stepper motors for drawing robot

Maybe it would be better if stepper motors were used in the drawing robot. This is because the encoder motors would be adequately covered by the other projects, students would be introduced to stepper motors and the stepper motors would produce a far better result. The MKRMotor Carrier does support steppers.

I'm trying to get my daughter interested in STEM (showing not telling), and she sees the noisy result and is really not impressed.

These projects could be a great way to sell engineering to people thinking about engineering in high school but they have to be somewhat impressive. (I have not done the other projects yet)

However nothing really would prevent some one (such as myself) from doing this anyway and that is part of engineering. All that would really be needed is to 3d print a mounting bracket.....

An impressive result is an important means to the end goal of education, I fully agree. To that end stepper motors are a shortcut and there is not much to learn about open loop position control with steppers. On the other hand position control of a servo motor is rich in engineering concepts and the result can be better than with steppers it just takes a little investment in understanding the system and how to control it. Continue in your quest, you will see the incredible specifications of the components in the kit combined with your ingenuity can lead to a much more inspiring result to the layman after some perseverance. Note: much of the PID control details are not covered in the material but all the schematics and code are out there for you to play with if desired.