Sometimes you see something on the internet and you just have to know more about the inception of the concept. For example, watch this cat ride a custom electric skateboard. We can probably all agree that it is awesome, but I can’t help but wonder why it was built, or how the heck you’d train a cat to even do that. I caught up with Kim Pimmel, an interaction designer for augmented reality at Adobe, and asked him about his project.

Why did you build this? What was your inspiration here?

I like to experiment at the fringes of UX design such as immersive interfaces in AR/VR, voice UX, or ML-driven design.

As a cat owner, I’ve been curious if I could create interfaces for my cat MIDI. My Pet Projects series investigates whether she can learn to use affordances such as buttons, levers and switches with a treat as a reward. So far I’ve made a robo-dog thing that gives out a treat when its nose is pulled  and a  machanical pinball machine – both of which she learned pretty quickly.

 

The latest project, an electric skateboard I built, has a throttle lever with a hole in it where treats go. Put a treat into the throttle lever, and she pulls it to get a snack and give the board a boost. It uses an Adafruit Feather microcontroller to sense is the throttle is pulled, and the Adafruit Feather DC motor featherwing to drive the motor on the board. It uses a high torque 2000rpm electric motor to move the board.

How did you build it? How long did it take?

The skateboard is a standard deck with chunky wheels for a smooth ride, and the drivetrain is an off the shelf electric skateboard belt system for longboards.

The throttle lever housing and electronics box were prototyped and built using a Glowforge to create the parts. The wooden throttle housing components were glued together with CA glue and baking soda for structural strength, sanded and painted to give it a finished look. The treat tray parts were cut from black acrylic since it doesn’t absorb food particles or kitty saliva, and can be easily cleaned.

The project took several weeks to complete and went through multiple rounds of prototyping – from lo-fi proof of concept to polished final result. The very first version was a quick proof of concept made using a kleenex box and spare parts from the studio

 

That first POC used a capacitive touch sensor for the throttle, which worked great and was easy for her to use, but lacked the visual satisfaction of her pulling on a throttle to get the board moving.

What was the toughest part?

The hardest part of the build was finding the right motor that balanced torque and speed – it had to be strong enough to move the board and the kitty, but not so fast that she got spooked or crashed into things at high speed. I also didn’t want to spend too much on an out of the box electric skateboard motor system – that would also take the fun out of trying to make something custom. I tried several motors,finally settling on a brushed 2000rpm DC motor that the Adadruit DC motor featherwing could drive at both slower and faster speeds. I learned that DC motor control is a much more complex thing than I realized, and that easing into acceleration is key to a smooth off the line speed boost.

If you were going to build this again, what you do differently?

If I had to do something differently, I would have designed the electronics box so that it was easier to get into and tweak. It’s a bit difficult to get into, and has to be unscrewed from the board and flipped over to access the wires / battery / etc. Ideally there would just be a way to pop open that electronics box with a lid or access door.