Who got this shaft?
You can say one thing for sure about the drive shaft held here by Raven Engineering Inc.’s Jeffery Hanft: It didn’t come off a NASCAR racer. The reason you can tell is the small bump on the shaft Hanft points to. It is actually a weight added to the shaft by an automatic welder. It was added to balance the shaft once the shaft had been measured in one of Raven’s automatic balancing machines, which are specifically designed to gauge shaft vibrations and calculate where to add weight to get rid of them. The small spot of weld material comes from welders on the machine that work automatically based on the vibration profile. But NASCAR racers don’t want pieces of weld on their drive shafts that can fly off at high revs. So instead, Raven balances drive shafts on the race cars by removing small amounts of material, usually on the ends of the shaft. That operation, too, is completely automatic.