# how to control a treadmill motor



## karlw144

I've used treadmill motors to run a mill and lathe (motors/controller/wires/etc) removed from a functional treadmill and I really like the variable speed feature.. Today I was given a very heavy duty treadmill from a medical office, used for stress test and computer controlled. I did NOT get the computer controller. The treadmill has a 1.75 hp Baldor Industrial motor, 0-4000 rpm, 100volt dc with several control boards/heat sinks etc. Anybody have an idea how I can control this unit?

I'm pretty good with mechanical stuff, but, electrical stuff like this boggles my brain.

thanks,
karl


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## Tony Wells

TM's use a DC PWM supply. They can be built, but given the plethora, I'd just do a little curbside shopping when someone else tosses a treadmill.


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## karlw144

thanks for the ideas, there is a power supply with the treadmill, what's missing is the controler. I'm thinking of trying to find where the computer hooks up, and put a pot across those terminals. Everything is there except the computer that controlled the pre programed speed and elevation during stress tests.

karl


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## Tony Wells

Karl, have you hunted for a schematic of the machine?


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## karlw144

Haven't been able to find a schematic, not yet anyway. However, today I was given the EKG machine that runs the treadmill. There is a manual over ride that allows the operator to control the speed, otherwise speed and elevation are computer controlled. Next I'll see if there is some way I can separate the manual control from the rest of the machine. Hope to get the rest of the parts home tomorrow.

karl

thanks for all the ideas/help


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## karlw144

Well here is the good news so far. Got pretty good help from the treadmill supplier and from Baldor (supplier of 1.75 hp, 0-4000 rpm industrial motor and brushless DC Drive). Had to purchase a 5k pot ($3 at Radio Shack) and everything is running. With the pot turned to max resistance the motor still runs 20-50 rpm; need to interupt power to stop. Even at this low speed, you can't stall the motor. At min resistance the motor is screaming, and almost ZERO vibration! Need to figure out how to tweak min speed (there are a min speed and a gain adj. on the drive). Also, would like to be able to reverse the motor, not sure how to do that. There are 3 feed wires to the motor and 5 to the hall sensor on the motor. Some more work io do.

Want to thank all for their help and ideas.
karl


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## Tony Wells

Sound like you have made great progress, Karl. Keep us posted. Never know when that information will help someone.


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## karlw144

Well, here's the final situation on the Baldor motor. After I finally got it running, I found out that it was already in the "rev" mode, now I really need to figure out how to get it running in the other direction. The controller uses 115 ac input with output of 0-160 volts PWM 3phase to the 1.75 hp 0-4000 rpm brushless DC motor. By reversing 2 of the 3 power feed lines to the motor AND reversing 2 of the 3 Hall Effect sensor feeds I should be able to reverse it. This was recommended by the Baldor service engineer, not been tried, but could work! This was a "trial and error" process with the motor in a "run away" condition during the first several attempts. However, I finally hit upon the combination of motor feed wire/ hall sensor wire that reversed motor rotation AND gave me speed control. A couple more DPDT switches and I'll be all set. This is going to be a huge improvent on the 5 speed pulley change process. Now, on to the mounting brkts for the motor.
Thanks for all the help along the way,
karl


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## Joe Ford

Hi everyone,

I was looking in here and I have seen that you all know a lot about motors. I need a little help too 

I’m searching for a 5hp Baldor Single Phase to put on a compressor and I have stumbled upon these two: https://www.mrosupply.com/product/25387-Baldor_Electric_Motors-Motors_AC_Motors_Single_Phase_Motors and https://www.mrosupply.com/product/24875-Baldor_Electric_Motors-Motors_AC_Motors_Single_Phase_Motors.

Is there anyone who knows which is the best option, cause the price difference is obvious (the first one, Baldor L1430T costs $461 and the other one, Baldor L1430TM is $608). Somebody recommended this site to me https://www.mrosupply.com/index / for the good prices but if you know a better one please tell me.

Do you think there is a cheaper brand that shows the same performance?

Thanks,
Joe


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## Rbeckett

Joe,
I would think you could find a used or take off motor on Ebay or craigslist fairly easy since multi phase motors are hard to get power for in even some commercial shops.  Most folks dont want to fool with phase converters and they are kind of pricey so those motors seem to come up fairly often.  Do you absolutely have to have multi phase?  A single phase motor will turn a compressor if it has an unloader to open the valves on start up.  That would also probably be a much cheaper approach than 461 or 608 bucks.  For just a tad more you can buy a brand new Ingersol with an 80 gallon tank and 175 PSI peak.  Then you could add the current tank to your system as a resevoir and have plenty of air and a warranty for that much money.  I guess motors have gone the way of gasoline and car batteries.  I had to buy a car battery yesterday and it was over a hundred bucks for the cheapest one they had.  Just some thoughts.  This is a pretty old thread so you might also consider starting a new thread to start a discussion on what you are looking for.  Hope this helps..

Bob
I misread the original and that is a single phase but the price of a new unit at Tractor supply is pretty close.


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## Tony Wells

I'd contact a local motor shop to see if they had a good used motor if I had the need. Wouldn't hurt to contact scrap/salvage yards, as many show up on the junk market due to the copper value.


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## CluelessNewB

> Is there anyone who knows which is the best option, cause the price difference is obvious


                            The more expensive motor has a higher power factor so it would cost less to run.  In continuous use it would probably be the better buy.  If you are just a hobby guy the less expensive might be a more cost effective option.  (This topic probably should have been started as a separate thread since it's no longer about treadmill motors.) Surplus Center sometimes has good deals on motors  http://www.surpluscenter.com/home.asp


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