Motor prototype

Posted on October 1, 2017

After obtaining a stepper motor, the first thing to do was for me to learn how to control its rotation from an Arduino board.

The motor itself requires 12v, and the Arduino only provides 5v. Rather than dealing with live wires and risking overheating the motor—or hurting myself!—I added a rocker switch to my power supply, so that I could control it.

From here, I could connect all the hardware together and simply follow a tutorial on controlling the motor rotation. As usual, I tend to want to edit the tutorial code so it is more to my liking. I ended up creating a Processing program that would send commands to the Arduino to rotate the motor when a key is pressed. I haven’t posted it yet on Github, as it’s a bit of a mess, but I may do it later.

The Arduino tutorial uses the Stepper library, which works as intended, but I found the AccelStepper library which seems to provide more control. There seems to be an API to control the motor at a very low speed, which would be quite useful for my project.

Prototype

And so I have a plan for the prototype I want to build, as presented in the sketch above.

The only issue at this point is to find the screws that will go through the motor to hold it in place. The Concordia metal shop technician helped me figure out that they are 3mm x 0.5 (metric) screws. So now I need to build the wooden case so that I can calculate the length of the screws.

Once all that is in place, I would be able to consider drilling a hole in the motor’s metal peg and pass a guitar string through to see if the motor is able to rotate, or if it stalls.