3D Chocolate Printer Made From LEGO




Using lego and a few custom components a 3D printer for chocolate is possible. I did this project a long time ago so the documentation is incomplete, but hopefully it will inspire someone to rebuild it and fill in the blanks.

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Step 1: Make a Chocolate Extruder.

These were my first rough plans for a chocolate extruder. Powdered chocolate into a heated barrel, lego worm screws as the slurry pump through an ejection nozzle.

Step 2: Cut Extrusion Chamber

bandsaw - 1" x 1" x 3" aluminum extrusion

Step 3: Drill and Reem the Bore Hole for the Worm Screw.

I can't remember the diameter, but it was a close tolerance fit for the lego worm gear (close to 1/2in) Nice thing about lego is that it is super high tolerance!

Step 4: Cartridge Heaters.

4 x 5W bar heaters to supply the heat to melt the chocolate. I think there are cheaper solutions, but there were convenient and fit nicely in 1/8in holes.

i got mine from watlow:


Step 5: Interchangeable Nozzle and Set Screw

I put an interchangeable nozzle and set screw in the end of the chocolate extruder. the idea was this would make it easier to change the diameter of the chocolate bead being extruded as well as making it easier to clean out the chamber as necessary - like when chocolate melts solidly inside it...

Step 6: Cartridge Heater Positions Around Extrusion Chamber.

i placed the cartridge heaters around the extrusion chamber like so. I need a jobbers drill bit to drill the 1/8in holes deep enough.

Step 7: Fully Assembled Extrusion Chamber.

again, in theory the lego thermometer and programmable brick should be enough to do the chocolate control, but i used the PID and thermocouple because i was just interested in proving the concept and i had those lying around my lab.

Step 8: Testing the Extrusion Chamber

Here i am testing the extrusion chamber.

Step 9: Build a Lego Gantry

I can't remember all the details, but it's pretty simple. i used rack and pinions for the X and Y axis gantries.

there are lots of ways to do this. You really want z axis too. i hacked the Z axis by using a layer by layer increment ratchet that was mechanical. given the memory limits of the PCX bricks, one layer was about all you could program before having to upload a new layer code anyway.

Step 10: Lets Build Some Chocolate Stuff!

Here's the finished (well, you know, in a rough prototype kind of way) printer.

there are only 3 controllable ports on the rcx brick i used, so one for x, one for y, and one for the extrusion control. you'd need to gang two rcx bricks to further control temperature and the z axis.

I did end up doing 5 layer builds of 3D things like the letter A. unfortunately without a release / support material the geometry is limited, but it was still cool.

hopefully someone will rebuild this and simplify it.

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83 Discussions

Hello! We love Lego's and we also have a small chocolate business. I'd love to discuss a collaborative project. Contact me. linda@chocologyunlimited.com


6 years ago on Step 10

Ok this is pretty genius, but what about 3D objects? Does the chocolate stay hot for too long? How about a cooling fan after the drip nozzle? Ultimately I think printing a chocolate bunny would be the benchmark for this awesome machine.

3 replies

Reply 5 years ago on Introduction

a year ago i know but..... pressurize the chocolate rater than melt it? i remember seeing a cool idea ages ago about putting chocolate through a plastic injection molding machine... the result chocolate is fluid a high pressure but sets quick. this was an idea to aid chocolate manufacture and de-molding times but might work in a 3d printer :)

hhmmmm, i feel my cnc router/plasma cutter project taking a side step. I think i can make a safe machine that can cut both metal and plastic with out setting the place on fire but the chocolate might have a few chips in it.....


6 years ago on Introduction

3D printer just to market is relatively expensive, after all, is a technology that has just started, manufacturing cost is relatively high, after a period of time,technology is more and more popular, the price drop. Consumers consider theother countries of the brand, the price is relatively low, such as LXMaker.Interested in 3D print can log onto the http://goo.gl/6l6j29 or http://goo.gl/2wt6LU view details.

Jacky P

6 years ago

Can you add a parts list?


7 years ago on Step 10

what does it do?

If someone makes a chocolate printer, You would think they had an example.
Maybe" Step 10 - Lets build some chocolate stuff!" is not finished?


7 years ago on Step 10

haha, i was just using my labs 3d printer and then saw this article so i figured i'd give it a read :) support material would be hard to do for this one :( i use a special type of plastic that desolves in a special acid bath and leaves the structural material behind :)


8 years ago on Introduction

Hey there,

I would love to see your project in the 3D print group I have just started!!!!



8 years ago on Introduction

omg - smh - pfa (pretty friggin awesome) - this is sweeeeeet!


9 years ago on Introduction

i know for sure that you can get some in the starwars ships with opening wings, maybe you can find some in technix sets (i think thats what they are called anyways)

1 reply

8 years ago on Introduction

Great Instructable - well done! For those who are interested beyond lego, head to Makerbot Industries for a frosting extruder and RepRap for a plastic extruder to bolt onto this lego design. I'm going to put this extruder on my cnc project!!!!!

1 reply