When welding on bits and bobs around the shop, it can be quite useful to have a full range of angles at which you can clamp your object. There are special tools, called 3 way vises that can tackle this task fairly easily, but then you still have to deal with the workbench they’re attached to.
Claude Ouellette took a rather inventive approach to creating a welding rig which involves an old motorcycle jack, a bowling ball, and a couple disk brakes. As you can see in the video above, when the jack is engaged, it clamps the bowling ball in place, locking the position of the welding clamp. When the jack is released, the ball acts as a giant pivot point allowing a very wide range of movement of the clamp.
In this 2nd video you can get a glimpse of how the whole contraption was made. What a great idea and fantastic execution.