Hello i am thinking of buildind a skate from an mountainboard… does anybody know if there are available hubmotors to do this , i was thinking maybe using 2 hubs from electric scooter…
Why specifically hubs
Because its easier to assemble and they turn without energy…
Ytou might have got something wrong there
That is just wrong, they must be powered by midi-chlorians or something.
The problem with hub motors is you can’t gear down in a manner other than kV like you can with belt/gear drive. Makes it a lot harder to climb hills.
@professor_shartsis, did you finally complete your perpetual infinity drive?
I think they guy is saying yo can push them without major resistance.
hubs can free coast more easily than gear reduction drive. there’s still some resistance because the spinning magnets generate some eddy currents in the stator. if there’s a 3:1 reduction, the rotor magnets spin 3x faster past the stator for the same wheel speed so the eddy currents are greater.
Well yes but saying it that way is much less fun. Is joke
But why does that matter on a mtb @H6999pc
Theres good reason nobody really uses hubs of emtb builds.
Im not arguing that point, was just explaining :). I personally don’t know of any hubb motors other than hummies that I would run, every one Ive tried has been absolute garbage. I can’t image how bad hubbs with 8 inch wheels would be.
Long story short: For tiny hubs of that class you’re talking small diameter, so low torque, low power handling, so also low torque, there isn’t a lot of competition in that size range, so the stator laminations are probably going to be thick, increasing iron losses and making them harder to turn without power compared to more competitive and if you will, “modern” designs, and the power density compared to dirt-cheap outrunners is just silly. I wish a manufacturer made some decent ones, but the only way I see a DD MTB working is if you go to much larger “scooter” class motors that are competitive in design. We’re talking 13" and larger. …And then we start getting into lower efficiency and torque simply due to wheel diameter. Pump more power to compensate, and then you don’t have enough range, and congratulations, you have a snowball forming as it rolls down hill. Not worth it.
The resistance in hubs and direct drive is much more so cogging than eddy currents or hysteresis. The resistance when using a belt is the belt and pulleys friction and stuff. If u use motors with the right ratio of magnets to teeth that’s one way to greatly decrease cogging torque and get an easy coast.
You could skew the magnets or teeth to gain an easy coast, or other shaping of the magnets or teeth, but will decrease the max torque