So, nothing big, this is just something I found recently. I built this like, 5-6 years ago. It's a drill tank that runs on an older motor, the one that has a separate battery pack. I used the forward outlet to attach a rod that spun perpendicular to the rest of the build. Facing forward, it was a drill. I should probably recreate it and do it better, but at the time I was really proud of it. This is probably my first big K'Nex achievement.