Sunday, February 6, 2011

Powerful electric motors

I found this one for example:

Turnigy CA120-70 Brushless Outrunner (100cc eq)

With two of these a small single seater would fly quite easily.


Unknown said...

Actually,I think planes should use
small, weak but numberus built in engines, in the middle.This way, the plane would be balanced. 4 of these would provide enough lift to take off.
(the engines would come out from grooves from the bottom of the plane.)

M. A. said...

The trouble with off-the-shelf brush-less DC power is in the control circuit - the ESC in hobby terms. While a well known US manufacture has military contracts (Castle Creations), generally speaking I would be concerned more with how to manage the motor, than with the purchase or construction of a brush-less motor. A neat trick is to use multiple windings off of a common shaft - doubling the effective shaft HP of a given motor. You still have a trustworthy and government certifiable control system hurdle to pass.

Unknown said...

Could you illustrate your layout proposal?
I don't completely follow where this groove would be and how it would look like. Are you suggesting something like pylons on the HPA Alecto?

Jukka Takamaa said...


Jukka Takamaa said...

I will try to use these on my new lay out.

Unknown said...

Darrel: The never-ending problem is the certification. The ceritification is the very reason why personal aviation is starving.

Reliable control circuit is doable from scratch.
Everything that smells like certified aircraft part is probably bad quality. Like we have soon the fourth or fifth brushed motor fuel pump (each costing about 1500) in our plane going now. Incredibly bad quality, fails in no time because it is flawed by design. But certified and claimed safe. Yeah right. The electric parts which have been made for aircraft so far are generally pathetic. Also indeed, the turn coordinator that failed. Yes, that was fun. The electrical circuit was apparently done by some newbie amateur and hand soldered it. Certified too and claimed to be safe, but fails now and then. Electric technology can be designed such that it almost never fails, but not in current aircraft industry!

wanders said...

For things electric, especially brushless motors, I recommend the "Endless Sphere" forums - international, informed and a true wealth of information.

I would also look at Yuneec's motor and controller system. Pretty impressive, though not as small as the big R/C motors at Hobby King.

Much more impressive, but not yet in production, are the axial-flux motors from Lauchpoint Technologies in Santa Barbara CA, USA. 8.2 kW/kg, and VERY small.

I've just starting reading this blog, but evidently Karoliina's working on a serial hybrid. Even in a hybrid, the batteries are the weak point, at least in this part of their evolution.

wanders said...

The most power and compact motor technology uses an axial-flux geometry with a sophisticated Hallbach magnet array. The Launchpoint design is being marketed into UAV applications (see

You also have to respect Yuneec's motors - they are very close to production, presumably.

Nathan said...

If you're going to start from scratch with your BLDC motor control, you might be interested in TI's new technology, "InstaSPIN."

Is the certification trouble from Finland's or Europe's regulators? From what I hear, the US's FAA is really relaxed these days, which is encouraging a lot of development. Perhaps when you're done designing you might check into the red tape of other countries and choose a more accommodating government.

Unknown said...

Thanks for the tip.

What comes to certification:
Experimental aircraft can have anything the builder puts on it if it can be proven to work.
Getting IFR certification for the plane is then another hurdle, but basic permit to fly should be doable for about any powerplant.