Motor Costs Comparison

[Jerry Budd]

Vince,

I don't think that's a good assumption at all right now.  In the 
month prior to the Nats this year I went through three battery packs 
(fortunately they were all covered under warranty and Thunder Power 
quickly replaced them with new).  Once at the Nats I made a few 
changes to the cooling, changed out the motor and speed controller 
with new zero time spares, and had no further problems.  In fact, I 
flew all but one of my contest flights at the Nats with the same new 
battery pack (in round 3 of the finals I had to use another pack 
because of the short turn time between flights).

I do think we'll get there with respect to battery reliability and 
longevity, but by no means are we there now.  Maybe by the end of the 
year or sometime next.

I've had no failures during charging IMO because I'm so anal about 
tracking battery temps and voltages post-flight (most of which I 
learned from Tony Frackowiak).  If something looks out of place I set 
it aside in favor of another pack and send in the questionable pack 
(most of the time it's pretty obvious when something's gone wrong). 
Also, even though all of my failures occurred in flight, I've never 
"lost" a flight akin to a deadstick landing or a flameout with a glow 
setup.  I noticed a drop in power, but never a complete system 
failure.  While typically I immediately landed, in most cases I could 
have continued the flight by managing the reduction in power with 
smaller more compact maneuvers than I might have otherwise chosen to 
fly.  I think most people who saw me fly at the Nats would tell you 
that I made NO attempt to fly small, so downsizing maneuver geometry 
a bit to finish a flight isn't at all unrealistic.  FWIW - I don't 
recommend continuing to fly with a failed battery (really a damaged 
cell) as a matter of practice due to the possibility (albet low) of 
the cell catching fire in flight.

The above experiences were gained over 49 flights with Tony F.'s 
ePartner during the month immediately prior to, and including the 
week of the Nats.  Tony has well over 300 flights on the ePartner 
since first flight in January, and he's had more problems that I did 
(he's failed at least one controller and one motor in flight), but 
understand he's been pushing the technology harder than anyone. 
Jason did it first and vividly demonstrated the potential.  Tony's 
been demonstrating the viability.  There are completely different 
issues associated with the later that take time (meaning a whole 
lotta flights) to fully "flush out".

BTW - Thunder Power and Hacker Brushless USA have both been great at 
supporting us in this endeavor, not charging for repairs or 
replacement, even when it's unclear what caused the failure, the 
electronics or the batteries (sometimes it's hard to separate the 
cause from the effect, or even which is which).  And FWIW, I'm not 
sponsored by either.

Note to Robert Gainey:  In the above paragraph, substitute "chicken" 
for "cause" and "egg" for "effect".  That'll make it easier for you 
to follow.   : )

Thx, Jerry


>Bob:
>
>Good job.  It will be very nice to get the the electric option in 
>your spreadsheet.  I think is fare to assume that the battery will 
>last about a year.
>
>Thanks,
>
>Vince
>
>-------------- Original message --------------
>
>Had some questions from the last contest, so decided to do a little 
>spreadsheet. Just comparing operation of the YS 1.40 DZ to the OS 
>1.60 (performance being roughly equal, according to feedback I've 
>received from observers of my setup).
>Not starting some battle; just providing some information that some 
>may find helpful.
><http://www.rcaerobats.net/MotorCostComparison.htm>http://www.rcaerobats.net/MotorCostComparison.htm
>
>Bob Pastorello
><mailto:rcaerobob at cox.net>rcaerobob at cox.net
><http://www.rcaerobats.net/>www.rcaerobats.net


-- 
___________
Jerry Budd
mailto:jbudd at qnet.com
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