RUG/Pennsylvania/State College/Universal Paste Extruder
Contents
Overview
This page is dedicated to providing detailed information on how to build and use a universal paste extruder. These types of extruders are becoming more and more popular as can be seen in the media timeline.
Types of Materials That Can Be Used
- Ceramics
- Dough
- Cake
- Chocolate
Related Projects and Results
Below are details about paste extrusion projects that have been completed by students using this extruder.
Name | Students | Link | Description |
---|---|---|---|
Components
Name | Quantity | Link | Files | Price |
---|---|---|---|---|
Gear and drive set (small gear, medium gear, large gear, idler block, syringe pressure block | 1 | http://www.thingiverse.com/thing:20733/ | Gear and Drive Set | n/a |
Plastic Body V2 Extruder | 1 | http://www.thingiverse.com/thing:20733/ | http://www.thingiverse.com/download:64989 | n/a |
NEMA17 motor | 1 | http://www.omc-stepperonline.com/nema-17-unipolar-stepper-031a-158ncm224ozin-17hs130316s-p-65.html | n/a | $10.76 |
T5 10teeth Metal drive Gear | 1 | http://www.thingiverse.com/thing:20733/#files | http://www.thingiverse.com/download:65633 | n/a |
624 Bearings | 4 | |||
608 bearing | 1 | |||
20mm M8 Smooth rod | 1 | |||
55mm M4 Bolt | 1 | http://www.homedepot.com/p/Unbranded-M4-0-7-x-55-mm-Stainless-Pan-Head-Phillips-Metric-Machine-Screw-2-Pack-12468/203540123 | $1.76/2 pack | |
75mm M4 bar or bolt | 1 | |||
M4 Hex spacer (or M4 wingnut) | 1 | |||
M4 plain nuts | 2 | |||
M4 Nylock nuts | 4 | |||
M3 Nuts | 6 | |||
20mm M4 bolts | 2 | |||
10mm M3 bolts | 5 | |||
M3 washers | 14 | |||
45mm M3 bolts for Idler | 2 | |||
springs or Silicon pressure spacers for Idler | 2 | |||
small zip tie | 1 | |||
5-6mm wide T5 belt ~about 40cm | 1 | |||
Plastic sheet | 1 |
Assembling
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).