This morning, tired of the belt slipping on the driven pulleys, I removed both pulleys and put a full knurl on the face of each one. I left the center (idler) pulley with a plain face. The head pulley is still smooth. I find that although the set-up is great for demonstrating the fact that I can reverse the output shaft by shifting the belt from side to side, it isn't that great if there is much of a torque load on the output shafts. More experimenting this morning showed that sometimes it could drive the funky corner joint mechanism, and sometimes it wouldn't. The engine wouldn't stall out, but the belt would slip on the head pulley about half the time, unless I grabbed one of the wheels on the funky corner joint and "helped " it to get rolling. I think this is purely a result of the vacuum cleaner belt that I am using as my flat belt. Anyways, this has amused me for a couple of weeks, and we've had a bit of fun with it.---Brian