3200s--some (more)thoughts E stuff

[Richard Strickland]

Hey Guys,

Since there seems to be some interest in how things are developing with the
smaller packs, I thought I would pass this along.  I make the statement that
the systems are not equal to 160s and high
nitro--Explaination/clarification--They are fine for wide open patterns if
you have plenty of capacity and can make weight.  The compromise in this
project is to arrive at the lightest battery systems that will do the job
with reasonable life--3-500 cycles.  I knew I was running the packs too
hard--they are rated 20c and I was peaking at 21-22c.  I was getting
reasonable temperature rises as long as things stayed in balance and were
getting good charges.  I also practiced fairly 'small'.  To get to the
minimum level will take OPTIMUM 3200 packs, a reasonably light airplane with
good constant speed characteristics flown well fairly close in.  No
problem(cough).   With balancing chargers, that may turn viable--we'll
see--but it'll be a little bit.  Like I have mentioned, these guys really
want to get good reliable systems out there and truly UNDERSTAND what's
going on with the systems to give the user a good, reliable product.  Again,
I'm sure the other battery guys are doing similar things--I just happened to
get together with these guys after working with them on some indoor issues.
I DO like their approach.

Richard


Congratulations on
> your placing third with a new electric design and thank you very much for
> your summary and all your feedback! We truly appreciate your
> partnership.    Regards,Greg Covey Director of Sales and
> Promotions, FMA
> : fred at fmadirect.com; Nathan at fmadirect.com;
> tim at fmadirect.com;<br>jamie at fmadirect.com; erics at fmadirect.com;
> GCOVEY at Rochester.rr.com;<br>payn1101 at bellsouth.net<br>Subject: > Hi guys,I
sent all three pair back today (2nd
> day-Thursday) for your analysis along with the flight sheets depicting
> their deterioration through the 89 flights.   In discussions with
> Nathan, one conclusion might be that the cells will have differing charge
> rates at different heat levels within the packs.  I suppose that would
> affect how each was charged and affect how they would run down.  I
> by-passed the DPMs as I was not getting through a pattern right before
> the contest this last weekend.  On three of the flights I barely
> made it to the end.  The controller did not completely shut me
> down--but the system acted like it was winding down to about 30% power
> and my last maneuvers looked  pretty ugly. The first and second
> place guys were flying the same airplanes--Temptations with
> 4c160DZs(I think)--huge patterns with gobs of speed.  I was flying
smaller, closer
> in with fairly quick movements to keep it in and ended up 3rd.  I needed
> every ounce of thrust I had.  Several people commented that it appeared
> Orland had more go.  So it would appear that over several flights, the
> batteries lose......something--capacity, balance--whatever.
> Hopefully the new chargers will overcome this. If everthing is
> OK--balanced--all cells pretty much equal, the heat build-up was less
> and they would run all the way through--but it appears if we get ANY
> deterioration--ANYWHERE--we have a problem.  I took the airplane over
> to Orland's today and we checked the amperage--It settled at about 65
> amps with his 4000s--so it would appear the rest of the system is
> operating OK.  I think we can safely assume for pattern, we NEED the 67
> amps or so that everyone with these systems is quoting.  If
> anything, I need more--but I can learn to live with this--I think.
> These systems are definitely NOT in the 160 class!(w/25-30% nitro)--but
> that's what we're competing against. My business will not allow
> time for a while to do large contests this year so I'm not going to worry
> too much about weight if you think we ought to be running the larger
> units.  I was hoping to get through at least one year with three
> sets--and again, maybe with the new chargers--we can. Please let me
> know the status and what you think. Fred, regarding props--we are
> running what has been successful for similar set-ups. Hacker doesn't want
> the motors turning more than 40,000 and we're turning close to that
> now--the downlines may be turning faster.  Which brings up another
> thought--If we have to stay in a smaller box, we will need airplanes
> similar to the Impact with more frontal and fatter wings and so slower so
> we can punch out of a slower downline on a central maneuver and get it
> centered.  Plus there are only so many props available.  APC does
> a pretty nice job. That is all for
> tonite. Richard 816-471-5505 w 800-279-7037 w 816-225-3801
> c 913-381-3519 h
>
>

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