It's hard to say what are the specs, but speculating on the size of the battery pack, it's probably a 14.8V lipo battery pack. P = V * A, P=2KWm , 2 motors therefore P=1KW -> 1KW/14.8 =~67A. This is a relatively high performance brushless motor setup and it is not surprising, given the mass it is supposed to be moving (180lbs is a good guess for a human).
I bet their motor setup is custom designed to maximize efficiency so you won't find on the market the specific motors they are using. All that said, if you plan to do something similar, go with Scorpion Systems motors, designed in Germany and manufactured in Hong Kong, which are really good motors. You will need two motor speed controllers (ESC) and a way to generate a PMW signal as input to the ESC so to control the motor speed. See the specs of the speed controllers. Typically hobbyists use these motors for radio controlled devices .. so you can use a cheap transmitter/receiver setup, cost like $30 these days.
http://www.scorpionsystem.com/ ... you find distributors all over the web.
These are not cheap motors ... there are cheaper brands. Check HobbyKing.com Look for 14.8V (or 4 cells) motors. You'll need to find a motor with a Kv (number of revolutions per 1V of applied voltage) such that you get the required power at the desired spin rate of the motor , which depends on how fast you want the wheels to spin ... Ultimately what defines the power demand on the motor is the load .. and this is where this boostedboards guys are doing the hard part ... there is almost no way to limit the load ... the user does not know how much power he/she is demanding, because it depends on how fast the wheels spin and how steep the road is.
These guys are probably designing a speed controller smart enough to self control .. when Amps goes too high, it will likely reduce voltage before burning the entire system, which can happen quite fast.
It is an interesting idea and project... even though I wouldn't put my feet on an electric skate board ;-)
Please note that they use the electric motors as dynamic brakes. Standard ESCs available on the market won't let you do that ... not sure if there is such thing as an ESCs able to use the motor as dynamic brakes.
Hope this helps.
Regards
Century old motors were well built! And probably conservatively designed because electricity was new; they didn't know which corners you could safely cut.
In those days, everything mechanical was designed for easy maintenance; nuts, bolts, taper pins; simple tools to take the whole lot apart, adjust to take up wear, reassemble and use for another 10000 miles. Run out of parts? Turn another one to fit!
I had a 1910-era lathe still capable of turning within about 0.002" (traded it for a 1928 model!) and my 1840s watch is keeping very good time.
In an era of relatively cheap labour and expensive materials, this made sense. Who knows, we may end up back there some day!
Meantime it's worth studying how things from another era are made; partly to keep the skills alive and partly because good engineering is good engineering, from any era.
Just to clarify because this seems to have hit a nerve : I'm not simply equating long life with good engineering. What makes these motors good engineering is the skill with which they met their design goals using materials and techniques available at the time.
And long life was almost certainly one of them; reliability (not measured as MTTF but the ratio between MTTF and MTTR) i.e. easy repair, and efficiency. Swapping motors for a fix is not the issue; replacing brushes, re-lining bearings or (major job!) rewinding the motor was what happened - and what the motors were designed for. It's NOW we kinda-sorta-fix things by replacing motors.
We haven't improved THAT much on 92% efficiency in a motor in the last hundred years, but we do it with a lot less copper and iron. We can equally well admire a modern brushless motor with sealed bearings and no maintenance for ten years; they can both teach us something.
Best Answer
The casing is the flux return path for the magnets. If you replace it with plastic, the strength of the flux through the coils will be significantly reduced which will reduce the torque production efficiency of the motor. This will mean you'll need a bigger motor for the same amount of power output, so you'll probably gain nothing. Of course, if the motor is already too powerful, then this might be an option. It is hard to estimate exactly how much the torque production will be affected, but it would be easy to measure using the back EMF.
If you need to reduce weight a better approach would be to use stronger magnets (so they can be smaller) and replace the iron paths with magnetic material (such as a Halbach array pattern). Iron paths are sort of like plumbing for flux, so replacing them with active magnetic material essentially reduces the proportion of the motor mass that is 'piping'. The ultimate embodiment of these principles is the coreless motor which is a copper coil suspended between two magnets. These motors have very high power density.
However, I would imagine any modification other than removing the case is going to be too difficult for your situation, so you might have to look at alternative motors.