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treadmill teardown for dummies

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  • treadmill teardown for dummies

    The treadmill question comes up a lot here .. so .. I threw this together hoping to help someone.

    I tear apart a lot of treadmills. The main reason is for the motors and the controllers. There is a lot
    of other neat stuff (belts, tubing etc.) but that is the main reason.

    There are two "types" of controllers. Analog control and Digital control.

    Analog control is just a fancy way of saying that the speed of the motor is controlled by a
    potentiometer either a round volume type or a slider type. These are the ones that you
    want. These are ready to use right out of the box so to say.

    Digital control means that you need other circuitry to provide pulses to the controller board
    to control the speed. This additional circuitry is not extremely complicated .. but ... I prefer
    the ready to go analog controllers.

    You can easily tell which is which before you buy and get it apart.

    Here are some examples of the analog machines. Note how there is a knob or a slider.



    Now look at these ... the digitals have touch controls .. usually up and down arrows for the speed.



    Searching on Craigslist usually turns up one or two a week .. Here is the last one I found.
    Take note of the slider for speed.



    After getting it home .. all you have to do is take off the motor cover. Everything we are interested
    in is below that cover. Pull everything out of there and you can toss the rest. Note: the transformer
    thingy is a choke .. it helps keep the motor from humming .. but ... I rarely use it. But grab it
    just in case.



    continued in next post.
    John Titor, when are you.

  • #2
    As an aside, often the motor has a direction on it in the way CW or CCW, this is predominantly because it has a threaded on flywheel which could come unscrewed in the reverse direction, for most applications remove the flywheel and run in either direction.
    The controller shown looks like the popular MC series, the early versions were SCR bridge types, the later models were the little better PWM controlled.
    Max.

    Comment


    • #3
      The motor has a red and black wire that are the main power feed wires. Sometimes there are a couple extra and
      these are usually to a thermal protector .. Usually you can just pull that right out.



      Ok .. lets check out the controller ... my favorite part.

      l analog controllers have the same inputs

      YELLOW CIRCLE .. shows where the power (AC) is hooked up to. Usually labeled L1 & L2 or AC1 & AC2
      RED CIRCLE ........ shows where the motor hooks up. Usually labeled M+ & M-
      WHITE CIRCLE .... shows where the potentiometer hooks up. the middle contact obviously goes to the middle
      contact and the others just hook up. it will be obvious when you start it up ... if you have it
      wrong the motor will speed up as you turn the pot down. lol ..




      So put everything up on your bench. The first pic is the complete setup. Thats it .. Thats all you need.
      The second pic ... just plugged everything in and its all ready to go.

      Last edited by Mike Amick; 01-22-2017, 03:15 PM.
      John Titor, when are you.

      Comment


      • #4
        nice! that looks like a motor I've used before and the controller is an MC60/65 from the looks of it - they're really nice. I use the chokes in my builds - I found that the hum was almost eliminated and the speed maintenance a little tighter/ smoother with them.

        Couple of the additions to the Mike's posts:

        1 - fwd/rev motor direction - put a DPDT switch with center off on the DC wires going to the motor and you can reverse motor direction easily. Plenty of diagrams out there, but in essence the DC wires from the controllers go to the center posts, the wires to the motor attach to one side and are connected in a crossover fashion to the other side. Works really well - I use mine on the DP for power tapping and on the lathe for metric threading.

        2 - start at previous speed - on all the treadmill controllers I've seen, you have to turn the pot to off and then back up to get the motor to turn. You can sidestep this with the fwd/rev switch as above, although you still have to reset the board everytime you switch the machine back on (what I have on my DP with MC40 board). Or, you can disconnect a resistor on MC60 boards (the one right next to the center pot post, labelled RPS3/ R19 in Mike's pic) and then it will always start at the same speed, even from off.

        I've got around the LH flywheel issue in a couple of ways. One with a key and bolt/ washer in the end of the shaft (lathe), another using a flat ground on the shaft and a set screw. If you know that you'll never reverse the motor (eg. a grinder or saw), you can just orient the motor so that it's turning the right way not to unscrew.

        Comment


        • #5
          Good post thankyou!

          Comment


          • #6
            forgot to say, there's a relatively straightforward way to provide a PWM signal to those digital controllers, like the MC2100 I have in the treadmill outside

            https://sonsofinvention.wordpress.co...eter/#more-389

            I think this version is a bit more complicated than most of us would need, but it looks achievable. A simple 555 timer would probably work, I've seen versions of those too. I'll be taking the arduino route when I get round to doing my grinder.

            Comment


            • #7
              I agree it looks like a MC-60 if so it should just need a 5k pot.
              There are a few reverse-engineered schematics out there some not quite accurate, but close.
              I am just doing a reverse engineered version as time permits.
              The one down side that many complain about is the built in automatic acceleration and coast down, which would be nice to eliminate without the use of the flywheel.
              Max.

              Comment


              • #8
                Originally posted by mattthemuppet View Post
                2 - start at previous speed - on all the treadmill controllers I've seen, you have to turn the pot to off and then back up to get the motor to turn. You can sidestep this with the fwd/rev switch as above, although you still have to reset the board everytime you switch the machine back on (what I have on my DP with MC40 board). Or, you can disconnect a resistor on MC60 boards (the one right next to the center pot post, labelled RPS3/ R19 in Mike's pic) and then it will always start at the same speed, even from off.
                Hey Matt ... isnt that the coolest thing ? That problem has been around for ever and just the other day
                someone on here (maybe you) reported they had found that and sure enough, I ran out to the shop and
                tried it and it works like a champ. That REAAAALLLY makes these boards more useful.

                Also .. thanks for the 2100 pulse provider .. haven't seen that one. The ones I have seen, according to the
                authors .. it wasn't so cut and dry .. they had to play around quite a bit to get things working.

                And thanks for the comment. I purposely made my post as dead simple as possible. Kind of a starting point
                to get someone started.
                John Titor, when are you.

                Comment


                • #9
                  Max - I actually like the flywheel on there - simplifies cooling and also deals better with interrupted cuts and other variations in load. Coast down does take a while though - with threading to a shoulder on the lathe I have to slack the countershaft off, otherwise I can crash into the shoulder. Same deal with power tapping on the DP, only through holes and I have to switch the motor off some distance before the tap has finished cutting. Bit of a pain, but not enough to do without the flywheel.

                  Mike - yeah, I think that was me a while back I found it on some other random site while looking for different TM motor set-ups. Sadly only works with the MC60/65, I tried with my MC40 and it didn't have any effect.

                  The arduino set up is still a little challenging, but I think it would be worth it for higher HP TM motor installs - the MC2100 board that is on the treadmill is presumably rated for the 2 1/2hp motor on there, whereas the old analog MC boards usually came with 1 to 1 1/2hp motors and I've read of people burning them up with larger motors. I know that the KB drives come with a HP specific resistor and a max current, based on cooling, so there may be something too that.

                  short of a 3ph motor and VFD, I think this is about the best thing you can do to a lathe/ mill/ grinder/ bandsaw.

                  Comment


                  • #10
                    Everyone to their choice but I don't know of a CNC spindle that has a flywheel.
                    I would have thought it increased the motor temp due to the torque required to get it up to speed and energy expended on the slow down.
                    I would be worried about it coming off if doing a reverse.
                    Max.

                    Comment


                    • #11
                      Hey .. you other Treadmill guys .. just dragged this one home, first one of these I have seen.

                      It has shocks which work really well, and the motor is at the other end of the TM.

                      .. mc-2100 in it.

                      John Titor, when are you.

                      Comment


                      • #12
                        I tried running one of the treadmill motors in reverse. It caught fire! I suspect the brushes were leading or lagging the magnets and when reversed they arced a lot. Also the axial flow cooling fan no longer works.

                        However, I managed to find a Baldor tread mill motor on Ebay! It is marked as reversable, and has a centrifugal fan that works in either direction. REALLY well built compared to the others!

                        Comment


                        • #13
                          whoa .. before we start an urban legend here .. I just want to say, I have never had a problem with
                          running a TM motor in either direction other than the screwed on flywheel issue.

                          You are probably right about the brushes having some funcky trailing edge on them.
                          John Titor, when are you.

                          Comment


                          • #14
                            The TM motor I have makes terrible noises when run in reverse. Squeaked and squalled, which seems to have been the brushes. Which is annoying, as my application WAS for reversing.... I could not use it.
                            CNC machines only go through the motions

                            Comment


                            • #15
                              I wouldn't have let it get away with that .. grin.

                              I would have set it off to the side running in reverse .. and go about my work, listening for
                              changes.

                              Wouldn't have hurt anything .. and I'm sure you have fire extinguishers ..
                              John Titor, when are you.

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