Hoverboard CNC

Hi everyone,
I have stumbled upon a number or broken hoverboards and can salvage their motors (500W 36V, "inside the wheel " permanent magnet servo)

Do you think it will be possible to control and use them for CNC? They do have aluminium plates on both sides which should make it possible to attach them.
They can handle a standing person with ease.

What other things would you suggest i use them for?
Do you have any simple and cheap way i could get these under control? (arduino, drivers or such) I am a complete noob.
Thanks.

Yes, you can use them for motion control projects - sort of.

You indicated 'complete noob', so if any of this is too simplistic please forgive me.

First thing to figure out is how fast the motor spins at a given voltage. This will determine if it's useable for a particular application - if the motor spins at 30,000RPM at 36vdc, it's probably not useable to move an axis or similar without an expensively complicated speed reduction method. Look at the label or motor markings - or find a similar hoverboard and spend some time on the internet researching that (or very similar) motors.

If you determine that the motor RPM is in a range suitable to drive a belt, ballscrew, leadscrew, or rack and pinion then the next step is to get some additional components:

BLDC/Servo drive
Power supply
Encoder
Controller

An arduino can be used as a controller to send step & direction signals to the motor drive.

The motor drive accepts positioning, velocity, or torque commands from the controller, and energizes the motor (spins/moves it).

The encoder is mounted to to motor and provides position information to the motor drive, so the drive 'knows' where the motor is and how fast it's going.

The power supply takes your household 120V AC electricity and ceonverts it to whatever DC voltage the motor drive needs to run the motor.

Cheapest way to drive that motor is as a dumb motor. Buy a hoverboard speed controller & AC-DC power supply from Amazon or Ebay and hook it up. The motor should spin at whatever RPM you want.

If you want to position something - like a CNC device, robot, ect. - then the (possibly) cheapest way is:

Arduino clone
O-Drive (or similar low-voltage BLDC servo drive)
Power Supply
AMT encoder

But this arrangement is not simple for a complete noob. Even if you write no code yoruself, you'll still have to configure (ie. find and download instructiosn for the Arduino and O-Drive) the controller and drive.

Best bet before spending a dime is to poke around Youtube. There are quite a few videos from people who have converted RC quad or similar brushless DC hobby motors to some other purpose - like servo motor applications. Try searching for "BLDC servo".

Get a sense for what's involved, both hardware and software, and then have a go at it. It's only time and money.

Hoverboards are trending nowadays and increasing in demand day by day. Not only a source of self transportation but also a good source of having fun with friends and family. Check out these amazing gadgets on https://hoverboardsonly.com/ and enjoy your dream ride.

Thanks for the nice summary.

About the motor, theres nothing on it that i can identify it with.
But the the max speed is rated at 18 Km/h and the wheel is 53cm in circumference.
that gives me 300 m/min -> 566 RPM... and thats probably with a load. Seems to be a usable range.

I am a noob but im willing to learn, doesnt matter that it looks too complicated now.
On Youtube i have seen many uses for the hoveboard wheels mostly with RC ESCs. Even if i understand what all those electronic boxes are its hard to imagine using them since i dont know the details of their configuration etc.
Its like seeing someone drive a car and actually driving it for the first time. You get you need to turn the wheel but you dont get how to start it up.

Time to look up some more information.

Should be a fun and educational journey.

Found this - it's speed control, not positioning, but it's a good starting point:

https://docs.odriverobotics.com/hoverboard.html

So after looking up some BLDC basics and thinking about it i found my first starting project:
Making a hoverboard motor belt sander.

All it needs is a knob for speed control, on and off and the construction is simple enough as well.
I can use the hoverboards original charger as a source (42V) and reuse its construction for some parts.
I already found a control board that should allow this use:
https://www.aliexpress.com/item/1000...c003sNSRK&mp=1
or
https://www.aliexpress.com/item/3298...c003sNSRK&mp=1
The hoverboard run without a battery on just the charger just fine and the circuit on the board used 100V capacitors just like the more first controller option, so it should probably work.
The motor has hall so there is no reason not to use it. There were some other cheaper controllers that i skipped. There were also more expensive ones (double the price was the next closest) but the extra features it had i probably would not use in this build.
I already understand most of the pins and how to make it work in theory.

There are pins for external control of the velocity and those also accept pwm, so if i understand correctly, with a remote control application such as rc cars this would be fed by some rc pwm board? Seems simple enough.
For my use though a simple potenciometer is good enough. Them some emergency, regular and source switch and a switch for changing the spin direction, which i would also like to have controll leds so i see what direction is set (i guessi can just put them in series with the switch and a resistor since its a 5V input)

What i wasnt able to find is what the SC (signal control) output is used for. Is that supposed to feed some board that then displays the motors RPM? Because that would be a cool extra for a grinder to have.


The programmable odrive controller suggested above looks interesting That will be great for a second project, a drivable cart of some sort. The controller somewhat more expensive and complicated so i went with the easier build first

Get the one with the big caps, and get a cooling fan while you're at it. I suspect that when you load up the sander the speed controller is going to get HOT.

If you're going to be fiddling with these BLDC's, I'd suggest spending a bit more and getting a big controller. The Aliexpress or Chinese controllers are over-rated, so a 400w controller for a 400w motor seems like a good way to smoke the controller when you run the sander (or whatever) hard. I usually figure a 2:1 ratio when mentally discounting the specifications for cheap import equipment.

Find something that's already enclosed, maybe even water resistant, and comes with a speed control knob/pot. And still get a fan for it that's the same voltage as the controller input.

https://www.aliexpress.com/item/32657270269.html?spm=a2g0o.productlist.0.0.2e303d0 bIkBPbw&algo_pvid=2778c8b6-6327-4d45-b834-beebaee10844&algo_expid=2778c8b6-6327-4d45-b834-beebaee10844-41&btsid=0bb0624416006569585193813e111f&ws_ab_test =searchweb0_0,searchweb201602_,searchweb201603

The caps on the larger one are the same caps that were on the original drivers, thats a good point.
Then again the hoverboard probably doesnt get a physical resistance as large as a grinder could.

I have looked at a lot of the boards and they were all either 10 or 15A. Looking at slightly higher prices (30$) there were actually boxes using the same circuitboard.. just enclosed. Rating was the same with most of the expensive ones too,
Thats why i opted for these.

ill have another look if i can find something in the 1000w range.

There were also many e-bike enclosed controllers similar to what you found but i wasnt sure if id be able to make that work correctly with a potenciometer. They are most likely cheaper because they are more popular.
I have a big plate of aluminum that i can add as a cooler if needed. A fan is no problem to add but considering the dusty enviroment sanders can create it might not be a good idea.

Perhaps some fuse should be added?

No fuses between the controller and motor.

Check the max current output (DC) from the power supply and maybe fuse between it and the controller.

The enclosed model was suggested as metallic grinding dust is generally not good for live circuit boards. You're going to wind up needing a box of some sort, so by the time you make a heat sink, box, and mount a fan you can probably save time by just buying a controller designed for outdoor use (on an e-bike).

Good point.
I checked and the charger output is meekly 2A 42V,
Its not gonna blow anything up but the motor will be much weaker, i suppose.
I was thinking about a breaker between the supply and the controller, just to protect the board.
there will be wires, switches and knowing the charger is weak probably a power supply as well (36V 15A), so i will make some kind of enclosing regardless.
for first prototyping i might use the charger anyway.

You will smoke the charger quickly with any sort of load on it. It will overheat and die, or switch off and be angry.

Your best bet is to get a toroidal power supply, not a switching PS, rated for more amps than the motor is good for. Find a 48Vdc unregulated PS for about $150 and that will drive the motor controller & hub motor.

Should i really use a 48V supply for a 36V 3-phase motor?

Sorry, I misread the motor specs.

It won't hurt the motor - it'll just be able to spin faster. Keep in mind that voltage = speed, and amps = torque/power.

The big thing to avoid is a too-small power supply and too-small controller. Too-small meaning insufficient amps for the motor draw under load.