I modified the original carriage to accept the timing belt approach. To do this I had to rotate the drive motor 90 degrees and mount a timing pulley on the shaft. The belt needs to thread through the carriage sides, and since it forms a loop, there are two holes on each side. The belt needs to be attached to the drill platform and loops over the timing pulley on the drive motor. The other end needs to wrap around a free turning idler bearing (or a very smooth/no-friction surface). Read more…