[ron van sommeren]

I did not now where to post this message in the 'electric flight' subforum or here, it applies to both, therefore a cross-post to said sub-forum:
https://www.rccanada.ca/bb/viewtopic.php?t=6342

[Guest]

That is extremely cool. I am happy to see that the concept works because I have a friend working on a "direct drive" motor for a 60 size heli. It is about 150mm dia and will slip on to the 10mm main shaft.
This project is a long way from completion but I will get pics when ready.
Joe

[geink]

Hi,
Thats a big motor. Is he building it himself. I hear some vacuum cleaners have brushless motors,I was going to have a chat with the repair man down the street,I wonder if it passably to wind it to get the correct head rpm. I would love to hear about it.
thanks,
George

[Guest]

Yes, he is designing and building it himself. Shooting for Kv to be 54RPM/V and peak power to be up to 3Kw. Normal running power required for this size heli is about 700W to hover. If I remember correctly, outside diameter is 140mm, about 20mm thick. The motor is a ring around the outside with the center forming a centrifical fan for cooling. Rather than an output shaft, it will have a 10mm hole in the center so it can slide right on to the mainshaft.

It will use 56 magnets. The concept is to "unwind" a 14 magnet outrunner like a linear motor, put 4 of them one after another, and then roll it into a circle again. Electrically, it should act like 4 outrunners in parallel.

[geink]

Hi,
This type of motor is realy something spectactular,can we expect to see in the future, stators of a diameter of 6 inches, 1 ft, 2 ft, 4 ft. is there a limit.

George.

[ron van sommeren]

Hi George, outrunners have been around for some time already (decades). This company produces outrunners for busses and armoured vehicles:
http://www.magnetmotor.de/ (English link)

[ron van sommeren]

Now Niels Polfliet (Belgium) made a direct drive motor using Halbach magnet arrays:
http://www.rcgroups.com/forums/showt...68#post1919468