If you have larger diameter material between centers it often happens that the drive spur is slipping. Her is Oneways solution: The Big Bite Chuck Spur. This spur is mounted in the jaws of a Talon or Stronghold chuck. Note that you put the two teeth of this large spur perpendicular on the grain so that the wood will not split.
The big spur fits in all Oneway, Talon and Stronghold chucks.