Bandsaw purchase help

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  • LinuxRandal
    Veteran Member
    • Feb 2005
    • 4889
    • Independence, MO, USA.
    • bt3100

    #16
    Originally posted by LCHIEN
    I agree with DD that 220V doesn't confer smoothness. The only thing 220V really buys you for the tool itself is allowing power higher than you can get with a 110V standard circuit, e.g. more than about 1.5-2HP.

    For your shop it can also reduce wiring requirements to some degree.

    THere's just a lot of misconception of the advantages of 220V tools.

    I'd like to modify the above. Typically, if something is designed for more then 2 HP, it might also have more structure to it (verses trying to later wire a 220 and then swap the motors to something larger). Frames might not be the same. (indirectly connected, but still important)
    She couldn't tell the difference between the escape pod, and the bathroom. We had to go back for her.........................Twice.

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    • LCHIEN
      Internet Fact Checker
      • Dec 2002
      • 20914
      • Katy, TX, USA.
      • BT3000 vintage 1999

      #17
      OK, lets put it this way:
      if you need 2-1/2 or 3 HP or more, you have to get a 220V motor, you can hardly get 110 wired motors because the standard circuits won't supply enough current.

      If you have a motor that is in the range of 1-1/2 to 2 HP it can probably run off 110 or 220 and so may have dual windings that have to be properly selected. Then and only then do you have a choice of using 110 or 220. In this case, assuming properly sized wires and all are installed then there will really be no noticable difference in operation of the tool itself -Not smoother, not more powerful, not faster or slower. Using 220V would confer some differences in how you might wire your shop. You could potentially use smaller wires saving money. Or you could run two 1-1/2 to 2 HP tools off one branch circuit as opposed to only one on the 110V circuit saving a breaker spot and cost.


      Two-phase vs 3-phase:
      I don't know that really a 3-phase motor will be any smoother than a 2-phase - the induction field will be rotating at the same rate 60 Hz or 3600 RPM so it seems unlikely to me. The advantage that 3-phase incurs is that the fields rotate in a specific order so starter capacitors and centrifugal switches and the cost, unreliability and complexity, and residual power loss associated with them is removed. The phases stay balanced. However this is also virtually a moot point for home shops because homes almost always do not have three phase power available to them, only industrial plants.
      Last edited by LCHIEN; 08-05-2014, 11:34 AM.
      Loring in Katy, TX USA
      If your only tool is a hammer, you tend to treat all problems as if they were nails.
      BT3 FAQ - https://www.sawdustzone.org/forum/di...sked-questions

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      • woodturner
        Veteran Member
        • Jun 2008
        • 2047
        • Western Pennsylvania
        • General, Sears 21829, BT3100

        #18
        Originally posted by LCHIEN
        Two-phase vs 3-phase:
        I don't know that really a 3-phase motor will be any smoother than a 2-phase - the induction field will be rotating at the same rate 60 Hz or 3600 RPM so it seems unlikely to me.
        3-phase motors do tend to run smoother, but it's more because they typically have more poles than any inherent advantage with 3-phase.
        --------------------------------------------------
        Electrical Engineer by day, Woodworker by night

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        • LCHIEN
          Internet Fact Checker
          • Dec 2002
          • 20914
          • Katy, TX, USA.
          • BT3000 vintage 1999

          #19
          Originally posted by woodturner
          3-phase motors do tend to run smoother, but it's more because they typically have more poles than any inherent advantage with 3-phase.
          more poles make the motor turn at higher RPMS, single pole gives 3600 RPM, two poles gives 7200 RPMs, and yes that probably would make them smoother, however you can get single phase motors with two poles that would probably be equally smooth.

          I have some sneaking suspicion that people equate phases with cylinders in gasoline motors. In combustion engines 8 cylinders are smoother than 6 that are smoother than 4. 12 cylinders runs like a dream! This is because each cylinder fires once per revolution.

          If phases were like cylinders then yes 3 times as many would be a lot smoother with 3 pushes per revolution rather than 3... But phases are not like cylinders, poles are more like cylinders as discussed above.
          Loring in Katy, TX USA
          If your only tool is a hammer, you tend to treat all problems as if they were nails.
          BT3 FAQ - https://www.sawdustzone.org/forum/di...sked-questions

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