Any way to add a speed controller to a treadmill motor?

[RhondaHonda]

I have a lightly used Proform treadmill that I let the smoke out of the motor controller and am reluctant to spend $200+ on a replacement part with minimal warranty. I tested the motor with a cordless drill battery and it still spins. Is there a simple way to hook up something like a dimmer to control speed and bypass the entire control panel? I would only use it for walking, say 3.5-4.0 mph and could just get the speed set and jump on and walk.

 

[skyactiv]

It can be done, but you really should know what your doing. You can learn however.

 

[samven]

If you tested it with a battery its a DC motor so the control board probably used pulse width modulation (PWM). These are relatively simple to build but you need to make sure the components can handle the current. Just lowering the voltage is not a good solution as the motor will try and make up the wattage loss by drawing more current and burn up the windings. You might want to find someone with a bit of troubleshooting knowledge and se if they can fix the board. Sometimes there is a fuse on the power supply or the output stage that blows. They are not always what you expect as some of them (pico fuses) look like a resistor soldered to the board.

 

[AandPDan]

Maybe check out speed controllers for R/C airplanes or cars. Some of them can handle quite a bit of current and are for DC.

 

[ctechbob]

Do a search on Ebay, there's tons of DC speed controllers up there

. First one on the search I just did is a 15 amp model that comes with the knob. $10. Worst case, you're out $10. You will need to find the power source in the treadmill though or provide an external source. Also be worth looking up the specs on the motor to see what voltage it is rated for to give you an idea of what range of voltages you'll need to supply.

 

[Dave9]

I don't understand. Repair what failed on the existing motor controller.

How did you let the smoke out? It may need some engineering rework, maybe a 20 cent more expensive (transistor?) or heatsinking to it improved or XYZ, but odds are that the path of least resistance is repair and improve what you have instead of reinventing the wheel.

If you really want to downgrade the functionality, since you have tested that it works with a DC low voltage source, then you need to determine a (rough) estimate of what voltage it needs, then proceed from there with a DC motor speed controller.

If the entire board or whatever you are comfortable with using is trashed, then you will need to build or buy a circuit to adapt the AC input to the DC level your chosen controller accepts. There are many variables, multiple ways to get to a result that is just a certain speed for walking.

If you want the simplest solution, it would be to estimate what % of the speed you need is achieved by the particular battery voltage you used, then you determine the target voltage for the target speed. Then you use ohm's law to determine current but better to overshoot that, since voltage determines current in this resistive load application. Once you find your target voltage and minimum current, it is easy enough to buy a SMPS to meet that, but as above I would rather fix the fault and have it fully functional again but improved so that the chances of same failure happening again are reduced.

 

[Wolf359]

Did you try searching all over for the controller? I found one on eBay for my treadmill and it wasn't that much money. The part number was right on the controller. You could also just do a google search for it, sometimes the cheapest place isn't eBay. A quick swap and I was back in business.

 

[RhondaHonda]

I was running on it when it quit working. The control panel powers up but the belt won’t move. I did some internet diagnostics and it’s pretty common for the motor controller to be the faulty part. I contacted a company that exchanges your board for a refurb one but he didn’t have my part and wouldn’t repair mine. A treadmill parts place was cheapest but still $200. The part from Pro-form was $250ish. I’ll do some more research. My abilities to diagnose and repair the board myself are limited but I’m open to learning.

 

[RhondaHonda]

Here is the tag off the motor. Any idea what specs I’d need on the speed controller?

 

[ctechbob]

That seems like those specs are out in space. 21 amps @130v? That's a lot of power. Bare minimum you'll need something rated at 25 amps I guess if those ratings on the motor are realistic.

 

[Wolf359]

That seems like those specs are out in space. 21 amps @130v? That's a lot of power. Bare minimum you'll need something rated at 25 amps I guess if those ratings on the motor are realistic.

Naw, that's the max rating. No one uses a treadmill like that anyway, max speed is probably 10-12 mph. That 12mph would make you a 5 minute miler. The only time you see a lot of 5 minute milers is at a race where a bunch of people will line up at the 5 minute mile pace, but then there's only a few that actually finish at that pace.

 

[ctechbob]

Naw, that's the max rating. No one uses a treadmill like that anyway, max speed is probably 10-12 mph. That 12mph would make you a 5 minute miler. The only time you see a lot of 5 minute milers is at a race where a bunch of people will like up at the 5 minute mile pace, but then there's only a few that actually finish at that pace.

I realize that, but if they designed the treadmill to work at all near those limits, you'll have to as well. If you use something like a 5A controller on it because you're only ever going to go that fast, you'll overload and burn the controller up in short order. You never want to be constantly operating something like that near its maximum.

Personally I think that motor rating is out in space somewhere. Doesn't seem at all reasonable for that size/voltage.

 

[RhondaHonda]

I’m certainly not a 5 minute miler. I can sprint at 12 mph (treadmill max speed) for maybe a minute or so but this thing isn’t going to see that kid of duty. I think there’s a wiring diagram taped to the case, I’ll look at it tomorrow for any specs.

 

[JT20]

I have a lightly used Proform treadmill that I let the smoke out of the motor controller and am reluctant to spend $200+ on a replacement part with minimal warranty. I tested the motor with a cordless drill battery and it still spins. Is there a simple way to hook up something like a dimmer to control speed and bypass the entire control panel? I would only use it for walking, say 3.5-4.0 mph and could just get the speed set and jump on and walk.

Why don't you have a Honda as your Avatar photo, lol?

 

[RhondaHonda]

Why don't you have a Honda as your Avatar photo, lol?

I don’t think I have a digital image of that POS that I owned when I created my account! In all actuality it was a great buy for $50 and served me well as a beater during and after college.

 

[JT20]

I don’t think I have a digital image of that POS that I owned when I created my account! In all actuality it was a great buy for $50 and served me well as a beater during and after college.

Hey, awesome lol. Sorry for being OT I just saw your avatar and I was like, "That's not a Honda lol." My Honda was a beater too.. it is now gone. It may have been okay but got about half of its life it was maybe okay and trouble-free-ish and for half of its life it wasn't worth it, even though I wanted it to be.

Very low to the ground, too. High theft rate, IMHO. But still. All good.