This week neil gave us a bunch of questions about our final project to answer...
So let´s think about my paste-extruder
What will it do?
As the name says, the paste-extruder will extrude pastes ;)
Mainly it is planed for chocolate, but also marzipan, concrete or ceramics should work with it.
The extruder will be splitted into two parts: a reservoir and the extruder. Both parts will be heated
for making the chocolate pasteous. They will be connected by a short piece of silicon-hose.
All parts will be made out of food-safe materials and easy to clean.
The extruder-control will be stand-alone, so it is universal to any kind of XYZ-Machine.
The only signal used will be the step-signal for the forward feed.
Reservoir and extruder will be thermical-isolated by a mixture of gypsum and styropor.
This prevents burned fingers and will safe a lot of energy.
Who's done what beforehand?
You can find a lot of paste-extruder-projects on the web.
is for example a long list of these projects.
Most of them uses a syringe that is compressed by some kind of mechanic. I think that this
is very inaccurate, due to the compression in the material. The material-flow is not very even, and the flow
doesn´t stop immediately when the extruder-motor stops.
Because of this my extruder will use a syringe only as a reservoir, but for the extrusion itself a archimedes-screw.
I found only one project that goes into the same direction: 0x7d.com
Main differences to this project:
My syringe will not be driven by air pressure, but by some kind of e-motor (lack of compressed air ;))
My syringe will be heated
My archimedes-screw and the needle will be heated
All parts will be made out of food-safe material
What materials and components will be required?
The syringe for the reservoir will be a "Perfusor"-Syringe from bBraun:
The syringe will be compressed by a dc-motor with some kind of trapeziodal-screw
The extruder will be driven by a stepper-motor
All other parts will be milled out of aluminium
The electronic will regulate the temperature, the feed of the syringe and the feed of the extruder
Where will they come from?
DC- and Stepper-Motor: amazon or ebay
Heating: Kanthal-wire and Kapton-Tape
Trapeziodal-screw: left over from the Poor-Mans-Mill (MTM)
Archimedes-Screw: milled by hand out of aluminium
Electronics: selfmade, components from farnell, mouser, etc.
How much will it cost?
Hard to say, but i think about 100$ all in...
I will write a complete list in the documentation of my final project, but till then
i will update this list:
Trapeziodal-Screw: Left over from the MTM-Week: 0$
Electronics (Controler): Fab-Pic from the Hello-World-Assignment or a new one (sample): 0$
What parts and systems will be made?
The holder and heating for the syringe
The extruder and heating for the extruder
What processes will be used?
3D-Print and Lasercut for the first test-parts
Lathe for the most parts
LPKF-Mill for the electronics
Gypsum-casting for the isolation
What tasks need to be completed?
Drawing sketches on CAD
Design the feed for the reservoir
Mill the hardware
Design the electronics
Implement the PID for the temperature-controler
What questions need to be answered?
My main problem will be the milling of the archimedes-screw. I´ve got no clue how to build this part...
What is the schedule?
Due to my visit at the Fab12 my deadline is the 9.7....
1.6. - 11.7.: Make the drawings and buy material
11.7. - 25.7.: Building the parts
25.7. - 2.7.: Program the electronics
2.7. - 9.7.: Evaluate and making improvements
How will it be evaluated?
Well, this task is easy and not Weight-Watchers-Compatible. I think i will print a lot of
chocolate :) Yummi...
Now you should have an idea about my final-project. Stay tuned for news...
So long, have fun!