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Just Another Marble Robot (JAMR)

Just Another Marble Robot (JAMR) is a very simple Arduino based, 3-axis robot that you can build yourself as a school project or as a fun project with your kids. This robot will make your marble track much more interesting.

Despite being tiny it has all the stepper functionality of a larger robot including a high accuracy. With a ramp-up and ramp-down function it moves much smoother that servo controlled robots.

The robot is based on the inexpensive 28BYJ-48 12V stepper motor with the ULN2003 driver that you can buy for around €/$4,- per set. In combination with an Arduino Uno the total cost for this project is around €/$32,-.

On this page you will find all the needed information to start building the robot.

The parts that you need for this robot are:

  • 6 x 28BYJ-48 12V stepper motors
  • 6 x ULN2003 drivers
  • 1 x Arduino Uno
  • 1 x 10k resistor
  • 1 x BC547 transistor
  • 1 x coil from a 12V relais
  • Some M4 threaded nylon rods
  • Some M4 nylon nuts and bolds
  • An enclosure for the electronics
  • Some 0,14mm2/26AWG wiring


Download the JAMR wiring diagram

Click on the image to download the schematic in PDF-format

Download the JAMR STL files

Click on the image to download the STL files

Download the JAMR Arduino program

Click on the image to download the Arduino program