Question :
Stock speed 400 brushed motor came with a 3:1 reduction gear and 12
inch prop (slow flyer).
Can I use the same gear and same propeller for a speed 400 brushless
(not outrunner) or there is more to it?
Thanks
Tim Wescott - 30 Mar 2006 21:38 GMT
> Question :
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Assuming that you get a brushless with the right Kv rating you should be
able to turn the prop a bit higher speed at the same power as the
current brushed motor. Geared brushless motors seem to really shine
when you run them _fast_, which would indicate using a higher voltage
(or lower Kv motor) and a smaller prop or more reduction in the gear box.
It all depends on what you want. If you want to go straight up forever
with that poor little Cessna then you probably need to gear down more
and put a really fast motor & powerful in there. If you just want
sustained inverted flight then the right motor with that gear/prop
combination may be just the ticket.
If your LHS is really good you could just ask there.

Signature
Tim Wescott
Wescott Design Services
http://www.wescottdesign.com
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The Natural Philosopher - 31 Mar 2006 11:50 GMT
> Question :
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> Thanks
Yes, provided it physically fits, the brushless is an inrunner and will
work at an appropriate RPM when geared, and you take account of the
likely different motor characteristics when selecting the pack/prop.