We first wrote about Shane Colton’s TinyCross ultralight electric crosskart back on August 27, 2018. Since that time some upgrades have been in the making.

I’ve been waiting over a year to see if this mountain bike air shock suspension setup would work, and it looks like it does! I haven’t done any tuning on it besides setting the preload, but it handles my pretty beat up parking lot nicely, absorbing bumps that would have broken tinyKart in minutes.

The steering linkage also seems okay, with good travel and minimal bump steer. There are still some minor mechanical improvements I want to make, but it’s nice to see the suspension concept in action after all this time.

And any good vehicle these days gathers data on performance:

One of the early lessons I learned in building motor drives is to always log data. Nothing ever works perfectly on the first try, but having data logging built in from the start is the best way I know of to quickly diagnose problems. A lot of the stuff that happens in a motor drive is faster than typical data logging can capture, but a lot of it is also periodic. By synchronizing the data collected to the rotor electrical angle, its possible to reveal detailed periodic signals even with relatively low frequency (50Hz) logging to an SD card.