Help With A Treadmill Motor Controller

[mattrgs]

Hi all

I have acquired a treadmill, and taken it all apart, and I want to be able to control the speed of the motor using a potentiometer, rather then using the control panel. From this I am then hoping to put it to use in a machine.

I have a basic understanding of electronics, but I was slightly stumped when my controller used an Ethernet cable to the panel rather than a few wires.

I have attached a labelled photo of the controller, and hopefully someone can point out where about I need to put the potentiometer.

The treadmill was a J6F Tunturi treadmill, with a 130VDC motor. From prior research it appears it is likely to be controlled by PWM, but I am not sure.

Thanks for any help!

 

[jim18655]

Any terminals, other than the motor connections, on the board? Is the speed control a pot or push buttons? If a speed pot, open the control panel and see if the speed pot is connected to the board or directly into the ethernet cable. I'm going to guess you might need the panel to do the interface but you should be able to move the speed pot remote from the panel.

 

[intjonmiller]

From my observations (a couple treadmills I've disassembled and many I've seen in posts like this) there are very few treadmills that allow such simple adaptations of the existing control board. My current project is temporarily wired up with just a bridge rectifier ($2-3 part) for full speed, and I'll be replacing it with a budget (non-load compensating, for instance) PWM controller. I've yet to settle on one, but there are many out there in the $10-50 range that are at least theoretically sufficient for these motors and my needs.

Otherwise there's the option of rigging up the entire treadmill control panel and using the buttons to control speed, with a chart to convert its MPH/KPH figure into RPMs or SFPMs, depending on your application. Ugly and bulky, but cheap and perfectly effective.

 

[brino]

Hi mattgrs!

First, welcome to the site!

I suspect you are dealing with the same thing many of us are....see here:
http://www.hobby-machinist.com/threads/dc-motor-drive-basic-questions.46731/

I am not sure it is ethernet, it could be but that might add a little more complexity than required.
I suspect they use RS-232 or RS422 type signalling, though anything is possible with the low price of small miro-controllers.

I still need to look into mine (referenced in that other post), but hope that I can find a signal on the motor control board that has a voltage varying with the speed dialed up on the LED/pushbutton control/display board. Then I could simply control that voltage with a pot and get rid of the control/display board completely.

-brino

 

[intjonmiller]

My assumption was that it uses ethernet cable and connectors (8P8C), not that it was using an ethernet communication protocol.

 

[John Hasler]

Otherwise there's the option of rigging up the entire treadmill control panel and using the buttons to control speed, with a chart to convert its MPH/KPH figure into RPMs or SFPMs, depending on your application.

Or reverse engineering the board and programming an Arduino (or perhaps just a handful of ICs) to replace the computer in the control panel.

 

[intjonmiller]

If Matt's "basic understanding of electronics" is similar to mine, then he is aware that such a solution is possible, and that's the full extent on that one.

I have a brother who has been doing such solutions since he was in high school. He wired and programmed everything. But now that he's an IT director for a local manufacturer he never has time for such fun things. (Or the 12" Logan lathe gathering dust in his garage...)

 

[kvt]

Is there a number on the controller or on one of thestickers, LIke mine is a MC2100-12 and I is a pain. It also has the wire that looks like an Ethernet cable the end is wired like one but it is not using anything close to the Ether signaling. I am getting a MC60 and using it. along with some other ports to control and give me speed control no my motor. Also a lot of the motors always reset to zero when you turn them off, THus you hae to bring them back up to speed by turning the speed all the way down and back up to get them going. I do not know much electronics but have learned a few things in the last few weeks on treadmills and some of the controllers I also found that a lot of the stuff out there is not designed to give you a much VDC as these motors take/can take. Keep us informed.

 

[mattrgs]

Hi, thanks for all the responses. You may be correct that it is not Ethernet, that is what it looked like. The control panel all of the buttons, but is overly complicated for just speed and brings up errors as the incline motor isn't attached. I had read on some websites (now can't remember which ) that the PWM could be controlled with a pot, but this may only be the case for a few controllers.
My understanding was that there was a small voltage sent from the control panel to the motor control bit that altered the PWM with the change in voltage. Therefore a potentiometer could easily control this voltage.

Thanks again

 

[John Hasler]

I suspect they use RS-232 or RS422 type signalling, though anything is possible with the low price of small miro-controllers.

If they use any standard protocol at all it is most likely SPI. It is also possible that the computer in the front panel simply sends a PWM pulse train down the cable to the power board.