Summary

This part ejector is great if you want to automate your BIQU B1 to run 24/7! You will also need to:
-Use my Y axis belt cover to prevent parts getting caught in the belt: https://www.thingiverse.com/thing:4981059
-Use a bed clearing script at the end of your G-code (or for OctoPrint users, use the 'continuous print' plugin). Mine is listed at the end of this text.
-Change your start G code to prime off the edge of the bed to prevent build up of filament. Mine is listed at the end of this text.

This works well with this BL touch mount: https://www.thingiverse.com/thing:4564987

Bed Clearing Script:
M140 S0 ;turn off heated bed
G4 S1800 ;wait for 30 mins
M17 ;enable steppers
G90 ;back to absolute positioning
G28 X Y ;home XY
G1 X119 Y238 F6000 ;move to centre back
G1 Z1 F2000 ;move Z down
G1 Y40 F1000 ;eject
G1 Y238 F6000 ;return to back
G1 X79 F6000 ;move left -40
G1 Y40 F2000 ;eject
G1 Y238 F6000 ;return to back
G1 X159 F6000 ;move right +40
G1 Y40 F2000 ;eject
G1 Y238 F6000 ;return to back
G1 X39 F6000 ;move left -80
G1 Y40 F2000 ;eject
G1 Y238 F6000 ;return to back
G1 X199 F6000 ;move right +80
G1 Y40 F2000 ;eject
G1 Y238 F6000 ;return to back

Start G-code Script (THIS USES UBL LEVELLING!!! You may need to change it!):
; BIQU B1 Start G-code
M117 Heating Bed and Nozzle
M140 S{material_bed_temperature_layer_0} ; Set Heat Bed temperature
M104 S{material_standby_temperature} ; Set Nozzle temperature
M190 S{material_bed_temperature_layer_0} ; Wait for Heat Bed temperature
G92 E0 ; Reset Extruder
M117 Homing
G28 ; Home all axes

M117 3 Point Plane Probing
G29 A
G29 L1
G29 J

M117 Heating Nozzle
M104 S{material_print_temperature_layer_0} ; Set Extruder temperature
G1 Z2.0 F3000 ; Move Z Axis up little to prevent scratching of Heat Bed
G1 X0 Y0 F5000.0 ; Move to bottom left corner
G1 Z0.0 F5000.0 ; Move to Z0
M109 S{material_print_temperature_layer_0} ; Wait for Tool temperature
G92 E0 ; Reset Extruder

M117 Purging
G1 E30 F300 ; Purge off the side of the bed
G92 E0 ; Reset Extruder
;G1 E{-retraction_amount} F{retraction_speed} ; Retract by users settings
G1 X15 F300 ; Move onto bed to wipe nozzle
G1 Z0.2 F3000 ; Move Z Axis up little to prevent scratching of Heat Bed

M117 Beginning Print