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  • Variable speed

    so now that I am somewhat hooked,I been reading a lot,and it's a given that variable speed is adventagious .there are several examples on the web of people using treadmill components for variable speed conversions on tools.is this viable?
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  • #2

    Re: Variable speed

    No info/experience re:treadmill/DC motors...
    however I had a spare 3ph motor and picked up a VFD off Amazon for $100.

    my Delta 1460 can now be dialed up/down to whatever RPM feels comfortable with the turn of a dial.

    wiring was easy, setup was easy, and rpm changes are easy too.

    I have a few 3ph machines/motors and am very happy with all of them.

    BONUS, reverse is easy too.
    bkrits likes this.
    [insert something witty here]

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    • #3

      Re: Variable speed

      It would have to be a very expensive treadmill that would yield a motor powerful enough to survive long service on a lathe especially if you want to turn bowls. If you don't mind scrounging used parts I suggest you go with a 2-3 hp 3 phase motor and a used vfd rather than old treadmills. You should still set up a jackshaft with large pulleys that will enable the motor to run fast enough to produce power and transmit it to the spindle.

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      • #4

        Re: Variable speed

        The 3-phase motor and VFD is the better way to get variable speed but people have used treadmill motors. Scavenging a motor and controller from a junked treadmill is likely to be very inexpensive and this made them attractive when VFDs were much more expensive than they are now.

        You have to be a bit leery of HP ratings if they are things like Peak or Treadmill rather than Continuous. Also, some motors run at high RPM which means reduction pulleys are essential but a pulley system may be a good idea for any motor to keep it in a good torque range. You need the controller board that powers the motor.

        billh

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        • #5

          Re: Variable speed

          If have quickly discovered free treadmills in perfect working order are ten cents less than a dime a dozen,not much to lose

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          • #6

            Re: Variable speed

            Check out this from Tool Fan [Rory] on using treadmill parts on a lathe. He could probably give you a good idea how long the components would last with use on your lathe.
            https://forum.canadianwoodworking.co...-46-wood-lathe

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            • #7

              Re: Variable speed

              Tore down the treadmill,motor is 2.75 peak hp,1.5 hp continuos duty

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              • #8

                Re: Variable speed

                Originally posted by Frank English View Post
                Check out this from Tool Fan [Rory] on using treadmill parts on a lathe. He could probably give you a good idea how long the components would last with use on your lathe.
                https://forum.canadianwoodworking.co...-46-wood-lathe
                I have been putting treadmill motors and 3 phase motors with VFD's on lathes for the past few years. What I have learned is that the HP rating on the treadmill motors is some theoretical maximum and is in no way what you might expect. Mass seems to be more important i.e. bigger motors are better.

                The control circuit board is also important. If you can find an MC 60 control board, it will work on any treadmill motor that I have found and deliver enough amperage to achieve sufficient torque at low speed. The MC 60 boards are on the older treadmills that have dials or slides to change the speed. Unfortunately these treadmills have the little "2.5 or 2.75 HP motors that are inadequate.

                Also important, is to keep the heavy flywheel on the motors. This usually requires some modification to the belt drive section of the flywheel. I generally turn that part down to 5/8" or 3/4" and attach a stepped pulley to that stub. The flywheels are sometimes screwed onto the drive shaft with a left hand thread. This needs to be secured with a set screw.

                The nice thing is that treadmills can be found for free. The not so nice thing is that sometimes 2 treadmills are required (one for the motor and one for the control board).

                Attached are a couple of motors that are perfectly adequate for a Beaver, Rockwell, Delta, Walker Turner lathes when combined with an MC 60 board.

                The second picture is just the label on the motor but it was the "best" one that I have encountered. Even at 100 rpm, I could not stop the spindle from spinning with that motor.

                VFD's and 3 phase motors are great (but not free). With VFD's it is possible to increase low rpm torque.

                I hope that this helps.

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                • #9

                  Re: Variable speed

                  Originally posted by tool fan View Post

                  I have been putting treadmill motors and 3 phase motors with VFD's on lathes for the past few years. What I have learned is that the HP rating on the treadmill motors is some theoretical maximum and is in no way what you might expect. Mass seems to be more important i.e. bigger motors are better.

                  The control circuit board is also important. If you can find an MC 60 control board, it will work on any treadmill motor that I have found and deliver enough amperage to achieve sufficient torque at low speed. The MC 60 boards are on the older treadmills that have dials or slides to change the speed. Unfortunately these treadmills have the little "2.5 or 2.75 HP motors that are inadequate.

                  Also important, is to keep the heavy flywheel on the motors. This usually requires some modification to the belt drive section of the flywheel. I generally turn that part down to 5/8" or 3/4" and attach a stepped pulley to that stub. The flywheels are sometimes screwed onto the drive shaft with a left hand thread. This needs to be secured with a set screw.

                  The nice thing is that treadmills can be found for free. The not so nice thing is that sometimes 2 treadmills are required (one for the motor and one for the control board).

                  Attached are a couple of motors that are perfectly adequate for a Beaver, Rockwell, Delta, Walker Turner lathes when combined with an MC 60 board.

                  The second picture is just the label on the motor but it was the "best" one that I have encountered. Even at 100 rpm, I could not stop the spindle from spinning with that motor.

                  VFD's and 3 phase motors are great (but not free). With VFD's it is possible to increase low rpm torque.

                  I hope that this helps.
                  thank you for your input
                  you did not comment on durability,do these treadmill motors pass the test of time?
                  the one I have,at 2.75 peak,1.5 continuos,is it enough for my lathe,or at least a drill press?

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                  • #10

                    Re: Variable speed

                    I have not heard of a motor failing. Post a picture of your motor with a ruler for reference and I’ll tell you what I think


                    Sent from my iPhone using Tapatalk

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                    • #11

                      Re: Variable speed

                      Lathe or drill press, they are about the same machine in my eyes.

                      In my opinion, you reduce the RPM of a motor and put large loads on whether DC or AC you need to watch the cooling.

                      My Lathe has a 3hp 1750 RPM motor on VFD with three belts.

                      My drill press has a 2 hp motor 865 RPM. It is geared 1 to 1 motor ratio to spindle. I overrun the motor to get up to 1200 rpm at the spindle. At 2 RPM you cannot stop that spindle, as I set the VFD in sensor less vector control... but the motor can get extremely hot in about 10 minutes.

                      Click image for larger version

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                      For every action there is an equal and opposite reaction.
                      Sir Isaac Newton.

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                      • #12

                        Re: Variable speed

                        Originally posted by Matt Matt View Post
                        Lathe or drill press, they are about the same machine in my eyes.

                        In my opinion, you reduce the RPM of a motor and put large loads on whether DC or AC you need to watch the cooling.
                        Not even close to the same in my view. A lathe in the hands of an expert slicing off rivers of wood for hours at a time is a near constant high demand application. It is difficult to load a drill bit for more than a few seconds at a time and at very low rpm the torque is limited by the drive train so the power (speed times torque) is also limited.

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                        • #13

                          Re: Variable speed

                          I agree, the operating characteristics between lathe and drill press are as Cole Porter said, "Night and Day". Younger members may Google Cole Porter.
                          billh

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                          • #14

                            Re: Variable speed

                            Originally posted by Matt Matt View Post
                            Lathe or drill press, they are about the same machine in my eyes.

                            In my opinion, you reduce the RPM of a motor and put large loads on whether DC or AC you need to watch the cooling.

                            My Lathe has a 3hp 1750 RPM motor on VFD with three belts.

                            My drill press has a 2 hp motor 865 RPM. It is geared 1 to 1 motor ratio to spindle. I overrun the motor to get up to 1200 rpm at the spindle. At 2 RPM you cannot stop that spindle, as I set the VFD in sensor less vector control... but the motor can get extremely hot in about 10 minutes.

                            Click image for larger version

Name:	A9C57B3F-8698-4CEC-A062-B7624532004C.jpeg
Views:	398
Size:	711.9 KB
ID:	1265887
                            You are absolutely correct about cooling. On the DC motors there is usually one and sometimes 2 fans that help keep the motor cool. However they spin at the same rate as the motor so at low speeds I am not sure that they are effective.

                            Nice setup on the drill press by the way

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                            • #15

                              Re: Variable speed



                              You are absolutely correct about cooling. On the DC motors there is usually one and sometimes 2 fans that help keep the motor cool. However they spin at the same rate as the motor so at low speeds I am not sure that they are effective.

                              Nice setup on the drill press by the way[/QUOTE]
                              Rory,
                              i have been doing a lot of reading today( home sick). One thing I came across was a thread from here a couple years ago where you said you were going to build a controller out of a 400w scr,a bridge rectifier,and a 5ohm potentiometer.
                              How did that work out?
                              Last edited by al.m..; 01-13-2020, 11:55 AM.

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