[motorin]

Hey everyone!

I’m working on creating a mock disc brake setup to demonstrate braking, and I’m trying to determine what type of electric motor I would need (with a variable speed control) to attach a rotor to that would give me around 3000/3500 rpm?

Let me know if you need any further information.

Thanks,

Josh

 

[Functional Artist]

It depends (it always depends) on the specific requirements that "you" need for your demonstration rig
...& budget (budget is always a huge factor)

IMO to just get a rotor "spinning" to be able to just show "braking action"
...then, a simple little 48V 1,000W MY1020 (~1.2HP) & controller combo, should do it (~$125.00)
...& a 48V batt pack like (4) 12V 12AH SLA's (~$100.00)

but,

If you need your demo rig to have the power to turn the rotor, while braking
...then, you'll probably need to go bigger

Something like a ME0708 (~5HP) (~$600.00)
...& controller (~$300.00)
...& contactor/fuses etc. (~$100.00+)
...& a batt pack to power it (~$?)

Plus, a "drive train" to "connect" the motor to the rotor & adjust the gear ratio (to your needs) like
...sprockets & chain
...or belts & pullies
...or maybe even gears

 

[piotrsko]

Actually @Functional Artist has a good idea for rough testing and a Ebike system barely ticking over should take no more than 20 volt, probably plugnplay if it's sensorless and had a throttle option which they all seem to have.

 

[motorin]

Hey everyone!

I’m working on creating a mock disc brake setup to demonstrate braking, and I’m trying to determine what type of electric motor I would need (with a variable speed control) to attach a rotor to that would give me around 3000/3500 rpm?

Let me know if you need any further information.

Thanks,

Josh

Appreciate the insightful information Functional Artist!

Instead of using a battery to power the motor, I was thinking I could use a regular outlet plug. Would that be an easier power supply versus using a battery?

Thanks,

Josh

 

[Functional Artist]

Um...no

These little motors (& batteries) work with DC (Direct Current) voltage.

Whereas, your regular outlet plug, outputs AC (Alternating Current) voltage.

You would need an AC to DC convertor (think battery charger)
...& it must be able to "output" 48V at up to ~20A

IMO a small batt pack would be your "best bet"

 

[Functional Artist]

Just thinking.
If you wanted a "plug in the wall" system, maybe look into an old washing machine motor
...or the motor off a belt driven, air compressor may work too
...& for speed control, look at (wood working) Router speed controllers

 

[piotrsko]

Riffing on that theme, a 1/2" capacity variable speed drill if you can tolerate the <2000 rpm.

 

[motorin]

Riffing on that theme, a 1/2" capacity variable speed drill if you can tolerate the <2000 rpm.

That might be a little light since I'd like to rotate an actual brake rotor. Thanks for the information!

 

[remy_martian]

That might be a little light since I'd like to rotate an actual brake rotor. Thanks for the information!

A half inch drill would have no problem at all rotating a brake rotor.

I think your wet thumb in the air has never been calibrated, based on what you just posted, so suggest you not use it in these here parts of the Interwebs.

 

[motorin]

A half inch drill would have no problem at all rotating a brake rotor.

I think your thumb in the air has never been calibrated, based on what you just posted, so suggest you not use it in these here parts of the Interwebs.

If you look at my original post dude, I'm looking for something that can turn 3000-3500 rpm. Perhaps a feeble-minded individual like yourself should read the original post first before talking out off your ass. Go play in the street kid.

 

[remy_martian]

If you look at my original post dude, I'm looking for something that can turn 3000-3500 rpm. Perhaps a feeble-minded individual like yourself should read the original post first before talking out off your ass. Go play in the street kid.

Dewalt DWD520K, among many:

https://www.mclendons.com/2833592/product/DeWALT-DWD520K

10A motor, 0-3500RPM, 120VAC.

@piotrsko, surprisingly, knew what he was talking about.

According to you, my source, just my butt, is apparently more resourceful than you are, grampa.

 

[SimonRafferty]

I would suggest using an industrial style single or 3 phase induction motor, coupled straight to the rotor.
Single phase, 2 pole would give 3600rpm straight off the mains outlet.

You will be able to run 3kW if you have a 230V outlet which will spin it up reasonably fast.

If you only have 115V, I'd consider a 4 pole motor which gives higher torque and a VFD which will run it at higher, variable speed.

Small industrial motors are surprisingly cheap considering how chunky they are - and very robust.

This is just a typical example.

 

[motorin]

Just thinking.
If you wanted a "plug in the wall" system, maybe look into an old washing machine motor
...or the motor off a belt driven, air compressor may work too
...& for speed control, look at (wood working) Router speed controllers

Would a washing machine motor like a Frigidaire 134638900 (200v) with a US 52 speed controller?

 

[kennybobby]

Probably not, it depends upon how you expect the motor to respond when you apply the brakes.

It would help if you explained your concept and what you are trying to do, why you need variable speed, etc.

To show how brakes work you could just spin up a rotor by hand, hit the brakes, watch the rotor stop!

 

[motorin]

Probably not, it depends upon how you expect the motor to respond when you apply the brakes.

It would help if you explained your concept and what you are trying to do, why you need variable speed, etc.

To show how brakes work you could just spin up a rotor by hand, hit the brakes, watch the rotor stop!

Hi KennyBobby... Essentially, I want to mount rotor to a hub (just like on a car), and then turn the hub via something electric that can turn up to 3000 rpm where I can control the rpm from 0-3000. I'm just focusing on the rotor part for now (which is where the speed controller would come in).

Hope this helps clarify any questions.

 

[remy_martian]

Clear as mud. You didn't answer why this is being done?

What is the point of spinning it to 3500 RPM, which is about 250MPH? Why does it need variable speed?

Without the vehicle's kinetic energy to absorb, spinning a brake rotor up to 3500RPM, or have variable speed, is nothing but a wank job unless you are building a rotor lathe, but even then, that's not just spinning it.

 

[kennybobby]

What is the point of spinning it to 3500 RPM, which is about 250MPH?

That's what i was thinking, ~750 rpm is ~ 60 mph

 

[motorin]

That's what i was thinking, ~750 rpm is ~ 60 mph

Go back in your mom's basement child.

 

[remy_martian]

Grumpy grampa in his garage, struggling to make his overunity machine work 😂

 

[floydr]

It is rather simple math.

60 mph = 812 rpm on a 15" tire?

Is this true? "a 15" tire of 195/65/15 is about 25" in diameter which is a circumference of 78" = 812 revolutions/mile and so 60 mph = 812 rpm. . . . 120 mph = 1,624 rpm 148 mph = 2000 rpm...

www.diyelectriccar.com

the 812rpm is for a 25 inch diameter tire.

To get an approximation multiply your diameter by 3.14, and then divide 63,360 by that number to get RPM at 60MPH

later floyd