Motor Costs Comparison (more pro-electric)

[Rcmaster199 at aol.com]

Hi Dean, I agree with your assessment. The point is of course that the things 
you suggest are much easier and lighter to do in electric than on model 
engines, producing a more effective package overall. I am assuming that battery 
weight will come down over the next couple years, based on very new developments 
I am aware of.

Engine technology has progressed to the present offerings over the past 65-70 
years or so since the glow plug. Sure there have been advances in specific 
power, improvements in carburation and fuel delivery. New improvements will 
likely be of an incremental nature rather than fundamental nature and are likely 
to be smaller and smaller in the future. The point of diminishing returns was 
reached long ago.

The electric movement offers a whole 'nother way of looking at the power 
delivery to the prop(or wheels in a full sized car for that matter), and 
opportunities for fundamental advancement abound. Exciting times, limited only by the 
cleverness of its inventors. I am really looking forward to the time where fuel 
cells will be powering our models. That wouldn't be a bad project to work on.

MattK
Hi Matt,
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. 

just some ramblings,
    Dean
Dean Pappas 
Sr. Design Engineer 
Kodeos Communications 
111 Corporate Blvd. 
South Plainfield, N.J. 07080 
(908) 222-7817 phone 
(908) 222-2392 fax 
d.pappas at kodeos.com 
-----Original Message-----
From: discussion-request at nsrca.org [mailto:discussion-request at nsrca.org]On 
Behalf Of Rcmaster199 at aol.com
Sent: Friday, September 17, 2004 1:13 AM
To: discussion at nsrca.org
Subject: Re: Motor Costs Comparison (more pro-electric)


John there are at least a couple more good points:

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

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.

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. 

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

MattK
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