Motor Controller Power Supply

Thread Starter

mattrgs

Joined Oct 7, 2016
12
Hi all
First of all thanks for any help.

I have a 130V dc motor (1.34 kW) (see attached photo for more information) that I got out of a treadmill. I am using it in a homemade pottery wheels. However currently the controller out of the treadmill is complicated as it is computerised, so not easily changeable and modifications to it aren't possible. So therefore I am looking to fit a new motor controller.
I don't need to run it at full speed, at absolute maximum it needs to be half speed, if not lower. I have found a number of devices such as this: https://www.amazon.co.uk/gp/product/B016Y027DM that I think would work with it. However all of these kinds of devices require a dc input.
I have not managed to find a ac to dc converter that reaches a high enough voltage and power output. I am keen to keep this as cheap as possible, so am open to any suggestions.

Thanks
 

Thread Starter

mattrgs

Joined Oct 7, 2016
12
Thanks for your reply.
Whilst looking at similar projects, another solution came to mind:
I only need to run the motor at 240 rpm max. Using this simple calculation I think it says I need a lot less voltage: (240/3400)*130 = 9.2V.
Does this make sense, or do I need to take other things into account such as stalling the motor. I realise that at slow speeds I lose torque, but it is already very powerful, and if I were to use a 12 or 24V power supply I could run it slightly faster and use a pulley to decrease speed and increase torque.

This seems like a simpler solution if it works.
 

ronv

Joined Nov 12, 2008
3,770
Hi all
First of all thanks for any help.

I have a 130V dc motor (1.34 kW) (see attached photo for more information) that I got out of a treadmill. I am using it in a homemade pottery wheels. However currently the controller out of the treadmill is complicated as it is computerised, so not easily changeable and modifications to it aren't possible. So therefore I am looking to fit a new motor controller.
I don't need to run it at full speed, at absolute maximum it needs to be half speed, if not lower. I have found a number of devices such as this: https://www.amazon.co.uk/gp/product/B016Y027DM that I think would work with it. However all of these kinds of devices require a dc input.
I have not managed to find a ac to dc converter that reaches a high enough voltage and power output. I am keen to keep this as cheap as possible, so am open to any suggestions.

Thanks
Have you considered a pulley?
 

Thread Starter

mattrgs

Joined Oct 7, 2016
12
Ronv - I am already using a pulley to bring down the speed, but I need it to be variable whilst operating, and there doesn't seem to be an easy way to do this with pulleys.

MaxHeadRoom - I would be varying the pen between about 10% and 60%, would this vary the load too much, and why does this matter?
 

ronv

Joined Nov 12, 2008
3,770
Ronv - I am already using a pulley to bring down the speed, but I need it to be variable whilst operating, and there doesn't seem to be an easy way to do this with pulleys.

MaxHeadRoom - I would be varying the pen between about 10% and 60%, would this vary the load too much, and why does this matter?
You need to get the speed down to your maximum needed with the pulleys. Then when you add speed control you will still have good speed and torque control. If you can't do that you should probably pick another motor.
 

MaxHeadRoom

Joined Jul 18, 2013
28,688
If dropping the RPM from 3400 to 240 rpm for that 1.5hp Leeson DC motor is a little overkill for you application, equates to ~20HP output.
You might consider a smaller motor and a worm and pinion gear box.
Max.
 

Thread Starter

mattrgs

Joined Oct 7, 2016
12
Ronv - I was planning to use a 12 or 24v supply, if I use a 12v, that should give me a max rpm of : (12/130)*3400 = 314rpm. I think it is a 1.5 hp motor, and as I need just over 200 for maximum, that would give me 2.25hp of torque, and even if it was a 0.75 hp motor it gives me over 1hp torque which is still excess.
I was also looking at a 24V supply so with a pulley I can have more power and still achieve low speeds but at a higher voltage.
Alec_t - I assume a 12V battery wouldn't work instead of a car battery as it wouldn't provide the necessary current?
 

MaxHeadRoom

Joined Jul 18, 2013
28,688
Torque is equal to current, the torque capability will drop in relation to voltage/rpm.
You need to maintain torque by means of reduction.
Otherwise you would require some kind of closed loop feedback controller.
Max.
 
Last edited:

MaxHeadRoom

Joined Jul 18, 2013
28,688
Why not pick up a MC-60 T.M. ~$40.00 controller on ebay, just plug it in to a 120v socket.
A 5k pot controls the speed, they also have some degree of current feed back for constant rpm.
Those SMPS supplies are not that sturdy for a 1.5hp DC motor.
Max.
 

Thread Starter

mattrgs

Joined Oct 7, 2016
12
All of the MC60 motor controller are from the US (I am from the UK) so the cheapest is over £50 with postage, and takes over 2 weeks to get here. So its not the best option.
 

Thread Starter

mattrgs

Joined Oct 7, 2016
12
KB - £65 and above
Baldor - £110 and above

It did have a flywheel, but it was cut off, as it was causing issues due to its weight. From experience this hasn't caused an issue, it only means that it comes to a stop more suddenly.
 

ronv

Joined Nov 12, 2008
3,770
Ronv - I am already using a pulley to bring down the speed, but I need it to be variable whilst operating, and there doesn't seem to be an easy way to do this with pulleys.

MaxHeadRoom - I would be varying the pen between about 10% and 60%, would this vary the load too much, and why does this matter?
Here is another thought.
Use a 10 to 1 pulley.
Use a large lamp dimmer and a diode for the speed control.
 
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