iWW08 Show Notes

iWW08 Show Notes

Notes for Episode 16 - Changing Out a Bandsaw Blade

After the long absence, we're back with more episodes of the iWoodWork Podcast.
  • Life is good, I'm working at Marc Adams School of Woodworking full time, only thing I need is...more time.
  • Big Congrats to Wes our behind the scenes editor and cameraman extraordinaire.
    • He and his wife are now officially parents! Congratulations are definitely in order.

In this episode, we look at how to set up a bandsaw with a new blade. In this case, I’m setting up the bandsaw to resaw some lumber.
  • Along the way we’ll look at all the parts of the bandsaw
  • Then we will change the blade and adjust all those parts

Parts of a Bandsaw
  • On the Back of the Upper Housing
    • Tension Control - A sliding bracket, containing a spring, provides tension to the saw blade by rising or lowering the bracket. The box connects through the Upper Housing to the shaft of the Upper Wheel
      • Tension on the spring is controllable, More tension is needed for larger blades
      • Note: Don’t leave tension on your bandsaw. Can affect the shape of the bandsaw tires
    • Tracking Control - A wing nut allows me to change the angle of the upper bandsaw wheel
      • It allows me to control where the blade rides on the upper wheel.
      • You center the blade on the wheel otherwise it will try and run forward or run backward. If it’s really far off, it will jump off the wheel
        • Podcast goof - it sounds like I’m suggesting the blade can waver back and forth - NO. It’s one or the other
    • Quick Tension Release
      • An option on many bandsaws. Quickly releases tension without having to change your setting on the spring
  • The Top Wheel
    • Has a urethane tire which the saw blade rides over
  • The Guides
    • Blade guard - always unplug saw when guard is off or doors are open
    • Guide Post - raises and lowers to accommodate the thickness of your stock
    • Thrust Bearing - located to the back of the blade, prevents the blade from backing up when cutting pressure is applied
    • Guide Blocks - prevents the blade from twisting or racking too much while cutting
      • There are Guide Blocks and a Thrust bearing for the Bottom Wheel as well
  • The Bottom Wheel
    • Similar to Top Wheel, except it’s position is fixed, doesn’t float under tension, connected to the driveshaft
  • Table and Trunions
    • Knobs on the trunions allow the table to be set at an angle
    • Throat Plate - sacrificial disc of wood, metal or plastic, surrounds the blade

Changing Out the Blade

  • Remove Tension on Blade
  • Remove Blade
    • Remove the Table Pin, Walk the blade through the slot in the table
  • Back the Thrust Bearings and Guide Blocks away from the path of the new blade (upper and lower)
  • Put on new blade - I’m putting on a 1/2" 3TPI bandsaw blade
    • "Teeth pointing down" goes a long way towards not feeling like an idiot Winking
    • Centered on the tires
  • Put light tension on the saw blade
  • Slowly rotate the upper wheel and adjust the Tracking Control until the blade is riding centered on the tires
    • As you dial in, speed up the rotation - magnifies any drift
    • Tune position so that the teeth on the blade ride just forward of the crown (high-point) on the tires It’s the solid steel portion of the blade that you want centered
    • When the blade stays seated in the center position at during faster revolutions, it’s dialed in
  • Position the Thrust Bearings - move bearing forward
    • Want only occasional blade contact with the bearing
  • Reinstall Guide Blocks
    • Not in contact with the blade
      • Think a dollar bill’s thickness away
  • Position Guide Blocks - move them forward until the forward edge is at the bottom of the gullet in the blade
    • "Teeth not Eating the Blocks" goes a long way towards not feeling like an idiot Winking
  • Listen to the sounds a bandsaw makes as you are tuning it.
  • Make sure all set screws are snugged down
    • Don’t forget to check below the table
  • Retension Blade
    • Spring Scale is very rough estimate
    • It’s more about the sound of the bandsaw and ultimately, the quality of the cut
  • Replace Guards and Table Pin
  • Check that the Table is square to the blade
  • Please: Make any necessary tweeks only under human power, not motor power!
  • When you are satisfied, give it power.
    • You should be hearing a nice rhythmic hiss

Square the Bandsaw Fence to the Drift of the Blade

  • Verify / Measure Drift
    • Freehand cut a board part way along a line that is parallel to the edge of the board
    • Draw a line on the table down the edge of the edge of the board
    • Line the Bandsaw Fence up along the line drawn on the Table
      • If the fence is parallel, you are done
      • If it isn’t parallel, adjust the fence according to your user manual

Next time...Resawing Thick Lumber to Create Matching Panels!