Treadmill motor how to

[sb327]

It was mentioned in another thread about how to make a treadmill motor work for use on a lathe. I have used several over the years, my first one about 9 years ago on my Bridgeport milling machine. It’s still running just fine. I have one on my drill press and one on my 2”x72” belt sander.

They are permanent magnet dc motors which require a controller. Fortunately the controller from the treadmill can be used as well. You just have to know how to ‘control’ the controller. They are advertised anywhere from 1.5 hp to as high as 2.25 hp. In reality, they are comparable to a 1 hp motor. Which isn’t bad considering they are smaller and can reach ridiculous rpm’s and have more torque at low rpm’s with the controller sensing load and adjusting as needed (to an extent).

So as I get a chance I’ll be discussing this. If this has already been discussed here before, someone let me know.

Gotta eat supper now.

Dave

[Mole2017]

I'm interested to hear about it.

[Nvreloader]

SB327

I'll be following along as I just lost my motor in the med drill press,6 spds.
I just happen to have an old treadmill getting ready for a dump run..........

Thanks,
Don

[PeterC]

Google KBIC controllers. I used one on a tread mill motor before and they work well.

[PeterC]

Look for a KBIC motor controller. I have used them with tread mill motors and they are well built.

[RBQChicken]

Following.

[Firewalker]

I made a 2X72" belt grinder with an old treadmill motor and controller. Lots of power, infinitely adjustable and very quiet.

There are people making good bolt on adapters for lathes, drill presses, grinders etc on Etsy.

[YEMX]

Following...  I've got a 7x lathe project to finish up! 

[sb327]

Google KBIC controllers. I used one on a tread mill motor before and they work well.

They do work just fine. I know others who have used them with good success. This thread however is for the guys like me who just can’t stand to throw something good away. And like to tinker

Ok, here we go. The motors and controllers I’ll be talking about can be found in the ‘home’ models. Commercial models are a lot bigger and have a different controller.

The motors are basically all the same. The mounting style will be the only difference. They come with a micro-groove type pully/flywheel/fan. To remove it, grab the motor shaft on opposite end with vice grips (the end is rebated for this). They are LEFT HAND THREADED. You can generally just unscrew it with some force. If not, give the vice grips a sharp whack. Remember, LEFT HAND THREADS.

The shaft is 17mm, which is common to Chevy/Ford alternators. So if your a real scrounger, like me, you can use the spacer, fan and pulley from one. I just cut the ‘nut’ part from the flywheel when doing this. It generally put a grub/set screw in as well because these shafts are not keyed.

Dave

[sb327]

Now the controllers.

There are basically two types. SCR and PWM.

MC-60 or variant are SCR
MC-2100 or variant are PWM

We’ll start with the MC-60. It is smaller and simple. Older technology but very robust. Easy to control. It will have a ‘choke’ (looks like a transformer) between the controller and motor. It just helps smooth out the power. Not necessarily needed if room is tight. Your call on that.

Controlling is done with a 10k pot. Cheap. The board is labeled well (usually). You will find three terminals labeled H-W-L or red white black

H-red- high (12v power/signal)
W-white-wiper (variable with the wiper/center of pot)
L- black-low (0v power/signal)

Simple. The other terminals you will use are the AC in. Line/neutral.

The motor red/black. A+ and A-  (can be reversed depending on rotation needs.

Two blue wires from motor. These go to a thermal switch in the motor and cut power to the board in case motor overheats. They plug into board close to the ac inputs.

This board is a safe start board (like most variable speed hobby lathes/mills). Meaning it will not start in the event power to board is interrupted.

Picture of my MC-60 on my bport milling machine. I am holding a pot next to the terminals how it would be wired. My pot is mounted elsewhere.

Dave

[sb327]

Now the 2100. This one eluded me a while. I have since found a simple way to control it. You will need a PWM signal generator. Cheap on amazon (<$15). They come in all shapes but do the same thing.

The board needs to see a signal that is 20hz frequency with a variable duty cycle. The frequency verifies a ‘good’ signal and the duty cycle (0-100%) controls the speed.

Wiring is simple however. Save the old control plug and wire. You will use the black red and blue. Blue is the pwm signal and red/black are power.

The frequency generator will have corresponding connections.

Red + (10-12v)
Black - (0v)-  the black and black/white stripe are same and can be connected together
Blue pwm signal

To run it, set duty to 0%, set frequency to 20hz. Adjust duty up to desired speed.

To stop (while using), set freq to something different than 20. To restart at same speed, set freq back to 20. The board ‘ramps up’ the speed. You can also just install an interrupt switch on the signal wire for ‘in use’ stop/start.

Like the 60, the 2100 will not restart automatically after power interrupt to board. It has to receive a ‘non’ good signal and then a good one to restart. Safety

Here are a couple different boards/signal generators in the ‘2100’ class. Note that one is a MC-1650, it controls the same. It doesn’t have the thermal switch tabs on the board, they were in-line with ac hot wire.

Note that some boards will have incline control built in. Ignore that part   

Also, I didn’t mention, but you need a main switch on ac line coming in.

Dave

[sb327]

I am certain I have missed quite a bit so feel free to ask questions.

Which one of the controllers is better, you ask?

They both are fine for our uses. The 2100 does offer a little ‘smoother’ power. It sends full voltage to the motor at a variable duty cycle. Meaning it is ON for a certain % of time vs it’s OFF % of time. This is done at an extremely high frequency (many thousand times per second) through a mosfet. The 2100 also provides a better speed control under load.

But the 60 is a tough board and is very simple.

Dave

[HunterWhite]

David, thanks for your work, and for posting the information.

I wish that I had found a thread like this a couple of years ago.
I discarded a precor 905e because it would stop for no apparent reason.
I think that the motor was 90VDC. I couldn't find any information about the controller.

If you are going to re-purpose the motor and controller, don't forget to re-purpose the conveyor belt as a backstop behind your pellet trap!

Hunter

[bavaria55n]

Great idea, and you can still keep the frame to hang clothes on.
A win win!
Gary

[sb327]

And the roller pipes, bearings and shafts are handy. Most have a pretty decent running board that can be re-used as well. It’s pretty stout for particle board.

I did forget to mention, some of these have a speed sensor on the belt driven pulley. It is only for the machine display to tell how fast you are running/walking. It does not provide feedback for the motor controller. I discard it but it could be used as a tach sensor.

Dave

[superchikn]

Following

[mosparky]

Just the article I wanted to see. I built a 2x72 belt grinder years ago but when it came time to buy a VFD to run it, times got hard and it just sits. Now the wife wants to de-clutter and the treadmill is slated to go.
Question ... Does the MC-60 board have a power supply built in or do I need to salvage something else ?? I ask because I can't recognize a transformer on the board from that angle. Unless that thing marked 5W5... is one in a pkg I've never encountered before.

[sb327]

The mc-60 is the power supply. The ac power is converted to dc through the board via scr technology.

There may be a coil/choke wired between the mc-60 board and the motor but that is for smoothing the dc power going to the motor.

Dave

[mosparky]

Thanks for responding to such an old thread. I can find a great many uses for a variable speed DC motor set up. My grinder for one, maybe even slow down a wood cutting band saw for metal cutting as well as converting some 3 phase machines for home use. I can see myself scooping up unwanted treadmills for spare parts in the near future.

[sb327]

They are extremely handy. I currently use them on my

Milling machine
Drill press (no belt changing for speed)
Belt sander
Metal bandsaw (homemade)
Hydraulic swage press

Let me know if you have more questions,
Dave