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<DIV><SPAN class=326065015-17092004>Hi Matt,</SPAN></DIV>
<DIV><SPAN class=326065015-17092004>I suspect that you're right, even if the
timeframe is a little longer. Some pieces of hardware are still lacking. The
first among these is a speed controller that offers braking. Probably the
easiest way to do this is to make the controller so that stick
position actually controls the motor RPM, and then mess with the timing to
get braking when the RPM is above the target. The potential for slow downlines
is staggering. For the geared motors, an RPM limit would also allow the
selection of a lower resistance , higher Kv, winding and corresponding change in
prop or gear ratio that would overspeed the motor under a W.O.T. dive, but
will improve efficiency everywhere else. </SPAN></DIV>
<DIV><SPAN class=326065015-17092004></SPAN> </DIV>
<DIV><SPAN class=326065015-17092004>just some ramblings,</SPAN></DIV>
<DIV><SPAN class=326065015-17092004> Dean</SPAN></DIV>
<P><FONT face="Times New Roman">Dean Pappas</FONT> <BR><FONT
face="Times New Roman">Sr. Design Engineer</FONT> <BR><FONT
face="Times New Roman">Kodeos Communications</FONT> <BR><FONT
face="Times New Roman">111 Corporate Blvd.</FONT> <BR><FONT
face="Times New Roman">South Plainfield, N.J. 07080</FONT> <BR><FONT
face="Times New Roman">(908) 222-7817 phone</FONT> <BR><FONT
face="Times New Roman">(908) 222-2392 fax</FONT> <BR><FONT
face="Times New Roman">d.pappas@kodeos.com</FONT> </P>
<BLOCKQUOTE dir=ltr style="MARGIN-RIGHT: 0px">
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT
face=Tahoma>-----Original Message-----<BR><B>From:</B>
discussion-request@nsrca.org [mailto:discussion-request@nsrca.org]<B>On Behalf
Of </B>Rcmaster199@aol.com<BR><B>Sent:</B> Friday, September 17, 2004 1:13
AM<BR><B>To:</B> discussion@nsrca.org<BR><B>Subject:</B> Re: Motor Costs
Comparison (more pro-electric)<BR><BR></FONT></DIV>
<DIV>
<DIV>John there are at least a couple more good points:</DIV>
<DIV> </DIV>
<DIV>Throttle response of an electric can be made more effective compared
to most engines, even many four strokes. You don't get the wind up on
downlines like you do on 2 strokes, and you don't need to wait until the 2
stroker settles down on landing</DIV>
<DIV> </DIV>
<DIV>I doubt we will ever have to worry about the motor "flaming out" on
take-off, 10 feet off the deck in no man's land, even if one cell drops. Or
the motor going fat or lean and flaming out somewhere in the flight.</DIV>
<DIV> </DIV>
<DIV>There are many more good points to be made. It makes sense for
pattern even if initial cost or the cost per flight is prohibitive
for many right now. Consider the afforementioned flame-out on take off, or
flame out on landing approach that got a little too far away. A cracked
pattern plane is often the result of either condition. </DIV>
<DIV> </DIV>
<DIV>I still hold to a statement I made more than a year ago: in five years
more than half of us will be flying electric</DIV>
<DIV> </DIV>
<DIV>MattK</DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV> </DIV>
<DIV> </DIV>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid"><FONT
face=Arial>Here are my thoughts on electrics:<BR><BR>Good points:<BR><BR>1.
They are VERY quiet. This is a good thing. I've never heard of
someone<BR>losing a flying site because the planes were too quiet.<BR><BR>2.
They are clean. The airframe will last longer because there's no
danger<BR>of being fuel soaked. Electrics are more "politically correct" in
that they<BR>don't pollute the air (although the energy required to charge
the batteries<BR>my come from something that does), and most of the new
batteries are safe<BR>when disposed of properly (to the best of my
knowledge).<BR><BR>3. They produce less vibration, even when the motor is
mounted directly to<BR>the airframe.<BR><BR>4. Modern brushless motors have
as much usable power as glow motors. When<BR>properly matched to the
airframe, an electric motor feels almost like a glow<BR>motor.<BR><BR>5.
They are easier to fit with a gear drive. This allows a wider range
of<BR>props that may be used.<BR><BR>6. Brushless motors require very little
maintenance.<BR><BR>7. The C.G. doesn't change as the battery
discharges.<BR><BR>8. They are easy to start.<BR><BR><BR>Bad
points:<BR><BR>1. An electric power system for large airplanes is VERY
expensive. You can<BR>buy a lot of glow fuel for the cost of a few battery
packs. Batteries are<BR>reusable, but they don't last
indefinitely.<BR><BR>2. Power system design is much more critical. Props,
gear ratios and current<BR>draw must be considered very carefully.<BR><BR>3.
Batteries must be charged. This takes a long time compared to how
fast<BR>they discharge. Owning a lot of battery packs merely delays the
inevitable<BR>truth: If it takes 10 times longer to charge than discharge,
eventually you<BR>will end up waiting for something to charge.<BR><BR>4.
With LiPO's the energy density is fairly high (capacity wise) but
it<BR>normally takes quite a few packs in parallel in order to handle the
required<BR>current loads.<BR><BR>5. LiPO's must be handled with care. I
don't need to elaborate on this one<BR>although I personally don't think
they're DANGEROUS. People are more<BR>dangerous.<BR><BR>6. High output
electric power systems are relatively heavy, although this is<BR>improving
at a rapid rate.<BR><BR><BR>To sum things up - I fly glow and electric. I
like them both. I have a few<BR>S400 planes that fly very fast and track
very well. I also have a few slow /<BR>park flyers that are great when the
air is calm. Small electrics are great.<BR>Most of the time, however, I
prefer glow motors. Mostly because of cost and<BR>ease of use. A .40 glow
motor costs $50.00 (used) to $100.00. A brushless<BR>motor and battery that
provides equivalent power could easily cost 3 times<BR>as much. I don't like
to wait for batteries to charge. I hated it when I<BR>raced R/C cars and I
hate it even more now. I don't mind wiping the slime<BR>off of my plane at
the end of the day. I do believe electrics may be the way<BR>of the future.
The key word is future. At the present time, I think the
best<BR>bang-for-your-buck comes from the glow stuff. There's a lot of
energy stored<BR>in dead Dinosaurs, and we pretty much perfected how to
extract it in the<BR>'70s. If money is not an object and you want to be a
pioneer then fly 2<BR>meter electrics. I think I'll wait until technology
catches up with our<BR>expectations.<BR><BR>John
Pavlick</FONT></BLOCKQUOTE></DIV>
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