# Anyone used this motor: HPDM-250 from H3X



## Tremelune (Dec 8, 2009)

Not much torque, but a fantastic form factor and top-end...My guess is that the price will be tough to swallow with Leaf motors going for $1,000, but it does look pretty sweet.


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## Hugues (Jul 13, 2014)

Indeed, I was surprised by the torque, my AC-23 has got more, although more volume, but power is impressive,


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## remy_martian (Feb 4, 2019)

Looks to me like marketing and engineering have a major disconnect. 

Aircraft rated, allegedly but:

1) Peak power (takeoff) rated for 30 sec
2) No max altitude spec

Both are showstoppers for aircraft propulsion.


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## brian_ (Feb 7, 2017)

I agree that the peak power duration is not long enough to be useful in an aircraft. While the optional planetary gearbox could make it suitable for a conventional propeller, I suspect that the intended application is some sort of multirotor VTOL or a design with several small propeller across the wingspan. Of course that doesn't matter in a motorcycle, but it raises suspicion regarding the integrity of the company.

The package could be appealing, and the continuous power density seems implausible, but the single most interesting feature to me is "3D printed copper stator coils". Really? These are their "AMcoils"; it makes sense electrically and magnetically, but the production process sounds expensive.



H3X said:


> The specifications are estimates based on electromagnetic, thermal, and structural simulations. Data from dynamometer will be available late 2021.


Translated, this means that everything is estimated from a computer model, and not even one prototype has been built. It will be interesting to see if it ever becomes real.


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## remy_martian (Feb 4, 2019)

VTOL is even worse on takeoff power, lol


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## brian_ (Feb 7, 2017)

remy_martian said:


> VTOL is even worse on takeoff power, lol


Yes... The VTOL comment was only about the use of a high-speed motor in an aircraft, not the takeoff power duration. 
A VTOL design should that assume full takeoff power is needed for the entire flight duration, since just hovering takes about as much power as flying at cruise speed.


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