Model Forum / Radio Controlled / Air Models / May 2004

Is it helpful to add that the only thing I need to remotely control is on
and off?

I think I want an aircraft motor because I think they are designed to be the
fastest and most powerful that I could buy today.  I'll probably keep the
propeller and wings, but maybe not.

Tony

My local hobby shop said that more voltage generally means more power.  I
thought it was amperes that made a certain propeller spin faster.  Are we
both right?  Either adds more weight.  So, now we're starting to get to the
trade-offs that are really at the heart of this issue.  Comparing specs
alone doesn't seem to help.

silly question. Get a brushless motor some lithium polymer batteries and
a sleek airframe. Some of the gliders can do ove 80mph, so how fast is
fats enough?

Its a stupid question. Almost any medieum sized electric motor will get
you up to the 70mph plus region in the correct airframe and with the
correct battery pack and prop.

ah. a Race. WHAT race?

neither of those are fast. Try a multiplex twinjet. That should get you
over 50mph at least.

Not really, especially once you learn about Motocalc.

Perhaps the giant solar powered one that NASA crashed into the ocean a
year or so ago?

Then you probably want some sort of pylon racer with a large brushless
motor and a direct drive prop.  200 mph ought to be possible if you
throw enough money at it.  (Oops, I mentioned price, sort of.)

Though I suspect you really don't understand what you're asking.

Um, why?

Then they're idiots.  The 540 has more power.  The 540 is a much
larger motor than the 340.

No, but it's a large factor.  The Aerobird Extreme is a lot larger
than the J-3 cub, so it needs more power.  They both probably fly at
similar speeds, however, though the Aerobird might be a bit faster.
Neither one is very fast in the grand scheme of things.

Tony - I've combined your posts to respond;  it sounds like you're planning
to use the power system from a plane to power something else?  Please tell
me this is the case, since you only need "on and off" control  :^)

If that's the case, you'll want to skip the purchase of the plane entirely
and concentrate solely on the motor, prop, and battery pack.  Any "stock"
configuration offered with a ready-to-fly plane will almost certainly
underperform what you can put together yourself.

If you want to go faster, bigger is better!  The most powerful motor I have
used to date is an AXI 2420/12 (brushless outrunner) on a 10 cell (12 volt)
NiMH pack with a Graupner 11x6 prop.  And it SCREAMS in the air!  There are
bigger motors if you feel so inclined to use them...

Yes, more volts means more power.  Add cells to your battery pack to
increase voltage, and make sure that the motor is large enough to handle the
volts delivered to it.  Different props will draw more or fewer amps.
Choose a prop that pulls about as many amps as the motor, battery, and speed
control (if there is one) will handle.  Choose battery cells that can
deliver amps at the rate you intend to consume them.

Dan.

the

"Tony Jacobs" <tusk@comcast.net> wrote in message
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