Cost of electrics

[Keith Black]

I put the questionnaire on electric pattern in the Pattern forum. Here is
the link:

http://www.rcuniverse.com/forum/Electric_Pattern_Pioneers_%2D_Please_share_your_experiances%25%25%25/m_2320900/tm.htm

Keith Black

----- Original Message ----- 
From: "Grow Pattern" <pattern4u at comcast.net>
To: <discussion at nsrca.org>
Sent: Tuesday, November 23, 2004 7:23 AM
Subject: Cost of electrics


> Keith,
>           Which forum on RCU did you use to make the post?
>
> I would add that controllers used at their limits do go up in smoke.
>
> Also I have stripped gears and even snapped a shaft when the prop has
> touched the grass. (These electric props are up to 7" bigger in diameter
> than the glow props).
>
> This was a big surprise and left me with no way to fix it at the field.
The
> motor had to be returned to the manufacturer. Also swapping the motor at
the
> field was not an option due to the need to use a high rated soldering iron
> to disconnect/connect the motor.
>
> It seems that the field-support-solution is to have a motor already
> pre-wired to the  controller, or the use of some really good low
resistance
> connector(s).
>
> It's still a big learning curve that's for sure!
>
> One final observation from the judges chair at the Nat's. I saw the YS
> 1.60's operate against the electric of Jason's plane. They all did well!
> Jason won because of he flew the conditions better than the others.
>
> Regards,
>
> Eric.
>
> ----- Original Message ----- 
> From: "Keith Black" <tkeithb at comcast.net>
> To: <discussion at nsrca.org>
> Sent: Tuesday, November 23, 2004 1:34 AM
> Subject: Re: Electric power WAS : Diamond stab cross section - Dean Pappas
>
>
> >A few weeks ago I put together a list of questions directed to those
> >already
> > flying electric pattern in hopes that their responses would help those
> > considering electric pattern. Unfortunately there were no responses to
the
> > questionnaire on this mailing list and only two responses on RCU (thanks
> > to
> > Steve K. and Tony F. for responding).
> >
> > Based on the information I've been able to gather via these responses
and
> > other extensive sleuthing I'm not convinced that the technology is at a
> > point that it will meet "my" objectives. This is not the result I wanted
> > from the research, but it's what I concluded.
> >
> > My key concerns are 1) flight time, 2) reliability, and 3) life-span of
> > batteries.
> >
> > 1. Flight Time: From what I can tell the max reasonable flight time
today
> > seems to be around 10 minutes. There are batteries with more capacity,
> > however this comes with a weight penalty. Also, I don't think the
limited
> > time is purely a battery capacity factor, I think there are also
concerns
> > about how log the batteries can supply the high amp load before being
> > damaged or getting too hot. If someone has some hard facts on this
please
> > speak up.
> >
> > For me 10 minutes per flight would be a big step backwards since I
> > normally
> > fly 15 to 18 minutes per flight. Being a new Advanced pilot I have a LOT
> > to
> > learn and just can't accomplish this without putting in a lot of stick
> > time.
> > Also, since my practice time is limited I need to knock out three of
four
> > 15-18 min flights in a pretty short time. I can't just sit around the
> > field
> > all day.
> >
> > 2. Reliability: I am 100% confident that a brushless motor operated as
> > designed will last longer than most pattern planes. Brushless motors are
> > extremely efficient and the ideal power plant. However, there are other
> > things to consider. 1) Will the motors hold up under the 60+ amp loads
> > over
> > time, heat may be a problem. 2) How are the gear boxes holding up (where
> > applicable)? and 3) How will the ESC (Electronic Speed Controls) hold
up?
> > I
> > know from observation and experience in other electric applications that
> > ESC's get burned out, sometimes much more often than the electric guys
> > want
> > to admit. Through all the research I did related to electric pattern I
> > wasn't unable to find anyone that has hundreds of flights on a single
> > speed
> > control and motor combo. It may be possible, but no one out there is
> > admitting to such luck.
> >
> > 3. Life-span of batteries: This of course is the thing that everyone
zeros
> > in on as the cost of operation. Assuming the motor and ESC don't need
> > frequent repair or replacement then we need to make sure we get enough
> > flights per battery pack to justify the $700 per flight pack. On a
> > personal
> > note I'm not looking at electric as a cheaper alternative to glow. I
would
> > go with electric even if it's incrementally more expensive because there
> > are
> > many other benefits that to me justify a premium. However, the most
> > flights
> > I've heard on a single pack is around 100 flights. I've also heard of
many
> > failures long before 100 flights. In fairness much of this may be due to
> > early adopters of new technology. In most of these cases I think the
mfgs
> > are replacing the batteries. With the new higher C rated batteries the
> > most
> > I've heard of is around 50 flights. I'm not saying they die after 50,
but
> > I've not found anyone that has exceeded that yet, possibly because they
> > are
> > relatively new.
> >
> > I'm not suggesting that my findings are all accurate. I'm just sharing
> > what
> > I've been able to ascertain based on what others have been willing to
> > share.
> > I'd love to learn that indeed the current state of electric is much
> > further
> > along because I'm anxious to go electric when the technology is mature
> > enough to meet my needs. If I felt that were the case I would strongly
> > consider going with electric on my winter project.
> >
> > Keith Black
> >
> > ----- Original Message ----- 
> > From: <JonLowe at aol.com>
> > To: <discussion at nsrca.org>
> > Sent: Monday, November 22, 2004 2:33 PM
> > Subject: Electric power WAS : Diamond stab cross section - Dean Pappas
> >
> >
> >> I hope Jason Shulman pops in here on the cost of electrics, but I
> > understand that the big electrics are getting nowhere close to 1000
cycles
> > out of their batteries.  What I hear is less than 100 cycles, in most
> > cases
> > CONSIDERABLY less.  Why, I don't know.  At $600 a pack, the cycles you
get
> > will change the cost effectiveness a lot!
> >>
> >> Jon Lowe
> >>
> >
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