Hi Guy's This week I am picking up a treadmill for the motor.It is a 12v 3.0 Continuous horse Power with a 4.5 Hp peak.Would the controller in the link be all I need ................https://www.ebay.com.au/itm/DC-6-60...e=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649 .............. This next unit will allow reverse and has a built in fan so I am leaning more towards it https://www.ebay.com.au/itm/Digital...e=STRK:MEBIDX:IT&_trksid=p2060353.m1438.l2649 Many thanks for your time

 

So this is a 12V .. 3HP motor??? 3HP is about 2.4Kw ... that means current will be 200A !!!

None of those controllers will handle that current ..

If you give more details of what you are building we might be able to find an easier solution.

 

So this is a 12V .. 3HP motor??? 3HP is about 2.4Kw ... that means current will be 200A !!!

None of those controllers will handle that current ..

If you give more details of what you are building we might be able to find an easier solution.

I am building a 2" x 72" belt sander and yes 12v 3hp motor

 

FIrst post the motor and its specs please. The label on it will do.
Second please post a circuit.

 

FIrst post the motor and its specs please. The label on it will do.
Second please post a circuit.

Picking it up this week ......

 

I find it difficult to believe the motor is 12 volts. Are you sure it is not 120 volts and the zero has rubbed off ?

Les.

 

I find it difficult to believe the motor is 12 volts. Are you sure it is not 120 volts and the zero has rubbed off ?

Les.

I am in Australia we are on 240v https://www.fitnessmarket.com.au/shop/nordictrack-t15.0-treadmill.html

 

Why do you need to take this motor and control it separately? There is a controller inside already. $1800 is a lot to make experiments.

Its not a 12VDC motor. Its probably as 230VAC motor, like stated in the above post.

Can we have more details on your project intentions? Are you intending to build this machine by yourself?

 

Why do you need to take this motor and control it separately? There is a controller inside already. $1800 is a lot to make experiments.

Its not a 12VDC motor. Its probably as 230VAC motor, like stated in the above post.

Can we have more details on your project intentions? Are you intending to build this machine by yourself?

The motor control board is not functioning I paid $60 AU for the treadmill.I will be using the motor to drive a 2" x 72" belt grinder and will be building it myself.These grinders are best made with 12v motors or 3 phase with a variable frequency drive to allow single phase plug in.The grinders are made with variable speeds to account for different materials or knife making.It would be doubtful that the motor would be 240v due to the different speed variables of the treadmill (1-22 klm p/h)

 

I guess TS must be getting this for next to nothing ... good news is it already has it's own speed varying circuitry built in ..

So if it's functioning you already have a belt sander with it's own speed control on board ,,, all you have to do is get some carborundum grit embedded in the rubber belt that's already on it ..lol .. maybe get the carborundum powder hot and sprinkle it on..

This is certain to run on mains electricity , best to change the electronic side as little as possible and use the controller it already has.

 

The motor control board is not functioning I paid $60 AU for the treadmill.I will be using the motor to drive a 2" x 72" belt grinder and will be building it myself.These grinders are best made with 12v motors or 3 phase with a variable frequency drive to allow single phase plug in.The grinders are made with variable speeds to account for different materials or knife making.It would be doubtful that the motor would be 240v due to the different speed variables of the treadmill (1-22 klm p/h)

Ahhh ... to get new circuitry to control this maybe quiet expensive , wait till it arrives , see what the motor is .. Ideally the control panel can be fixed

 

These grinders are best made with 12v motors or 3 phase with a variable frequency drive to allow single phase plug in.

Your thinking that all DC motors are 12V, but they aren't. It is a DC motor though and the voltage should be on the motor tag. And as a hobby knife maker and a career machinist, your wrong about belt grinders "having" to be variable speed, most aren't. The specialized knife ones may be but only the 'deluxe models' and that is for the different size drive wheels, to get the correct surface feet per minute speed. But even this isn't as important as some people make it out to be.

 

This is basically what I will be building

 

The motor on this product is described as "digital"

"The term digital motor appears to have been invented by Dyson for marketing purposes. The fundamental principle is same as for all electromagentic motors.

Digital motor is patented technology. It can run at variable speed, variable tarque with high efficiency. The efficiency of the motor is 95% or better. It generates no heat. The motor is controled by digital computer."

 

"Digital Motor runs on same principle. There is a Stator which is static and is either magnet or coil which produces magnetism, and a Rotar which is rotary, again magnet or coil and produces magnetism. The principle is if electric field is applied to magnet at right angle, the resultant force will be 90 degrees to both known as “Right Hand Rule”.

If Stator is magnet then Rotar will be coils. This is common in DC motors. Brushes or contacts are used to power the rotar. The rotar will have 3 or more coils at equal angles. At any given point power will be applied to only one of these coils which will react with magnetic field resulting in small rotation. The brushes disconnect the contact for that coil but connects to next coil. This will again force it to rotate further and the process repeats. The motor rotates steadily at a speed determined by magnetic field and the voltage in the coil.

If you use coils for Stator and magnet for Rotar, then this eliminates brushes as no power is required for magnets. Again you will have 3 or more coils arranged in equal distance. Without the rotary mechanism to shift the power around these coils, you need to power each of these coil through digital circuitry. Hence the term Digital Motor. If you have 12 coils arranged at an angle of 30 degrees to each and apply enough power to one of the coil so that the magnet deflects and rotates the shaft to 30 degrees. Now shift the power to next coil and the motor rotates another 30 degrees. Thus you can control the rotation angle and speed of the motor. More coils, more control. Because no brushes are used, the noise generated by contacts are eliminated.

It is Dyson who coined the phrase Digital. Like many other gadgets around this is not new. Though in computers it is normally called as Stepper Motor. Stepper motor is very popular in digital circuitry. The magnets instead of just being two poles, will be a number magnets mounted on a circular wheel at equal angle. The wheel itself will be connected to a gear. Applying a small pulse to the coil will deflect the magnet slightly bringing the next magnet to face the coil. More accurate steps can be obtained by controlling the pulse width (or the duration of time power is given) to the coil. Since precision of rotation is important in magnetic discs, stepper motor is commonly used."

 

Your thinking that all DC motors are 12V, but they aren't. It is a DC motor though and the voltage should be on the motor tag. And as a hobby knife maker and a career machinist, your wrong about belt grinders "having" to be variable speed, most aren't. The specialized knife ones may be but only the 'deluxe models' and that is for the different size drive wheels, to get the correct surface feet per minute speed. But even this isn't as important as some people make it out to be.

All the treadmill motors I have seen are 12v not saying that there isn't different voltages out there though.I wish to use this grinder for timber and steel hence the need for variable speeds

 

My guess is the specs on the motor are over inflated by the treadmill manufacturer for marketing purposes. Other examples show that it should have plenty of power for your use case, but probably it is not a true 3+ HP motor.

 

OK ... this is becoming clearer ... The motor is a brushless DC motor .. it should have three wires coming out ...

It could run on 12V , but mains will be feeding the circuitry , which controls the motor .

Radio control planes and helicopters use brushless motors , and some can be quiet large , KW , so you could use the same circuitry they use , but the circuitry needs a low voltage DC supply

 

My guess is the specs on the motor are over inflated by the treadmill manufacturer for marketing purposes. Other examples show that it should have plenty of power for your use case, but probably it is not a true 3+ HP motor.

The treadmill has 3 hp continuous duty with a 4.5 peak.The company that sells these make a strong note of not over inflating motor size.I guess if they were they would state 4.5hp they say they are a taiwanese DurX™ Commercial Pro motor .The motors come with a lifetime warranty

 

I think this is one of there latest models it has a 4.25chp motor ......
4.25 CHP MOTOR
Train safer, longer and quieter. Built with a bigger motor case for less vibration and dual cooling fans for less heat, this 4.25 continuous horsepower DurX™ Commercial Pro motor delivers lasting power that's smooth and even. Every NordicTrack drive system features high-grade insulation and a built-in grounding brush to protect the motor and make it run longer. We're so confident in its performance, we've backed it with a lifetime warranty.
https://www.nordictrackfitness.com..../25/nordictrack-commercial-2950/10495/details