RUG/Pennsylvania/State College/Universal Paste Extruder
Contents
Overview
Components
Syringe holder
Assembling
Mechanics
Pneumatics
Generating the gcode and printing
Slic3r (http://slic3r.org) can slice a CAD file into G-code for the paste extruder. It requires specific settings:
- Go to Preferences and turn Slic3r into expert mode
- Print settings:
- Layers and perimeters:
- Set the layer height to the right value (this value depends on the paste, and must be determined through experimentation)
- Set first layer height to 100%
- Speed:
- In the set for print moves sub-section, all the values should be identical, and equal to the printing speed determined through experimentation (it depends on the paste, the nozzle and the pressure)
- The speed for non-printing moves can be left to its default value
- Set the first layer speed to 100%
- Output options
- Download the perl script to turn extrusion commands into fan commands (Paste-perl.zip), and place it in any folder (don't forget to un-zip it). Then add its absolute path to the post-processing frame. On Unix, open the terminal and run the command "chmod 755 /path/to/the/script". Make sure that there aren't any white-spaces in the script's path (it may result in a crash). On Windows, you need to download and install a Perl interpreter: http://www.perl.org.
- Advanced:
- Set the first layer to 100%
- Layers and perimeters:
- Filament settings:
- Cooling:
- Disable both options (fan always on and auto cooling)
- Cooling:
- Printer settings:
- General:
- Set the G-code flavor to MakerWare (MakerBot)
- Extruder 1:
- Set the nozzle diameter to the right value (this value depends on the paste, and must be determined through experimentation)
- Set the retraction length to 2 (disabling it provokes a bug)
- General:
The post-processing script used turns the extruding commands into fan commands. If you plug the solenoid valve on the fan port, you won't need to re-flash the printer. Note that if you don't re-flash it, since there is a temperature security, you must left the regular extruder's thermocouple or thermistor plugged (considering that you took a working printer and replaced the extruder).
In order to determine the right values (this hasn't been done yet, and must be followed with caution):
- The layer height is close to the height of a printed paste line.
- The nozzle size shouldn't be set to the actual nozzle size, but rather to the printed paste line width.
- The speed depends on the nozzle size, the viscosity of the paste and the air pressure. Try to find values that result in a good print for these 4 parameters (including speed).