stunthanger.com
Electric Stunt => Gettin all AMP'ed up! => Topic started by: Chuck_Smith on December 28, 2012, 03:51:59 PM
-
Guys, I'm drawing a set of fuselage plans for my first electric. (OK second, but I haven't built the first one and it's not going to have these issues.)
Since I want to have a jet inspired design I don't have an opening for motor cooling. The battery cooling part I get, but how much motor cooling do I need?
Looking at other designs I see some that look like conversions from IC that have little to no motor cooling. On the other hand I see some that have a designed opening between the spinner and cowl..think MIG 21 looking or a radial engine cowl. I figure I'll be using something like 450 Watts...seems like some cooling is in order.
Suggestions?
Next order of business...mounting. Rear mount? Front mount? Both? Both is a great answer, but if motor cooling is required it complicates things.
Any advice greatly appreciated.
-
Yes you need motor cooling. You don't need much -- a lot of folks around here make the opening behind the spinner about 3/8" diameter larger, to leave a 3/16" radius ring all around the spinner.
A small spinner with a larger cowl to look like an old-style intake+radome would look good.
-
Another option - I have not tried this yet but others on the forum have. TruTurn makes spinners with holes cut in the shell, then the back plate has fan vanes cut in it to pump air back into the motor cavity. I have tried just regular spinners with the nose cut off and holes in the backplate - helps keep air moving, however I suspect the Tru Turns would work much more effectively.
-
Chuck.
I see Dennis mentioned the TruTurn spinner option. Take a look at the picture I attached.....another idea to consider.
Happy Holidays.
Dave.
ama41041
-
Steve Whitman had a spinner like that on his Bonzo racer in the 1930's, with a radiator behind.
-
There's gotta be a suggestion in here someplace for a jet-age cooling scheme for an electric motor:
(http://upload.wikimedia.org/wikipedia/commons/0/06/Edsel_1958_grille.jpg)
-
Steve Whitman had a spinner like that on his Bonzo racer in the 1930's, with a radiator behind.
Steve Whitman invented quite a number of new concepts. His through the spinner cooling was quite a bit faster than versions of the airplane with conventional cooling. But he had difficulty in keeping the assembly together at higher RPM's.
Later the prototype of the Focke-Wulf 190 V1 also used a thru the spinner cooling with a small internal spinner just inside the outer shell spinner that was the diameter of the fuselage. This was soon abandoned due to excessive engine overheating and because they couldn't keep the pilot's feet cool.
After the war, Art Chester used it on his Swea' Pea and Swea' Pea II Goodyear racers. Unfortunately he was killed in the II when he stalled in a turn. It forced a change in the course from three pylons to six which lowered the g's pulled in the turns.