Introduction: SiRo - a Simple 3D Printed Robot for Micro:bit

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About: I am a former teacher at a danish bording school. I used to teach tech, making, creativity and innovation. Now I mostly design projects for students and makers and educational materials for teachers.

SiRo stands for Simple Robot and is the smallest and simplest robot I could make for 3D printing. It is relative fast to print and easy to build. The parts are cheap and the robot can be disassembled so that the parts can be reused for other projects, making it a great robot for education.

Supplies

Materials:

Micro:bit

Motorbit

4 x M3 30mm screws

6 x M3 6mm screws

8 x M3 Spacers - I use 4x6 mm and 4x8mm

10 x M3 nuts

1 x Caster wheel

2 x TT130 motor

2 x Wheels for the TT130 motor

1 x 9 volt battery + baterry holder

A bit of wire. In two different colours if possible

A small piece of double sided tape

Filament for the 3D-printer

Tools:

3d-printer

Soldering Iron

Screwdriver

Wirecutter

Attachments

Step 1: Print the Chassis

First step is to slice the stl file in your favorit slicer and print out the chassis.

Attachments

Step 2: Solder Wires on to the Motor

While waiting on the 3d printer you can start by soldering wires on to the motors. Take 4 pieces of wire, each should be 12 cm, strip them and solder them on to the motors. If you can, then I would advice you to use two different colours of wires. It just makes it easier to keep track of them.

Step 3: Start Screwing It Together

We first take 2 of the spacers(8mm) and 2 of the 6 mm screws. Use the screws to install the spacers in the holes in the middle of the chassis.

Step 4: Add Coaster Wheel

For this step we need 4 spacers (6mm), 4 screws and 4 nuts.

Coaster wheels tend to be a bit short, so they need the spacers so the Robot is more straight. So first use the 4 nuts to install the spacers on to the chassis. Then use the screws to install the coaster wheel on to the spacers.

Step 5: Install Motors

For next step we need 4 x 30 mm screws, 4 nuts and the motors.

Install the motors as shown on the picture.

Step 6: Motorbit

We now take the last 2 spacers(8 mm), the last 4 nuts and the motorbit. First install the two spacers on to the motorbit, using the holes closest to were the microbit gets installed with 2 of the nuts.

Then install it on the chassis using the last 2 nuts.

Step 7: Wheels

Now add wheels to the motors. You should be able to just press them on.

Step 8: Wiring

Cut the wires so that they are as short as possible. Then screw the two wires from the right motor into M1 + and M1 - and the two wires from the left motor into M2 + and M2 -.

Step 9: Battery

Screw the battery holder into the motorbit. Black wire to GND and red wire to VIN. Then take your small piece of double sided tape and place it at the rear of the smar car and put the battery on top of it.

Step 10: Microbit and Programming

Now program the micro:bit. Remember to use the motorbit extension. Put the micro:bit into the motorbit and you are ready to go.