3D Crayon Printer




Introduction: 3D Crayon Printer

About: I am a 15-year-old DIY hobbyist. I mainly focus on electronics, but I dabble in other areas as well. (If you noticed my profile picture I also am a crypto enthusiast)

I want a 3D printer very badly, but I have no money. I'm also 13 and can't get a job, so what do I do? I build one out of Legos. Unfortunately, I do not have Lego Mindstorms ($350), so I had to make do. This is not meant to be a precise or accurate printer. It is a tool for artwork or sculpting. Let's get started!

Step 1: Gather Materials

Here are the materials and tools you will need:

  • 4 Small Craft Motors (Amazon)
  • 2 Big Craft Motors (Amazon)
  • Thin twine (Amazon)
  • 2 9v Batteries (Amazon)
  • 2 9v Battery Connectors (Amazon)
  • 3 Momentary Switches
  • Small Breadboard (Amazon)
  • Electrical Tape (Amazon)
  • Wire Connectors (Home Depot)
  • Copper Speaker Wire (Amazon)
  • Lego Baseplate (Amazon)
  • Assorted Color Crayons (for Filament)
  • Funnel
  • Lots and Lots of Legos!


  • Hot Glue Gun
  • Soldering Iron

Step 2: The Frame

Now we're going to build the frame of the printer. I know this step is not very helpful, but that is only due to the number of pieces. Build the frame with two pillars supporting a rectangle on the platform, as shown above. Now on to the extruder. I built it in an "H" shape, with two long rods supporting the center. In the center of the extruder there is a hole (about 2cm x 2cm). Line the hole with hot glue to keep the melted crayon (filament) from sticking to the nozzle. For the bed, make a rectangular platform that is about 8cm x 13cm with walls on the side (see picture). Also, I put down smooth pieces on the bottom of the bed to give it a more appealing look.

Step 3: The Motors

Now we can put the motors down. First, solder leads to the motors if they do not already have any. Next hot glue all of the motor shafts to the shown Lego Technic piece (refer to graphic above). Now hot glue all six motors, with the Lego pieces on them, on to 2x4 Lego planks (picture above). Now place the planks on the printer as shown in the picture.

Step 4: The Cords

Now it's time to break out the twine. This step is simple. First, attach a Lego Technic axle (above) to the piece on the motor shaft. Measure out the distance from each motor to the other side of the green platform and cut some string to that length. Now tie and got glue the corresponding string around each axle, as in the picture. Connect (with hot glue or Legos) the end of the two small motors' string to the side of the extruder (video above). Now tie and glue twine to the big motors' shafts. Connect the twine to the bottom of the bed (picture above).

Step 5: Wiring

Now it's time for the wiring. Get out the tactile switches and a bunch of jumper wires. Put the switches on the mini breadboard as shown above. Now take all the negative leads on the motors (black) and connect them, along with another black wire, with a large wire connector. Connect the remaining black wire to the negative connection of a 9v battery clip. Now connect the positive (red) wire of the 9v battery clip to the black wire of the other clip (picture above). Now fasten the remaining red wire to a colored jumper wire. Place the jumper wire on A10. Put 3 other jumpers in the same row. Connect one of the wires to the A7 point on the breadboard. Connect the wires in the '10' row to the right prong of some of the switches. Do the same for jumpers in the '7' row. There is a picture above. Now connect each red lead from the motors to jumper wires, and connect the jumper to the other end of the momentary switch, as shown above. That's about all.

Post Script: Connect the batteries when you want to power it up. You can also wire in a switch if you want.

Step 6: Melt Crayons!

Now it's time to melt some crayons. You can use whatever color you want, just don't mix complimentary (opposite) colors. Take the labels off and cook them in a pan (separately from the zucchini). The melted crayon will be your filament.

Step 7: Use!

Now all you have to do is hot glue the rubber funnel onto the extruder. Finally you can pour the filament with one hand and operate the buttons with the other. Happy Making!

Post Script: The 'print' that is shown in the picture is my first, so it is kind of abstract. In honor of the Colors of the Rainbow contest I used three different colors. I switched filaments half way through.

Colors of the Rainbow Contest

Participated in the
Colors of the Rainbow Contest

Be the First to Share


    • Robots Contest

      Robots Contest
    • Micro:bit Contest

      Micro:bit Contest
    • Halloween Contest

      Halloween Contest



    Question 1 year ago on Introduction

    Trying to order the motors for this project. Could you give us more details about the motors?
    And is there a specific momentary switch you found to be best?


    Answer 1 year ago

    The specs of the motors really matter. The ones I used were all salvaged from old remote control toys if I recall correctly. As long as they can move the extruder assembly around, they work. Honestly, I did this project when I was very inexperienced and had no clue what I was doing, so it was thrown together kinda haphazardly.
    As for the switches, it doesn't matter at all what kind they are. The links for the motors and switches similar to the ones I used are in the intro.


    Reply 1 year ago

    Thank you. my 13 year old is excited to get started.