder you’ll see a file of the type GCODE that’s named something like plate_1 (I haven’t tried this with multi-plate prints yet…). Open that GCODE file with a text editor, I use Notepad++ because of its handy features for searching and selecting.
I’ve been selecting the whole block of code from initialization (right after the little song it plays, thankfully the code is well-notated) all the way down to a line that reads “G1 X0 Y90 F18000 ; move to safe pos.” You’ll want to put that code snippet right after this line. Then I copy the GCODE I’ve selected into a new file named plate_1_justGCODE and paste that reprint code from above onto the end also. Basically, when it finishes printing you tell the printer to shut down the heaters and wait twenty minutes. Then it starts a push routine which “gently” slides the extruder into your prints and off the front of the machine. Put a spool box there and you’ve got a print farm!
Copy and paste this modified GCODE back into your original file at the appropriate spot as many times as you would like to reprint things, then importantly save the file in its original format. If you save it as a text file, the printer won’t be able to read it (ask me how I know lol). I also went and located the line that contains “; draw short stabilization pattern” and edited the Y coordinate in that block of code for each successive print, this moves the small purge line the printer makes before printing the file. Now you’ve got to go back to your un-zipper app (I’ve been using 7zip), open the archive and drop your new GCODE file in, replacing the original one.
Now you can either drag the .3mf file onto your SD card from within file explorer, or open the 3mf in Bambu Studio and upload it (I haven’t tried this second option yet, but I have opened the modified file and checked the print sequence bar on the side. The time estimates seem to be correct, and theoretically it should just upload like any other project file…)
Play around with how long it waits, I’ve only been using this on small parts so they tend to come off ok. As the build plate cools, you might hear a slight clicking or popping of the part starting to break free from the texture of the build plate. I suggest being present for your first go-around, just to make sure you’ve got the appropriate wait time set and that you’ve moved the purge line far enough away to not get stuck on the extruder nozzle. Have fun!
