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Electric Stunt => Gettin all AMP'ed up! => Topic started by: Wynn Robins on August 20, 2009, 07:27:54 PM

Title: Spinners and Cooling
Post by: Wynn Robins on August 20, 2009, 07:27:54 PM

I was wondering how to get airflow over an outrunner if you have a spinner in place - I see Bob Hunt and Mike Palko have full spinners on their planes - but it appears they are running in-runner motors. 

Can you use a full spinner on an outrunner ?

Title: Re: Spinners and Cooling
Post by: Archie Adamisin on August 20, 2009, 08:19:21 PM

Wynn,

Consider this approach. (See atached picture)  It was used very effectively on a Brodak Oriental ARF converted to ECL using the Brodak Super Clown Set-up.  Another option is to slot your spinner to retain the shape, but allow air to flow into the motor. 

Mike is using an in-runner, but I believe that Bob is using an AXI out-runner.  This is where proper motor sizing is important so that the motor can handle the waste energy AKA heat effectively.  The better the cooling, the more aggressive you can go on smaller motor size to a point.  The best approach I have seen so far is my uncle's Mythbuster and the Radial cowl.  That motor runs at ambient temperature no matter how hot it is outside.

Take Care,

Archie Adamisin
Muncie, Indiana

Title: Re: Spinners and Cooling
Post by: Alan Hahn on August 20, 2009, 08:20:05 PM

Yes you can. As long as there is some airflow around the motor (and you have a physically large enough motor for the application) you will probably have enough cooling. Outtunners get their major cooling through the magnet bell. Not really that much air can get through the very tightly wound stator (IMHO  y1) .

If you are concerned, or if you are getting some serious actual motor heating, you can do some tricks, like use a prop nut (like the Dubro one I shown in the photo of my Vector in the "list your setup" thread. I get a lot of air entering the nose ring.

It all depends on what you may be willing to put up with.

I think Dennis A. included some air scoops on the nose of one of his stunters, and the latest has a cowl which resembles one you would see on a tightly cowled radial.

added: just went back and looked at some of the photos in the "List Your Setup" thread. Especially look at the planes that Will Moore has for some ideas. I think the radial cowl is the way to go for us.

Title: Re: Spinners and Cooling
Post by: Mike Palko on August 20, 2009, 09:41:48 PM

Hi Wynn,
   If all else fails a motor that uses a fan will help. I plan to use them in the future myself.

Mike