Motor for machine

Hello

Has anyone or do anyone run a Treadmill Motor on their machines.

from what I have read , these motors have good ajustable speed/power control with no loss of torque,

Are they easily converted for say powering a milling machine?

they have plenty on ebay for around the £70 mark

Thanks

lee

They all seem to be 180-230v DC motors

1.5 HP CONT. DUTY

180V DC Max

4200rpm

5 AMPS

CLOCKWISE ROTATION

All the 180v means is that the full 240v mains shouldn't be applied to them. ie ran at a bit lower speed via pulses so the mean value of the voltage is correct. As far as I'm aware they are brushed universal motors or brushed permanent magnet - probably some what over rated on the motor plate. If you search youtube you will find people running them on ac and dc. I'm not sure if perm magnet motors can be run on ac so there is probably 2 types about.

People have done this on lathes but I have no info on how well it has worked out. Brushes don't generally like being run in different directions but if the commutator is cleaned up with pcb eraser as washing machine people do and new brushes fitted it stands a better chance of being ok if the direction has to be reversed but the brushes themselves might be positioned to suit the direction the motor usually turns.

Buying treadmills with problems of one sort and another, breaking and selling the bits seems to be a bit of a popular occupation.

Actually I'm pretty sure I came across a web page where some one had used one on a drill. A search might bring the pages up.

John

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Edited By John W1 on 09/07/2015 15:46:45

Easily found again

**LINK**

As usual though - no usability info.

To be honest having worked on electric vehicles that use this sort of DC voltage I am surprised they use DC at all. It's more dangerous than AC.

It's a little more complicated really but the torque characteristic comes from say 10 amps continuous at some flat out speed at 180v average. If the motor was run at 1/2 speed the average voltage would be dropped ot 90v by driving it with a 50% on 50% off waveform. The current limit flat out is due to resistive heating but as the motor is being driven with a 50/50 waveform the current peaks can be 20 amps for the same heating effects so power remains the same. There are complication though.

Actually I should know about permanent magnet motors and AC as I have a couple of 180v motors that came out of sheep shearers that I think are permanent magnet but having looked at the waveform maybe 20 years ago sorry I can't remember. Maybe some one else knows. A simple triac speed controller would do the job if they do.

John

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Edited By John W1 on 09/07/2015 16:48:56

Hi Lee

"Has anyone or do anyone run a Treadmill Motor on their machines.

from what I have read , these motors have good ajustable speed/power control with no loss of torque,

Are they easily converted for say powering a milling machine?"

Short answer YES

Lathe, Mill, Hacksaw, 2 Drill Presses all on DC motors using KB Electronics, Minarik, and Dart Controllers

That use 230 volts AC converted to 180 volts DC.

You need to know and understand how to wire them up and set them up to match the motor power.

Mistakes can be FATAL and permanent DEATH can be the consequences.

They can give excellent speed and torque control at high speeds say over 1/2 the motor RPM this falls off the available torque at low speeds.

A separate cooling fan ex computer 12 volt DC is desirable when using less than full motor speed.

I use an AMP Meter wired in on the DC motor leads For setting up and measuring the load when machining.

As for the reversing If the brushes on the motor are at 90 degrees to the commutator then no problem with running in clock or anti-clock as with a lathe or mill almost all running will be in one direction.

Download the manual from KB Electronics and or Minarik

http://www.kbelectronics.com/Variable_Speed_DC_Drives.html

Or

http://store.minarik.com/product/drives/minarik-drives/MM23001C

Hope this helps

Eric

Thanks for the the information, and links, I will be looking into this abit deeper, seems like the best way is to buy the whole treadmill with the controller

thanks

lee

That is probably both safer and cheaper as it's then possible to see what rev ranges could be used from the treadmill speed working backwards. Many of the motors come with a fan built in.

They appear to use Chinese HP - what goes in rather than what power comes out of the spindle. I suspect they do that on some of the lathes.

If you fit a current monitor it would be best to use an analogue one as that will read average current - not far from the true rms value. Digital RMS meters generally have a very restrictive frequency range. As there are now cheap semiconductor current sensors about one may be built into the controller in the treadmill. They look like the ones shown in this link

**LINK**

I've wondered about them but say 1/2 speed is the slowest that they can be run. That means the speed range will be circa 2 to 4k rpm. On many machines that will mean a lot of speed reduction will be needed. Similar technology has been used on the cheaper mills and lathes for some time - probably why they use a noisy gear for low speed.

It also looks like some treadmills don't use permanent magnet motors. I've seen comments that they can be using series wound motors but as I have never looked at one pass. The series ones will run on AC also shunt wound if some use that. These could be controlled with a normal triac based speed controller or run on DC.

John

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I wouldn't bother with it. For a start 180 V at 5 A, assuming 90% efficiency, gives only just over 1 hp not 1.5 hp. Then, by the time you have bought a dc controller, you will end up spending nearly as much as you would on a new 3 phase 1.5 hp motor and inverter drive and you would only have something that may or may not do the job well. Your choice!

Russell.

The trick with tread mill motors is to get the whole tread mill, maybe worn out, but that way you get the speed controller, also the speed indicator(don't know if that's any use), two rollers, and some useful scrap metal, the one I got had a big bit of plywood on the deck that now forms the tray on a trailer I have for my bicycle. A friend uses the motor to drive a water pump.

Ian S C