DC Motor Controls: Get Help for Layman's Terms

In summary: Welcome to the PF.It sounds like you have not worked much with high voltages before, correct? What experience do you have working with AC-Mains powered circuitry?Hello BPress - welcome. I think this is very doable, but also very dangerous. The treadmills MC board will likely have a number of safety circuits, and if they are not all set properly it will not power up the motor.As I stated above, I know nothing about electric motors or high voltage, which is the reason I am here asking for advice. I'm not an electrician nor electronics expert. I'm just looking for advice on how this can be made to work, or
  • #1
bpress54
7
0
Okay, this is probably going to be way below your pay grade, but bear with me because I know nothing about electric motors except that you plug them in, turn the switch, and they work.

I've seen some instances where people have taken DC motors from treadmills and used them to power lathes and other equipment via PWM. It just so happens I have a PMDC motor from a treadmill that I'd like to use on my lathe. The motor has 4 wires (two are blue and according to the wiring diagram they are for a thermal protection circuit) and the specs from the motor plate are as follows: 2.6HP 21.4 Amps, 1.5 HP continuous duty at 95VDC.

I've been told this motor can't be used because the amperage is too high for a controller. Not sure what that means, but it doesn't make sense since it was used with a controller in the treadmill. I have the motor control board from the treadmill but no speed control. I attached everything and plugged it in but nothing happens, as I assumed it would.

Can anyone please help and tell me exactly what I need to make this work? Please don't be too technical, just give it to me in layman's terms.
 
Last edited by a moderator:
Engineering news on Phys.org
  • #2
bpress54 said:
Okay, this is probably going to be way below your pay grade, but bear with me because I know nothing about electric motors except that you plug them in, turn the switch, and they work.

I've seen some instances where people have taken DC motors from treadmills and used them to power lathes and other equipment via PWM. It just so happens I have a PMDC motor from a treadmill that I'd like to use on my lathe. The motor has 4 wires (two are blue and according to the wiring diagram they are for a thermal protection circuit) and the specs from the motor plate are as follows: 2.6HP 21.4 Amps, 1.5 HP continuous duty at 95VDC.

I've been told this motor can't be used because the amperage is too high for a controller. Not sure what that means, but it doesn't make sense since it was used with a controller in the treadmill. I have the motor control board from the treadmill but no speed control. I attached everything and plugged it in but nothing happens, as I assumed it would.

Can anyone please help and tell me exactly what I need to make this work? Please don't be too technical, just give it to me in layman's terms.
Welcome to the PF.

It sounds like you have not worked much with high voltages before, correct? What experience do you have working with AC-Mains powered circuitry?
 
  • #3
Hello BPress - welcome. I think this is very doable, but also very dangerous. The treadmills MC board will likely have a number of safety circuits, and if they are not all set properly it will not power up the motor.
 
  • #4
As I stated above, I know nothing about electric motors or high voltage, which is the reason I am here asking for advice. I'm not an electrician nor electronics expert. I'm just looking for advice on how this can be made to work, or if it is not possible or too difficult for someone who really knows nothing about it, what kind of DC motor and motor control do I need to convert my wood lathe from an AC motor with step pulleys to DC with variable speed? Is it possible to connect an AC motor to some kind of speed control device? Thanks
 
  • #5
berkeman said:
Welcome to the PF.

It sounds like you have not worked much with high voltages before, correct? What experience do you have working with AC-Mains powered circuitry?
As I stated above, I know nothing about electric motors, nor high voltages. My experience with AC mains powered circuitry is limited to household replacement of wiring, switches, outlets, circuit breakers, etc. I am not an electrician.
 
  • #6
bpress54 said:
As I stated above, I know nothing about electric motors, nor high voltages. My experience with AC mains powered circuitry is limited to household replacement of wiring, switches, outlets, circuit breakers, etc. I am not an electrician.
I asked because if you intend to make a lathe with an AC Mains powered motor, there are a number of safety regulations for how you handle the AC Mains connection from the wall to your lathe and motor. Things like how to size the fuse/breaker, where to put the switch, how to handle the grounding of everything, and how to make reliable connections. Also how to pick using a single-insulated or double-insulated transformer to transform the AC Mains input into the high DC voltage that the motor apparently needs.

If you are not familiar with any of those things, you really should not be undertaking this project. It's just too easy to electrocute somebody or start a serious fire. Please consider finding a Mentor in your area who can help you with your project, and teach you some of those safety fundamentals. :smile:
 
  • #7
Ok, I'm confused because this motor came out of a treadmill which plugs directly into a 120 volt AC outlet, and I understand that the controller board rectifies the AC to DC to power the motor. Basically all I want to do is replace the tread with the lathe spindle. The motor plate says it is 95 VDC, which to me does not seem like high voltage. When I hear high voltage I think 600+ or more. The lathe is already running on an AC motor at 120 volts on a 20 amp breaker. I want to go to DC in order to utilize a speed control, because as it is I must stop the motor and remove several covers to change the belt position on the 4 step pulley.
 
  • #8
Hello Again, Almost any voltage can be hazardous, but generally above 50V is considered hazardous ( this is the OSHA regulation point for electrical hazards) - what it is called does not matter, High Voltage or not, what comes out of the wall is lethal. PF is pretty strict on advising on hazardous projects.

There are certain best practices and procedures that qualified people utilize to stay safe on a project like this, I believe we pretty much all can understand what and why you want to do this. So the mentor / experienced partner recommendation is being given.
 
  • #9
My honest advice is try the hobbyist forums.I tried a search on phrase Treadmill Motor Lathe and got plenty of hits
here's first three.
http://www.cnccookbook.com/MTLatheDCMotor.htm

http://bedair.org/Tmotor/Tmotor1.html

There are so many people doing what you describe it doesn't make sense for you to start from scratch.

I once tried running a treadmill motor with just a bridge rectifier and ordinary lamp dimmer to see if it'd work, and it did, but the parts i used were underrated for connecting it to any sort of load. You'd need a 2000 watt lamp dimmer that costs one or two hundred bucks, probably more than something already made for the hobby market specifically to do what you want.

We could build one from scratch but you want a running lathe not an electronics research project.

That's my honest advice, not a dismissal.

old jim
 

Attachments

  • upload_2017-4-27_20-47-32.png
    upload_2017-4-27_20-47-32.png
    19.7 KB · Views: 556
Last edited:
  • Like
Likes RonL
  • #10
bpress54 said:
The motor has 4 wires (two are blue and according to the wiring diagram they are for a thermal protection circuit)

Can you show a picture of that wiring diagram ?
 
  • #11
Thank you Jim, finally an actual answer. I will send that wiring diagram later.
 
  • #12
Windadct said:
Hello Again, Almost any voltage can be hazardous, but generally above 50V is considered hazardous ( this is the OSHA regulation point for electrical hazards) - what it is called does not matter, High Voltage or not, what comes out of the wall is lethal. PF is pretty strict on advising on hazardous projects.

There are certain best practices and procedures that qualified people utilize to stay safe on a project like this, I believe we pretty much all can understand what and why you want to do this. So the mentor / experienced partner recommendation is being given.
<< Insult removed by Mentors >>
 
Last edited by a moderator:
  • #13
I am the son of a DuPont'r, and I was a safety coordinator / instructor for an electrical field service group... REF 1910.269 ( in this field High Voltage indicates > 70KV). I developed a philosophy that if you THINK you are safe you are not safe - you have to KNOW you are safe.

There are many places on the interwebs where there is no or little regard for electrical safety.. but on PF I have always respected their willingness to lock a thread in the name of safety.
 
  • Like
Likes rbelli1 and jim hardy
  • #14
Let me assure you that I have no desire to die nor start my shop on fire. I'm simply looking for an easy way to convert my lathe to a DC motor with an electronic speed control. That being said, and while I am not an electrician, I do understand the principles of electricity and realize that it can kill you. I am 62 years old and have been in the construction and wood working industry for most of my life and I still have both eyes and all of my limbs and digits, which should make you understand that I am safety conscious and careful in my work methods.
 
  • #15
bpress54 said:
Let me assure you that I have no desire to die nor start my shop on fire. I'm simply looking for an easy way to convert my lathe to a DC motor with an electronic speed control. That being said, and while I am not an electrician, I do understand the principles of electricity and realize that it can kill you. I am 62 years old and have been in the construction and wood working industry for most of my life and I still have both eyes and all of my limbs and digits, which should make you understand that I am safety conscious and careful in my work methods.
You simply do not have the skills yet to do this project safely.
Windadct said:
Hello Again, Almost any voltage can be hazardous, but generally above 50V is considered hazardous ( this is the OSHA regulation point for electrical hazards) - what it is called does not matter, High Voltage or not, what comes out of the wall is lethal. PF is pretty strict on advising on hazardous projects.

There are certain best practices and procedures that qualified people utilize to stay safe on a project like this, I believe we pretty much all can understand what and why you want to do this. So the mentor / experienced partner recommendation is being given.
And with that good advice, this thread is done.
 

Related to DC Motor Controls: Get Help for Layman's Terms

1. What is a DC motor control?

A DC motor control is a device used to regulate the speed, torque, and direction of a DC motor. It typically consists of electronic components and a controller that sends signals to the motor to adjust its performance.

2. How does a DC motor control work?

A DC motor control works by varying the voltage and current supplied to the motor, which in turn affects its speed and torque. The controller receives feedback from the motor and adjusts the input accordingly to maintain the desired performance.

3. What are the main types of DC motor controls?

The main types of DC motor controls are open-loop and closed-loop controls. Open-loop controls use a fixed input signal, while closed-loop controls use feedback from the motor to adjust the input signal and maintain a desired performance.

4. What are some common issues with DC motor controls?

Some common issues with DC motor controls include overheating, voltage fluctuations, and mechanical wear and tear. These can affect the performance and lifespan of the motor control and may require maintenance or replacement.

5. How can I troubleshoot problems with a DC motor control?

If you are experiencing issues with a DC motor control, first check for any loose connections or damaged wires. You can also use a multimeter to test the input and output signals and compare them to the desired values. If the motor control is not functioning properly, it may need to be repaired or replaced.

Similar threads

  • Electrical Engineering
Replies
6
Views
3K
  • Electrical Engineering
Replies
9
Views
1K
  • Electrical Engineering
Replies
11
Views
1K
Replies
2
Views
1K
  • Electrical Engineering
Replies
3
Views
2K
  • Electrical Engineering
Replies
1
Views
2K
  • Electrical Engineering
Replies
17
Views
2K
  • Electrical Engineering
Replies
7
Views
992
  • Electrical Engineering
Replies
5
Views
2K
  • Electrical Engineering
Replies
1
Views
936
Back
Top