TwinStar and Blue Foamie Ratings
From: George Scrimshaw viking@redshift.com
TwinStar: Highly recommended. **** (4 stars)
A nice, easily assembled foam twin motor flyer with two S400s (supplied) and props
(Gunther--they look like toys but their ability is nothing short of remarkable). Built stock, but with the Multiplex duo ESC to
run both motors. With a 7 cell pack it flies well and is mildly aerobatic; with an 8 cell pack it comes alive. Easily hand launched,
very durable (on one launch by a club member, he launched straight UP--it got up about 15 feet and, of course, came straight
down. Damage was a slightly dented nose and a broken half stabilizer, which was easily repaired. Easy to fly, even in somewhat
windy conditions--8-10 knot winds. Easy to land.
Blue Foamie (Pat Mattes): Highly recommended. FUN!!! **** (4 stars).
Inexpensive. Simple boxy fuselage and flat bottom wing. Unusual assembly--wing
is taped together, motor (s400) is squeezed into a trough in the fuselage and taped in place. Behind it are the ESC, battery,
receiver and two servos on top of the rear fuselage with rudder and elevator of sheet balsa. All hinging is with strapping tape.
Everything works better than you would imagine. A great flying machine! I used a Gunther prop--the small white press-on
type--and am constantly amazed at how well it works!
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EPP Focke Wulf
The photo of the S&B EPP Focke Wulf that was mentioned in the January
2000 issue. See that issue for details and availability at Markys Hobby Shop.
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Futaba Service Center New Location
Futaba Service Center is now up and running at its new Illinois location at:
Futaba Service Center
1610 Interstate Drive
Champaign, IL 61822
Product Support Hotline: 1-800-262-7885
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February 11, 12, 13 A Celebration of Electric Flight
SILENT ELECTRIC FLYERS of SAN DIEGO announces the third annual
MID WINTER ELECTRICS
Flying events included: Old Timer Pylon Racing, Sp400 F5B Racing, Sp400 Pylon Racing,
Dragonfly Pylon Racing, LMR Glider Toss, Scale Flight and Exhibition
Friday, February 11, 2000 evening there will an Electric Flight Symposium at the San Diego
AeroSpace Museum.
Saturday, February 12, 2000 evening a Mexican Feast a get-together at Marina Village, less
than a mile from the flying site.
And don’t forget:
Dealer Booths, Event Tee-shirts for $12, Great Raffle
Come fly with us and visit LEGGOLAND, just 45 minutes north on
Interstate-5. Don’t forget the San Diego Zoo and the Wild Animal Park,
the AeroSpace Museum, and the world famous beaches along with Mission
Bay Park. Our flight site is within walking distance of Sea World Park.
Visit our web site a sefds.org for details or contact, Don
Wemple, at DonK126@aol.com or call (619) 469-5566.
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Gordy Cells
From: Gordy Stahl GordySoar@aol.com |
I have plenty of Gordy Cells right now, just for your information :-) |
Gordy Stahl
9303 LeBeau Ct
Louisville Ky 40299
502-491- 5001 |
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A Happy New E-flier
From: Armand Francoeur email: afran@ix.netcom.com
Hi Ken,
I have several flights on the Sig LT40 using the Astro Flight 40G that you
recommended. I am using 20 Panasonic 3000mAh cells and getting 15-20 min flights. You are right -- no one believes it is not an
internal combustion powered aircraft!!
I am sold on electrics and in the process of selling my fleet of glow planes. Long
live EP!
Thanks for the help, Armand
Glad I could be of help, and I’m very pleased that you are so satisfied.
KM
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Electric History
From: Dale Wilde Wildenm@cs.com
Hi Ken,
I thought you might be interested in this bit of history. I was looking through
some of my old model magazines and found this ad for electric flight. It's from Air Trails, 1960 Annual. It looks just like some of
the schoolyard stuff sold today at more than an order of magnitude in cost.
Dale
I trimmed part of the page. The supplier was Associated Hobby Mfrs.,
Inc., Dept. AT 60, 1240 Gilbert Rd., Meadowbrook, PA. I believe that it is same AHM that may still be around. If anyone
else has other ads or any knowledge about our e-past, please share that information with us all. This kind of
information will go well with the “That Was Then - This is Now” series of articles to be presented here in the Ampeer.
KM.
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N.E. ELECTRIC TECH FAIR
Via Silents Please, Dec. 1999
Editor: Frank Dellamura email: fdellamura@aol.com
Tom Hunt updated the news regarding the proposed Northeast Electric Aircraft
Technology Fair event (replacing the KRC event [as a major east coast event KM]).
Tom reported that initial responses from the KRC club leader was not to share
their data base with the new organizers, but the club (later) voted to provide the data.
Joe Becker, organizer of the War bird Meet, found a suitable area that might be
available for event in Goshen, New York. The owner of a resort in Goshen expressed interest.
Tom reported that Bill Steincamp (Allentown airport manager) is confident that the
airport authority will either control the airport or receive the property from the town. A site decision may be made before the
WRAM Show in February.
And from a Personal Note from Bob Aberle
On a positive note Tom Hunt and I, along with the help of Joe Beshar have located
a wonderful flying site in central New York Sate to be used as a replacement for the traditional KRC Show. It will be held the
same time next year, like Sept. 22, 23 & 24, 2000. The place is a campground called Peaceful Valley at Downsville, NY, Exit 90
off RT-17. It is about 60 miles sought of Binghamton, NY. The field is about equal in size to Allentown and about three times as
big as the old Buc-Le field in Quakertown. Best of all it is a campground with bathrooms and showers on both ends of the field.
The grass area has no rocks at all and will be cut like a golf fairway. We are keeping out fingers crossed. Boy if you could only
sneak out of school for a few days!
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Batteries---Watts UP?
by Carl Schwab
via Silents Please, Silent Electric Flyers of Long Island newsletter, Sept. 1999
INTRODUCTION
E-powered flight is entering exciting times. New (not really new, but enjoying
exposure) battery technologies promise much better performance.
Where we are now?
What we have now are Nicad, NiMH (nickel metal hydride), Li-ion (lithium ion),
Li-M (lith-ium metal), shortly Li-Polymer and eventually others. We are all familiar with Nicad technology, which now has been
around with, first the sintered and later the porous anode, for approximately 45 years. The technology is VERY mature and, to
date, is still king of the hill for extreme discharge rates. Unfortunately the hobby group is about the only one interest dimensions
- Nickel-based technologies produce cells that average about 1.2 volts per cell, while being discharged. This has made the
idea of measuring capacity in mAh (milliamp hours) useful.
Lithium Cells
- When you go to Lithium, it’s a different story. MAh is misleading and confusing. So, the Li battery people use watt-hours or
whr for short. I suspect you will see RC suppliers turning to this terminology as the lithium-based battery use increases.
Example: Comparing a AA Ni cell rated at 800 mAh to a AA Li cell rated at 800 mAh, shows that they are
nowhere near equal in the whr de-partment. In the first case 1.2 x .8 = .96 whr while in the second case it is 3.0 x .8 = 2.4 whr.
Clearly the Li cell has about 2.5 times the Watt-Hour capacity of the Ni cell (Due to the higher voltage of the Li cell.
GMM.)
Li-ion is more expensive than NiMH, BUT has a better performance in the number of "charge-discharge cycles
without capacity loss" than any of the nickel technologies. Also, better shelf life (charged), and no memory effect (only Cd
cells have that). The ability to take many charge-discharge cycles without reduced capa-city is a major advantage of Li-ion:
That’s why it’s popular in the computer and PCS markets. It’s also attracting considerable attention in the full size E-car market.
In the battery business you see the terms "whrs per liter" (whr/l), and "whrs per kilo-gram" (whrlkg)
used to assess the potential of various battery technologies. When you com-pare the whr/kg for any Li cell to any Ni cell the Li
cell wins, because Li is lighter than Ni.
(When I went to buy some Li cells, I was told that the manufacturers are holding back on retail sales. When I
went on the Internet, I found out why: Lithium is poison and has bad interactions with many heart medicines. GMM)
Nickel-Metal Hydride cells
We have skipped over NiMH, which should not be taken so lightly. The
rechargeable battery market is dominated by hand-tools, computers and personal devices such as cell phones and camcorders.
LAST, but not least, are full size E-cars. Notice that E-power hob-bies aren’t even mentioned.
The hand-tool, computer and PCS (personal communication services) look for best battery performance based upon 1 hour
use per charge. E-flight is interested in 6 to 12 minutes. So, let’s introduce a term that seems familiar "C".
3. "C" refers to cell capacity BUT it also refers to the constant discharge current that will take a NiMH cell down to 1.0
VDC in 1 hour. (I was able to buy a NiMH pack and get the English translation Engineering Manual. GMM)
Let’s say we want an 8 minute motor run and we know that our motor/propeller draws 8 amps from six NiCds. We can
estimate the "C" rating needed for 6 LiMH cells by calculating 8amps x 8/60 hrs=8000ma x .133hr = 1067 mAh.
Discharge rate will be 8000/1067 =7.5C. From the charts: Capacity diminishes about 5% per multiple of C, to 3C. We’re already
off the chart, but we can approximate that we need six
LiMH cells rated about 7.5x5%=38% higher.
1067 x 1.38= 1472 mAh to run 8 min. at 8 amps.
Pick the next larger cell, “C” = 1500 mAh.
(High discharge currents reduce cell capacity by losing energy to heating the cell.
(whr stored - whr heat = whr avail)).
Hand-tools, computers, camcorders and PCS are nominally C applications. For us
to extend that to 5C and 10C is, literally, a stretch, BUT Nicads have accommodated us. NiMH is trying to accommodate us, and
will get it done, in spades (eventually). NiMH has intrinsic advan-tage over Nicad in the whr/l and whr/kg categories AND is
toxin free (no cadmium). NiMH cells have been around a while and will become more plentiful, eventually replacing Nicad in the
hand tool market (I think).
E-Cars
The full size E-car market has some simil-arities to E-power flight. Car makers are
interested in FAST charge-discharge AND repeated charge-discharge cycles.
The braking system of an E-car is called "regenerative,"
meaning that the momentum of the car spins the motor as a generator, to recharge the battery (at very high currents).
Acceleration is provided by battery power, again requiring high currents.
E-car engineers are not interested in 500 cycle life. They want literally thousands of charge-discharge cycles. They are looking
for 35,000 mile battery life.
E-car manufacturers are investing heavily in Lithum technology and have had some
success with Nickel Metal Hydrides, which makes me believe that, for our purposes, NiMH will eventually displace Nicad.
It is an EXCITING time! Carl Schwab
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Corrections and Additions to Part 1 of "Power Systems for Electric Aircraft"
Ignore the motor data at the end of Part 1, Ampeer,
January 2000. New information appears in this
issue. After checking with Keith, DO NOT even think about running the Astro Flight brushless 020 with 10 cells and using the
BEC.
The Astro Flight 215D/217 data should not have been lumped together in the
R/C components table. I weighed the 215D with power wires and radio connector, as supplied. It is 0.6 ounces. I reweighed
the Astro Flight 217D with power wires and radio receiver connector, as supplied. It weighed 1 ounce. Anderson Power
Poles/Sermos connectors weigh 0.1 ounce per pair. Please add that data to your table.
All tables are subject to updates and can viewed and printed from the EFO
website at http://members.aol.com/KMyersEFO. If you do not have WWW access, please send me a SASE, and I will send you
the most recent table updates.
All tables will be updated as time permits and information changes.
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The January EFO Meeting
The meeting was held at Ken’s house. There were many members and guests,
and before the meeting was over several new members. Welcome Rick, Bob, and Wally.
Ken had his new SR Batteries X-250 laid out for all to inspect. There were
many positive comments on the quality of the kit, and everyone was very surprised to see the high quality accessories included in
the kit. It will save a lot of wasted trips to the hobby shop to get what was forgotten. Hopefully there will be more next month on
this very nice kit, as Ken gets into the building.
Election of officers proceeded in the usual way, with the current officers
retaining their positions. Thanks for the vote of confidence.
It was decided not to pursue the use of the Rushton Rd. field this year, as we
could not sub-let it from Midwest R/C Society, since they did not renew their option. We will be holding summer meetings at
various fields in the area. Watch carefully for dates and times, as they will vary thought out the spring, summer and fall months.
We also which to continue to have a close association with MISS (Michigan International Soaring Society).
The year 2000 dues are due. Please send them to Ken.
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Power Systems for
Electrically Powered Models
by Ken Myers, January 2000 email: KMyersEFO@aol.com
The article is not in this issue, as it will remain online
after this issue is taken down in a year. Click the title of the article to read it.
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The Mid-America Electric Flies report is not actually in this
issue. To read the report click here. Use the back button
of your browser to return to this issue.
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To Reach Ken Myers, you can land mail to the address at the top of the page. My E-mail
address is:
KMyersEFO@aol.com
EFO WEBsite: http://members.aol.com/KMyersEFO/
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