My feeling is buy one of those 4 x 6 Chinese or Tiawanese horizontal bandsaws. They are more productive than the ones you build and end up not costing that much more than a homebuilt. I built a vertical metal cutting bandsaw and was happy with it till I was given a broken Jet horizontal bandsaw for free. Turns out it only needed the brass spur drive gear (the worm is hardened steel and usually does not wear out) which I ordered from Jet for about $30.00. It was more accurate, more versatile, and required much less adjusting than the homebuilt, Plus you can flip up the arm and use it as a vertical bandsaw. Usually the brass gear is all that is neede to bring them back to life.