How can I get this treadmill controller running?

[Azalin]

I just tried. It cause a short circuit, bloving the fuse.

 

[cowboybob]

Since I have no idea how you hooked up the pot, I'll go on the assumption that you inadvertently applied too much bias to the gate of the IGBT. Was the motor also hooked to the PCB connections? If not, it should have been:

I forgot to ask what is the resistance (in ohms) of your potentiometer? That value might be stamped on the metal case. If not, check it with the Ohmmeter (Ω symbol) of your VOM (or DVM) with the pot NOT connected to the PCB circuit. Connect per pic below:

Ultimately, the idea here Suat (missed your name in your #1 post ) is to apply, very slowly, a gradually increasing test voltage (bias) to the gate of the IGBT, thereby gradually increasing the voltage/current going to the motor.

Too much bias, too soon, will cause a excessive current surge through the motor that will, most likely, blow the fuse.

 

[Azalin]

Hi Bob,

I did it exactly as you said. The pot I tried is 5k OHM. Motor wasn't connected.

You know there is a trafo on the board. I think it is there to lower the voltage and feed the console. Maybe I should desolder that trafo and throw it so maybe any interference causing to short would be eliminated?

 

[cowboybob]

Hey Suat,

I think the best thing to do at this point is return everything to the point where it was working correctly, i.e., console hooked, motor hooked, IGBT properly attached to the PCB, etc.. Let's make sure nothing is "toasted".

Then we'll try again. I'll put together a step by step list for you of checks for first (like normal operating voltages) then we'll proceed to how we can emulate the signal from the console with the pot.

I'm the sort of technician that prefers a methodical set of steps, taken one at a time, so that I don't make things worse... .

Thanks for your patience.

 

[spec]

Hi Azalin and cowboybob,

I don't like to intrude, but there is something I don't understand:

In the original treadmill circuit the motor presumably was driven by pulse width modulation (PWM) which would mean that the IGBT would have low dissipation at all motor speeds/loading. But it is being proposed, if I follow this thread correctly, that the IGBT be controlled by a DC voltage on its gate, which would mean linear control. So wouldn't the IGBT overheat- am I missing something.

spec

 

[MikeMl]

Some treadmill motor-controllers use AC phase-control (like a incandescent lamp dimmer), where the control element is a varying resistance, but implements a motor speed control using back-emf of the motor. The one I bought for $5 does. It has a large iron/copper inductor in-series with the motor to smooth the current pulses to minimize noise and vibration at low motor speeds.

I got a schematic on the web of the motor-controller as used in the one I have. Those controllers can be bought inexpensively on Flea-bay. This controller is the one a lot of machinists use to adapt treadmill motors to lathe spindles, etc.

Write back if you want the schematic (not on this computer), and a picture of what this particular controller looks like...

 

[spec]

Some treadmill motor-controllers use AC phase-control (like a incandescent lamp dimmer), where the control element is a varying resistance, but implements a motor speed control using back-emf of the motor. The one I bought for $5 does. It has a large iron/copper inductor in-series with the motor to smooth the current pulses to minimize noise and vibration at low motor speeds.

I got a schematic on the web of the motor-controller as used in the one I have. Those controllers can be bought inexpensively on Flea-bay. This controller is the one a lot of machinists use to adapt treadmill motors to lathe spindles, etc.

Write back if you want the schematic (not on this computer), and a picture of what this particular controller looks like...

Thanks Mike- Yes, if you wouldn't mind and the OP doesn't mind, I would like to learn some more about the $5 controller. I think it may be relevant to this thread too.

spec

 

[cowboybob]

Hi Azalin and cowboybob,

I don't like to intrude, but there is something I don't understand:

In the original treadmill circuit the motor presumably was driven by pulse width modulation (PWM) which would mean that the IGBT would have low dissipation at all motor speeds/loading. But it is being proposed, if I follow this thread correctly, that the IGBT be controlled by a DC voltage on its gate, which would mean linear control. So wouldn't the IGBT overheat- am I missing something.

spec

Hey spec,

This particular one looks like a PWM system, although can't find a schematic, so no way to tell for sure. And you're right in that current would be steady and over heating would be a problem.

But you bring up an interesting thought.

How about leave the console attached? Take the whole rig (PCB - without its current facade - and motor) re-mount it all and mate it to the lathe, I guess. Then you'd have a control panel with at least some manner of readout to convert to spindle speed. I kind of like that idea .

 

[spec]

Hey spec,

This particular one looks like a PWM system, although can't find a schematic, so no way to tell for sure. And you're right in that current would be steady and over heating would be a problem.

But you bring up an interesting thought.

How about leave the console attached? Take the whole rig (PCB - without its current facade - and motor) re-mount it all and mate it to the lathe, I guess. Then you'd have a control panel with at least some manner of readout to convert to spindle speed. I kind of like that idea .

Yes, that sounds good and it mainly involves mechanical modifications rather than disturbing the electronics.

I am very interested in this thread as one of theses motors will provide a low cost and simple way to power machinery. In the UK there are quite a few metal working lathes available where the motor/drive is faulty. In fact, about six months ago I could have had one for nothing had I have moved a bit faster. A lathe is like a multimeter and scope- every chap should have one.

spec

 

[cowboybob]

... A lathe is like a multimeter and scope- every chap should have one. ...

Agreed. I've got a welder (stick), grinders, drill press,etc, but no lathe . And I had no idea the old treadmill guts went for so cheap!

 

[Azalin]

Some treadmill motor-controllers use AC phase-control (like a incandescent lamp dimmer), where the control element is a varying resistance, but implements a motor speed control using back-emf of the motor. The one I bought for $5 does. It has a large iron/copper inductor in-series with the motor to smooth the current pulses to minimize noise and vibration at low motor speeds.

I got a schematic on the web of the motor-controller as used in the one I have. Those controllers can be bought inexpensively on Flea-bay. This controller is the one a lot of machinists use to adapt treadmill motors to lathe spindles, etc.

Write back if you want the schematic (not on this computer), and a picture of what this particular controller looks like...

Yes Mike please share. I'm open to any idea/help.

 

[Les Jones]

As MikeML says some speed controllers used to control permanent magnet DC motors use phase control. Some people have used treadmill motors and controller board to replace failed motors on their lathes and milling machines. When the motor failed on my Seig x3 milling machine I expected that it would have also damaged the controller. (It had not.) I reverse engineered it and have put the schematic on this page of my website. Moderators. I'm not sure if it is against the rules linking to my own website. If it is please delete this post.

Les

 

[Azalin]

Thanks Les.

I'm afraid this is far more complicated for me to build. It would be very nice if I could get the one I have running without a treadmill console. I did read a lot that most people use 555 timer circuit to control the controller but I'm too old (I'm 40 )to learn electronics 101 just to get the controller running. I have a cheap 555 circuit tho. Tested it on the controller by wiring the positive pole to the IGBT gate. It resulted the same as the 10k ohm pot failure. I don't know what I'm doing wrong.

I tried to use the controller with the console on my lathe but it's a real pain. When I reverse the direction of the motor with a switch and a pair of contactors the console goes into error mode. The only way to get the motor running after switching the direction is to push the stop button and then push the start button on the console.

 

[cowboybob]

I tried to use the controller with the console on my lathe but it's a real pain. When I reverse the direction of the motor with a switch and a pair of contactors the console goes into error mode. The only way to get the motor running after switching the direction is to push the stop button and then push the start button on the console.

Well, at least some progress!

Just wondering, Suat, what this:

connection is doing, i.e., is it possibly a reverse direction sensor signal. I'm wondering if you temporarily disconnected just that one wire (looks orange or tan) if that would allow you to reverse the motor (as you described above) and not have to reset the controller.

 

[spec]

When I reverse the direction of the motor with a switch and a pair of contactors the console goes into error mode. The only way to get the motor running after switching the direction is to push the stop button and then push the start button on the console.

Just one observation, for what it is worth. A motor can be damaged by reversing the drive while the motor is still spinning. So you need some form of protection for this condition.

spec

 

[Azalin]

Hi Bob,

I thought that "REV" stands for "revolution" or "start motor revving" command. I don't think that controller has the reversing ability after all. I tried to trick the controller by connecting the 13v output to the REV but no luck.

I feel it is all about triggering the relay on the controller because when I press the "Start" button on the console I hear the relay clicks and motor starts to revving. So, is it possible to solder a pair of wires to the relay and control it externally? The relay is very simple with 5 pins.

I don't know if this is a stupid idea.

 

[Azalin]

Just one observation, for what it is worth. A motor can be damaged by reversing the drive while the motor is still spinning. So you need some form of protection for this condition.

spec

Hi Spec,

My solution to this is to always wait the motor stop then switch reverse.

 

[MikeMl]

The treadmill I got had a MC80 controller. I posted a request for schematics on another forum, and MaxHeadRoom78 provided me with the attached MC60 schematics, which appear very close to what is in the MC80. I also attached my notes and some pictures of the motor and controller.

Here is a link that basically shows what I ended up doing:

MC60/80 replacement boards are all over the web, and are cited on a lot of machinist's websites.

 

[cowboybob]

Hey Suat.

I thought that "REV" stands for "revolution" or "start motor revving" command.

I expect you're right.

Have you been able to return it to the original state, or are you too far along to do that?

 

[Azalin]

Yes Bob. Its like new now.