SV06 Bulldozer: auto print ejection

SV06 Bulldozer:

What is it?

This toolhead attachment is designed for automatic print ejection for a print farm setting/ looping gcode. 

You can use this bulldozer to knock finished prints off of the build plate and start a new print, like in this video: Automatic 3D Print Removal using G-Code (youtube.com)

How to install:

This attaches onto the extruder body with 2 M3*8 screws. You would need to remove the original part cooling fan and fan bracket. It is compatible with cooling ducts that attaches to the back of the toolhead like this one: SV06 5015 Fan Duct Rounded by NAM1025 | Download free STL model | Printables.com

Note: The lowest point of the bulldozer is 5mm higher than the tip of the nozzle. You cannot eject anything lower than 5mm tall. The minimum recommended height for auto ejection is 15mm, and the surface area that sticks to the bed has to be fairly small compared to the height.

Automatic print removal:

You can either do this using gcode (linked video) or using custom software. I will make a tutorial about this soon.

You will need a print surface that releases the part when cool. The stock PEI bed is fine. 

Tips and tricks:

• when writing the end Gcode for print ejection, make sure to wait for the bed to cool down to somewhere below 30 Celsius (M140&M190) before it tries to knock off the print.
• You can write a “universal” end Gcode that sweeps the bulldozer over the entire width of the bed. This way you can print different objects in one run.

Offset Dimensions:

These are the offsets from the nozzle in case you want to program precise end Gcode to push the highest point of the print for easy removal.

z-offset: +5.0mm

x-offset (left side): 40mm

x-offset (right side): 45mm

y-offset: 65mm

Print settings:

• You can print in any filament. I used Carbon fiber PETG for the surface finish.
• print with decent amount of wall and infill: it should be fairly stiff. I used 20% rectilinear infill and 1.2mm walls.
• You can customize the front plate with text. It's super easy with the “text” tool in Prusaslicer & its derivatives.

IMPORTANT:

• remove the start gcode for purge line: this cannot be ejected and will cause the print over existing purge lines in successive prints.
• Don't use skirts!! like the purge line, skirts are too thin to be ejected. Use a thin Brim instead.
• Know what you're doing! This modification may cause damage to your printer and/or emotional damage, proceed at your own risk!