This instructable is about building a cartridge extruder and having my first experience using a laser cutter. A fun project to mix 3d food printing tools with my learning process here at Pier 9. For testing purposes I also build a stand to hold the extruder, and since we were already in the mood, it was laser cut too.

I am attaching both .svg files and the .igs file from Fusion 360, first time using it!

To build your own you will need:

Laser cut parts
Cartridge and piston
A non-captive linear stepper motor Nema17, make sure the shaft is longer than 7 inches
4 x m3 10mm bolts (to hold the motor)
4 x M3 25mm bolts and nuts
1 x M4 20mm bolt and nut

Step 1: Assembling It

Gather all the parts. I highly recommend following the pictures rather than reading.

Attach the motor to the motor plate using the 10mm length M3 bolts
Insert the vertical holder through one of the lateral-centered slots. In the other one insert the vertical spacer. Make sure the long part of the vertical holder is on the motor side
insert the cartridge plate using the slots into the vertical holder and spacer
Lock both plates using 25mm M3 bolts and nuts
Insert the piston into the cartridge.
Test that the cartridge slides tight in between the two plates
Insert the M4 bolt into the shaft holder slot
Screw the shaft through the stepper motor until it locks into the piston
Make sure the flat side of the shaft end is parallel but on the opposite side of the vertical holder
Slide the shaft holder through the vertical holder and the end of the shaft too. The flat side should coincide with the nut
Tight the M4 bolt, to fix the shaft holder to the shaft

And that's all you need, now you have your assembled extruder.

Step 2: Buiding the Stand

Si no quieres caldo toma 2 tazas. Abusing the laser cutter for this project was the goal, and this stand is a probe of it. It is pretty straight forward to assemble.

Make sure to loose the bolts connecting the plates before to start
Slide in the lateral walls
Insert the lower and upper beams and tighten again
Now we are ready to test it!

The upper front beam is not really mandatory and it DOES block loading and unloading the cartridge. Also tiny pieces of paper can be helpful to have tighter laser cut fit-joints.

Step 3: Let's Have Some Fun Aka Testing It

Time for some testing! I tried two different materials.

The first one was cream cheese chives and onions. It was too thick, even if the motor could at some point extrude it, eventually it started skipping steps.

The second food extruded was artichoke spinach hummus. This was way thinner and easy to extrude, but had some chunks that clog the nozzle.

The hummus was easier to extrude so I decided to have some fun doing some "manual" test prints. 2 3 2.

Step 4: Controlling the Motor

To control the motor movement during the previous experiments I was using a computer and a Smothieboard. Those are great tools for a 3d printer, but not really convenient for a single motor. That is why I build a single box to control speed and direction of the motor without the need of a computer.

Parts:

Laser cut parts
Arduino Uno
2 arcade buttons
Linear potentiometer
Adafruit motor shield
2 x M3 12mm
4 x M3 16mm
2x M3 8mm
3 x M3 nuts

Follow the pictures to assemble it.

Added to this step can be found the .svg file to laser cut the parts, and the Arduino sketch.

The controller has two buttons and one slider. The buttons are used to control the direction of the extruder. One click on the left one extrudes, on click on the right one retracts. Clicking both at the same time stops the extruder. the slider allows to adjust the shaft speed.

stepper_control.ino
Download

Step 5: Last Test Filling Raspberries

To test the controller we picked a simple sweet and delicious recipe. Raspberries filled with whipped cream topped with cocoa powder. Maybe a small mint flower garnishing on top would had been great too.

Watch the video to see the extruder in action.

Step 6: Conclusions

This extruder design has been great to learn how to use the laser cutter. The extruder itself is super simple to design, modify, build or use; GOOD POINT. A big drawback is that is not really strong. It is not able to extrude thicker pastes or dough. Great for thin consistencies as mashed potato or meringue. I have the feeling is gonna be a great tool to rapidly test different material.

Hope you enjoyed.

If you want to build one, and you are around San Francisco let me know I might have some spare cartridges and pistons for you :)