BT3000 Motor Question

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  • Lester Moore
    Forum Newbie
    • Jun 2012
    • 5

    BT3000 Motor Question

    Have had mine for around 12 years, on the second motor now. Bought used saw, everything for $75, changed out the drive assembly for the new/used one. Let it sit for a year. Recently built a shop, and started using again.

    Notice that new motor doesn't seem as powerful as original, gets bogged down cutting pine (3/4"KD). Cut a few boards today, and it just acts like its tired, no power.

    Is there a tune up I can do? Will be checking the brushes tomorrow.

    Thanks,

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

    #2
    probably things to check in the order of least involvement most likely first
    is
    1. Check the blade - a worn blade will give that tired saw syndrome. a freshly sharpened blade has rejuvenated many a saw.
    2. Check and make sure that the saw is plugged into a wall outlet and on a circuit that does not have any heavy loads in it. THe BT3000 has a 15A capacity when loaded which leaves nothing else sharing the same breaker or fuse.
    3. Make sure no extension cords are used, if you do they should be the 12 Ga. type and short. An improper cord, or a cord with bad plugs or lossy plugs amounting to 2 ohms (not a lot) can drop the saw voltage by 30V @ 15A leading to very tired operation.
    4. Alignment - if the blade guard riving knife is not aligned behind the blade (thats what the row of shims is for) then the knife can drag on the wood making it read hard to feed. Do you recall how to adjust this?
    5, Likewise if the rip fence is not parallel with the blade then the wood will become read hard to feed as it binds up.
    6. after that you have your motor problems like burnt windings, bad brushes, bad bearings, etc but these are really less likely if your saw has been running OK and not mistreated.

    Welcome to the forum, perhaps you should request my FAQ below.
    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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    • pelligrini
      Veteran Member
      • Apr 2007
      • 4217
      • Fort Worth, TX
      • Craftsman 21829

      #3
      Could Les have gone from a 15A motor to a 13A replacement?
      Erik

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      • Lester Moore
        Forum Newbie
        • Jun 2012
        • 5

        #4
        Thanks for the replies!

        Originally posted by pelligrini
        Could Les have gone from a 15A motor to a 13A replacement?

        Very good point, wonder if there is way to tell? I have done a little research today. Armature assembly - $136.26 Field Assembly - $37.90 I have everything else.

        I have been trying to recall which piece burned on the original motor. I am pretty sure it was the armature, as I threw it away. Still have the rest of the parts from original motor.

        A continuity test should tell me if the field assembly is still good right?

        Thanks again,

        Les

        Comment

        • mpc
          Senior Member
          • Feb 2005
          • 979
          • Cypress, CA, USA.
          • BT3000 orig 13amp model

          #5
          As Loring noted, issues with the electrical power to the saw are quite common. Extension cords, poor wiring to the wall socket, dirty contacts on the cords or inside the socket, etc. lead to resistance... and resistance multipled by amps is the voltage lost. A quickie test is to get a 3-way splitter and install that in the outlet on the side of the saw, plugging the stubby motor/saw cord into the splitter. Plug a small desk light - with an old fashioned incandescent bulb - into the splitter. Get a helper. Turn on the light and note how bright it is. Then turn on the saw. The light might dim for a moment (motor "inrush current") but it should return to the original brightness within a second or so. If not, either the motor is drawing excessive "idle" amperage or the wiring really sucks. Now start cutting a board while the helper watches the light again. (don't watch the light while making a test cut - your eyes need to stay on the saw, not on a light for safety!) If the light dims appreciably, think power supply issues. Try a different outlet, no extension cord, etc. It's amazing how different one outlet can be from another. Outlets with voltage drops need an electrician to figure out the "why" and fix it.

          On some boards, internal stresses (from the grain) cause the kerf to pinch shut during the cut... so the far end of the board grabs the back of the saw blade leading to excess drag. The splitter helps relieve this. As a test: cut part-way through a board and then shut the saw off. Then remove the board. If the kerf stays a constant width, the wood doesn't have internal stresses. If the kerf tries to pinch shut, it's the problem - and it can be a dangerous problem. Pinching the blade is one source of kickback! The kerf may expand too; that means one (or both) sides of the board are flexing away from the cut - possibly into the saw fence. Since the fence won't move, that flexing instead shoves the whole board into the side of the blade ==> friction and possible kickback.

          mpc

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