
Hoverboard Teardown - fictivmade
http://blog.fictiv.com/posts/hoverboard-teardown
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Animats
No mention of the battery pack or charger, the most troublesome components.

The in-wheel motors are kind of neat. Those could be useful for motion control
projects, especially since they're three-phase synchronous and can be run all
the way down to zero speed with high torque. More info about the power drive
system for the motors would be useful. What are they using to switch all that
current? No heat sinks are visible, so either the switching is really
efficient or the drive electronics will overheat.

It's good to see precision motor control at this price point. These devices
are rather impressive technically. Once somebody starts shipping them with
safe batteries and full battery protection circuitry, they could be popular
again. Boosted brand electric skateboards got it right; they used a safer
battery chemistry, figuring the boards would be abused. Good call.

Most recent major hoverboard fire: Orlando, FL, 3 days ago. 3 apartments
destroyed.

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kens
If you're interested in a hoverboard battery pack and motor drive, take a look
at the hoverboard teardown that I did with iFixit:
[https://ifixit.org/blog/7821/swagway-teardown-
hoverboards/](https://ifixit.org/blog/7821/swagway-teardown-hoverboards/)

~~~
Animats
That's a more useful article. Thanks.

The three motor lead colors not matching is amusing. Those are three-phase
motors; any connection will work, but half of them will make the motor go
backwards. Swapping any two leads will reverse the motor. I wonder if, with
the colors correct, one motor is in reverse.

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zwieback
Might be a brushless DC, not an AC motor, although it's still basically a 3
phase setup.

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kens
Yes, it's pretty clearly brushless DC, since it's driven by an H-bridge and
has the Hall-effect position sensor. But as you say, it's still 3-phase, just
square rather than AC sinusoids. A description of brushless DC control is
here:
[http://www.nxp.com/files/microcontrollers/doc/app_note/AN405...](http://www.nxp.com/files/microcontrollers/doc/app_note/AN4058.pdf)

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mrfusion
My only complaint is that these feel really unstable at above walking speeds.

Is there a way to make the steering less sensitive at hi speeds or even lock
the two sides together?

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oxplot
When I see teardowns for most computers/gadgets, I'm always puzzled by the
size of the battery. Somewhere someone decided that battery life barely long
enough to sell the product, is good enough.

What I expect to see (and I do in Apple products for instance) is the battery
dominating the volume of the product.

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brianwawok
The average Apple product cost $890. The Average hoverboard cost $80.

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ck2
Now figure this one out:
[https://www.youtube.com/watch?v=KEDrMriKsFM#t=30](https://www.youtube.com/watch?v=KEDrMriKsFM#t=30)
(volume warning)

Best theory so far it is it just a quadcopter with some greenscreen video
photoshopping

But if it is somehow real, wow. Imagine THOSE all over your city.

That is the same guy who make the water based one that attached to jetskis

I just cannot fathom any portable powersource that would produce that much
energy for that much weight over 10 minutes. Even large scale RC engines have
weight limits below a fully grown man.

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dfcowell
He has a propellant tank on his back and it's clearly some kind of combustion
taking place. Still, seems a bit implausible.

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vox_mollis
As someone who came of age in the 1980s, the fact that these devices are
called "hoverboards" is extremely grating every time I hear it.

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mrfusion
What's the energy density on these batteries. I can't believe that tiny thing
can move 250 lbs around for over an hour.

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fictivmade
It's a 36 volt, 4.4AH Li-ion battery at approximately 172 grams. That puts the
energy density at about 915 wH/KG in ideal conditions.

~~~
mrfusion
Hmm I believe you but it just seems low for how much it does right?

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serge2k
Can we not call them hoverboards?

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supercoder
This comment is worse than the name

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shmerl
Why is it even called hoverboard? Quite misleading.

