Author Topic: 3HP DC motor 23Amp 100V DC 3250rpm Need Controler  (Read 186 times)

kvt85

3HP DC motor 23Amp 100V DC 3250rpm Need Controler
« on: February 23, 2020, 08:20:37 AM »
Was just given a big treadmill setup.   Has a 3HP continuous duty motor, 23a 100v DC that does 3250 rpm.  Need a cheep controller for it.   
This sucker is heavy. and seems to be heavy duty.   Came off a tread mill that they said was broken, but when a plugged it in and put a magnet where the safety strap was supposed to go.  IT worked fine.  So took it apart.  The motor had a 5 to 10 pound flywheel on one end and the belt drive on the other.  one of the biggest DC motors I have seen in a tread mill.   But have not seen a controller that will work on it.   Any suggestions.
 
Ken in SA TX

Jet 10x24 and Taiwan 10x24
Enco 30 mill
Sherline Lath and mill

Carpenter84

Re: 3HP DC motor 23Amp 100V DC 3250rpm Need Controler
« Reply #1 on: February 23, 2020, 08:30:30 AM »
Any chance you can use the treadmills controller? Or is it all digitally controlled?
That's a big DC motor and the controllers are pricy. You can find some KBCC, KBIC, or the like from KB electronics, but the vast majority of what you're going to find is for 1/2-3/4 hp. 1hp if you're lucky.
I had my lathe setup for DC - a treadmill motor. And after a year of more headaches than run time, I gave up on the whole setup and went 3ph with a VFD.
If you're bent on using the DC motor, you're going to need to do some searching or, spend some coin on a serious controller and figure out how to use it. DC motors are very current hungry, and eat up mosfets for dinner if the controller is not designed to deliver the amperage the motor wants. Especially if you're pushing the motor turn more torque than it was designed. Treadmills are plentiful for DC motors, but they don't crank out much in the way of torque normally. They will.... But you need a controller that'll push it without burning up.

Heat dissipation is everything for the controller. The controllers DO NOT like to be disconnected from the motor when under power (so, using some kind of interruption between the controller and motor for start/stop fwd/rev) do not start the controller without the motor connected and turning, it'll burn out.

... I'll stop now. Lol.
I have tons of information and experience on how to screw everything up DC - if you have questions...
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.

jpigg55

Re: 3HP DC motor 23Amp 100V DC 3250rpm Need Controler
« Reply #2 on: February 23, 2020, 09:40:17 AM »
If you have the original control board from the treadmill and it uses a bridge rectifier, you should be able to salvage that and use in conjunction with the PWM control of an Arduino.

Do you have a purpose in mind for it ??
A lot of people use treadmill motors for DC generators on windmill or water-wheel projects.
SB 9A, Clausing 8520, Sanford MG 612

jpigg55

Re: 3HP DC motor 23Amp 100V DC 3250rpm Need Controler
« Reply #3 on: February 23, 2020, 10:00:02 AM »
Just found a YouTube video where a guy used a SCR motor speed controller in series with a rectifier to control a 3 HP treadmill motor.
https://www.youtube.com/watch?v=BhuR74W1jWc

Here's another one:https://www.youtube.com/watch?v=_NmAFZMAfH8

Using the SCR with rectifier method will probably be the cheapest way to go, probably less then $50.
« Last Edit: February 23, 2020, 10:16:39 AM by jpigg55 »
SB 9A, Clausing 8520, Sanford MG 612

kvt85

Re: 3HP DC motor 23Amp 100V DC 3250rpm Need Controler
« Reply #4 on: February 23, 2020, 08:39:22 PM »
Prob way overkill but band saw was one thing I was thinking of.   Second was mill drill.   

One of the problems is I am not an electronics guy give me a single item and single voltage and I can do that but not much else.   
I do still have the boards from the treadmill.   The main board that controls it is bout the size of three sheets of paper laid side by side.   and it is digital.  The other part is about the size of a couple of boxes of checks.   and it used the metal case for the treadmill as part of the heat sink.   Which I thought was odd. 

Ken in SA TX

Jet 10x24 and Taiwan 10x24
Enco 30 mill
Sherline Lath and mill

Carpenter84

Re: 3HP DC motor 23Amp 100V DC 3250rpm Need Controler
« Reply #5 on: February 23, 2020, 09:34:12 PM »
The board with the heat sinks will be the motor controller. The bridge and mosfets generate a huge amount of heat. The three sheets of paper board is the user control board. That is likely no good to you.

Maybe you could post some photos of the motor controller. Iím more than sure itíll be a digital input which means youíll need a higher power of knowledge than I can offer, but, sometimes we get lucky and itís a basic kbcc style board.
Shawn

First 9x42 column mill,
Enterprise 10x28 lathe,
Ko Lee 6x12 surface grinder,
Airco dip/stick 160 welder,
Fully stocked wood shop.

jpigg55

Re: 3HP DC motor 23Amp 100V DC 3250rpm Need Controler
« Reply #6 on: February 24, 2020, 10:59:19 AM »
Pictures might help, but it sounds like the original controls used a PWM type speed control.
The basic way these work is the AC supply comes in to the main board where it seperates out into 2 or 3 different power supplies. One is the transformer/rectifier section that supplies power to the control board, one is the rectified power supply to the motor, and the other is for the linear actuator for the track angle adjustment (if it has one).
The last 2 mentioned could be a single if both use the same supply voltage. For the motor, speed control can be via PWM or a rheostat/potentiometer. From the sound of it, the control panel for the treadmill you have has push buttons for speed control which controls the PWM signel, otherwise it will have a dial for adjusting speed.

Based on your stated understanding of electronics and your intended uses, going with the SCR type speed control with bridge rectifier will be the easiest and cheapest way to proceed.
One thing that will be helpful is if you can get the size info of the big capacitor on the main power board. This is the component that maintains a smoother DC output voltage from the rectifier.

If you want precise PWM type speed control, there are people out there who are willing to build what you want, but it's going to cost.
SB 9A, Clausing 8520, Sanford MG 612

kvt85

Re: 3HP DC motor 23Amp 100V DC 3250rpm Need Controler
« Reply #7 on: February 27, 2020, 05:07:26 PM »
Well have to get my computer fixed it crashed big time.  So will take a while to get my pictures.   I do have all of it and can do it later.   
Will prob go on either the band saw or the Belt grinder.   
Ken in SA TX

Jet 10x24 and Taiwan 10x24
Enco 30 mill
Sherline Lath and mill