DC Motor Question

[Windy Miller]

I have recently got hold of a 9x20 lathe that I would like to beef up a bit. One of the first mods that other 9x20 users recommend is to fit a bigger motor. Normally a DC one from a treadmill. I have bought a knackered treadmill, and it has a permanent magnet 130v 1.5 HP DC motor.

I have a few questions before I fit it:

Can anyone recommend a motor controller that will supply 130v? Ebay seems to have loads of 180v, 90v and 40v controllers, but I've not seen a 130v one. Is there usually a means to adjust/limit the max voltage? If so a 180v one will do the job.

My motor has angled brushes, rather than at 90* to the commutator. Will this prevent the motor running backwards? Is it possible/viable to redesign the brush assembly to mount them at 90*?

 

[rikrobson]

is there any reason it needs a DC motor?
Des the treadmill not have some sort of controller?

 

[Windy Miller]

I think it's because of the ease of varying the speed.

The treadmill does indeed have a speed controller, but it's combined with all the other usual treadmill functions, and I don't know enough about electronics to separate it all!

 

[Robotstar5]

The treadmill does indeed have a sped controller, but it's combined with all the other usual treadmill functions, and I don't know enough about electronics to separate it all!

Safety would be another issue, the faster the lathe goes, the faster you have to run to keep up with it

 

[Maker]

I think I've seen 120v controllers before, that might work.

 

[DanielW]

Are you sure the motor is not 180v DC? normally all motors on a treadmill are this voltage.

Is the treadmill electronics speed and power not working? as this is what should be used with the motor as its made for the motor.

I bought a used treadmill,I'm told it will give me a run for my money.

 

[DanielW]

I think it's because of the ease of varying the speed.

The treadmill does indeed have a sped controller, but it's combined with all the other usual treadmill functions, and I don't know enough about electronics to separate it all!

You can put everything in a box hidden away where the control side is concerned,alls you need visible is the way to control the speed and stopping and switching off of the controller.

 

[Windy Miller]

It's definitely 130v.

There is a problem with the control board, possibly the speed sensor, otherwise I would do what you suggest. The speed adjustment is push button, but I guess it could be converted to a remote rotary control.

My original intention was to do just what you suggested, but the board won't work.

Any thoughts on the angled brushes?

 

[piman]

Hello Windy,

the angled brushes are not a problem.

I'm not familiar with your lathe but AC motors are the normal choice, why pick a DC one?

Alec

 

[Windy Miller]

I think I've seen 120v controllers before, that might work.

If you could point me in the direction of one that would be great!

 

[Windy Miller]

Hello Windy,

the angled brushes are not a problem.

I'm not familiar with your lathe but AC motors are the normal choice, why pick a DC one?

Alec

See post #3!

 

[piman]

Hello Windy,

sorry I missed that but that's not normally required for a lathe, but as I say I'm not familiar with that particular model?

Alec

 

[Maker]

If you could point me in the direction of one that would be great!

When I acquired a treadmill motor I found loads of 120 volt controls but no 180 volt, now I can't find anything, sorry.
Does your motor have an encoder on one end?

Would it be hard to build a PWM controller from scratch?

 

[Windy Miller]

When I acquired a treadmill motor I found loads of 120 volt controls but no 180 volt, now I can't find anything, sorry.
Does your motor have an encoder on one end?

Would it be hard to build a PWM controller from scratch?

TBH I have no idea what an encoder looks like, but no I don't think it has one. There is a slotted disc at one end of the shaft that forms the moving part of the speed sensor, and a heavy flywheel. The other end has the pulley.

Building a PWM from scratch would be a last resort, as I know sweet FA about them. I'm happy to have a crack at it, but I'd need VERY detailed instructions!

 

[Maker]

There is a slotted disc at one end of the shaft that forms the moving part of the speed sensor

That's what I meant by encoder. I better have a look through all the crap I saved from the treadmill, If I can get the motor running I can post it to you if you want. I'm not likely to use it.

 

[rikrobson]

they are usually H-bridge PWM. The H birdge controls the direction and the PWM the speed.

I'm asuming that the lathe used the motor to controll the speed rather than a fixed speed motor and gearbox.

 

[Spark plug]

Why is it you want to go down the DC route?

DC motors are more of an American thing, they love them over there. But IMO they are high maintenance. If it's the speed control you want I would would much prefer a induction motor with a VFD.

 

[Windy Miller]

That's what I meant by encoder. I better have a look through all the crap I saved from the treadmill, If I can get the motor running I can post it to you if you want. I'm not likely to use it.

That would be VERY good indeed! Cheers Ears!

 

[Windy Miller]

Why is it you want to go down the DC route?

DC motors are more of an American thing, they love them over there. But IMO they are high maintenance. If it's the speed control you want I would would much prefer a induction motor with a VFD.

All the info that I have IS off American sites, but I'm open to different suggestions. I'll look into the AC motor & VFD thing...

 

[daleyd]

Why is it you want to go down the DC route?

DC motors are more of an American thing, they love them over there. But IMO they are high maintenance. If it's the speed control you want I would would much prefer a induction motor with a VFD.

In industry, apart from certain applications, they are pretty much all gone now in my experience, I certainly don't come across many.

Less maintenance, less electrical noise, easier control with an ac motor and inverter. Used to hate setting up newspaper/magazine printing unwinders/splicing machines with the old SSD DC drives on them......