Flying High With Electric Power! The Ampeer ON-LINE! August 1997 The Club Newsletter of the Electric Flyers Only, Inc AMA Charter 2354 Walled Lake, MI, USA Editor: Ken Myers Fly the Future - Fly Electric!

President:	Vice-President:	Secretary/Treasurer:	Board of Directors:	Board of Directors:
Ken Myers	Richard Utkan	Debbie McNeely	Keith Clark	Jeff Hauser
1911 Bradshaw Ct.	240 Cabinet	4733 Crows Nest Ct.	2140 E. Highland Rd.	18200 Rosetta
Walled Lake, MI 48390	Milford, MI 48381	Brighton, MI 48116	Howell, MI 48843	Eastpointe, MI 48021
(248) 669-8124	(248) 685-1705	(810) 220-2297	(517) 546-2462	(810) 772-2499
Mailed Ampeer subscriptions are $10 a year U.S. & Canada and $17 a year world wide. FREE on-line!		The Next Meeting: Date: Thursday, August 7, 1997 7:30 or ASAP - Rushton Road Flying Field, South Lyon, MI, between 8 & 9 Mile Roads

The June EFO Meeting

What's In This Issue?
Trexler Tire Info	May Meeting	How Fast Does It Fly?	The Modelair-Tech H-100 Belt Drive
Computer Use	Ratings from Sweden	E-Fly in Canada	Chip Rating
Hitec Radio Sources	Bill Grigg's Models Update	News from the Gulf States Area	Plane Ratings from Orville Shields
Central Indiana E-Fly	Dave Grife's Elextra	New Prop Talk Book	Simple on/off Switch
Upcoming Events	The Next Meeting

Care and Feeding of Trexler Balloon Tires from Tom Wilk, 301 W. Redwing St., Duluth, MN 55803-1711

A while back I mentioned problems with blowing up Trexler tires with your mouth. Tom wrote to say:
Regarding Trexler balloon tires filler tubes becoming stuck when filling by mouth, this can also happen when using an air pump. First off I suck up a bit of talc before filling the tires - this helps preventing the filler tubes from sticking.
If they are stuck, get your solding iron warmed up, using your pump tet a bit of air into the filler tube, then gently warm the tube with the soldering iron, but don't touch the tube! You will find that the tube will open and look as good as new. With the pump, suck up some talc and coat the fill tubes before refilling them.
Thanks for the tip Tom. km

One of the first questions asked of us by non-modelers! And one for which we seldom have any accurate answer, unless we have access to a friendly cop with a radar gun.
Actually, a lot of us, perhaps secretly, would like to know (just for grins) how fast our planes DO fly. Aside from that radar gun, there are ways to find out; the most obvious is to set up a timed run over a known distance, but that's a lot of trouble.
Without too much trouble, though, we can get a pretty good estimate by knowing our engine RPM and the pitch of our prop. Naturally we can tach the RPM on the deck, but knowing how much extra RPM we pick up in the air is part of the estimating process. It will all depend on your engine, the prop, and how slick your airplane is. If you assume you'll gain 1000 RPM, 2000 if your plane is pretty fast, that will put you in the ballpark.
Let's take an example: a relatively medium-drag airplane, powered by a .40 which tachs a 10 x 6 prop at 13,000 RPM on the ground, and we'll assume 14,000 at speed. The 6" pitch means that at best (a perfect prop!) The plane will move 6" for every revolution that's half a foot. 14000 RPM is [14000/60=] 233 RPS (revs per second) multiply that by .5 feet per rev, and we get 116 feet per second. Converting to miles per hour (60 mph = 88 fps), we have 116 x 60/88 = 79 mph.
A similar, but slicker plane turns a 9 x 7 at 13500 RPM assuming 2000 RPM pick up at high speed, we get: 1550(3/60 = 258 RPS, x 7/12 ft./rev = 150 ft./sec. Convening to mph, 150 x 60/88 = 102 mph.
In the past, we would have taken off about 10% for prop slippage at this point, after all, no prop can be perfect. But use of in-fight data systems has shown that top speeds are closer to the calculated figures than initially thought. This is because most props, using cambered airfoils, still have a positive angle of attack, and thus develop thrust, at their nominal pitch speed. Thus, a 7" pitch prop may have to go up to a 7-1/2 or 8 inches per rev before thrust falls to zero.
Note that the internal timing of most sport engines is such that they don't produce much usable power above 16-17 thousand RPM. So, beware of claims of well over 100 mph with a non-racing plane, unpiped sport engine, and a sport prop! Perhaps possible-but highly unlikely!

MODELAIR-TECH P.O. BOX 1467 Lake Grove, NY 11755-0898 Phone & FAX (516) 981-0372 Send E-mail to THunt95147@aol.com

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Computer Use

Many of you are already using computers to help you design and power electric models. They area also helping you gather information on electric flight. For those of you who have not used a PC, I can't urge you enough to try it. Many of you are retired or on fixed incomes, and I understand this is a problem, but many of you also have sons and daughters who have two or more PC's and some they may not be using. Why don't you suggest that you'd like to learn a bit more about computers to them, and see what they do. You just might end up with a useful tool!
Be sure that it at least a 486 with Windows and you can run ElectriCalc, and by investing in a modem, you'll be able to keep abreast of the latest developments via the World Wide Web. You won't regret it.
To get you going, here's a list of WEB sites you might like to visit: (don't worry about the funny looking http:// stuff, it is just an "address", and that's all you need to get there and start looking and learning)
members.aol.com/KMyersEFO/
web2.airmail.net/warner1/deaf/index.htm
www.adobe.com/acrobat
www.aveox.com
www.ezonemag.com
www.geocities.com/CapeCanaveral/Lab/1879/
www.iquest.net/~weaverr
www.nasm.edu/NASMDOCS/discinfo.htm
www.netads.com/com/cabdesigns/
www.netaxs.com/~mhmyers/vfss.html
www.ov-1.com
www.unbeatenpath.com
www.vipermodels.com
www.wpafb.af.mil/museum/modern_flight/mf48.htm
www2.ari.net/home/waco/wwwhome.html
wwwcommunique.net/~lakeside/perret.html
www.gatewayelex.com/kits2.htm
By connecting to the EFO site, you'll also get even more places to visit all over the world.
You might like to try AOL (America On Line) first, since it will give you easy, but slow, access to the World Wide Web, while holding your hand. There is also an electric flight forum right on AOL run by Bob Strought. He "hosts meetings" every Wednesday evening on AOL.

Hi Ken,
My name is Stefan Tholin. I live in Vara in southern Sweden. I would like to thank you for providing me and my fellow e-fliers with lots of information.
I have a couple of plane ratings here which you can use if you wish. The descriptions I sent are pretty detailed so delete as you please. Please ask if there are unclear things. I write in Swedish with English words! ;-)
You will find more info about my planes here: www.geocities.com/CapeCanaveral/Lab/3766/stmoden.htm
First,

HLG Midway Gnome *** (3) Span 60", Area 375 sq in, 23 oz, 2 channels, Sp400 7.2V or mabuchi 380 (don't know rating), titan 2.6 gear, Falco carbon fiber folder 11.5 x 7, 7 x 500AR, Jeti 30 ESC with BEC, 2 x HITEC 101. Difficult to get all the stuff into such a small plane. 10 - 11 minutes climb and glide flying.

Same plane but different power HLG Midway Gnome *** (3 - 3.5 slightly better i.e.) Span 60", Area 375 sq in, 23 oz, 2 channels, Sp400 7.2V, Graupner 6x3 folder, 7 x 500AR, Robbe RSC 210 (on/off) with BEC, 2 x HITEC 101. Still difficult to get all the stuff into such a small plane. 9 - 10 minutes climb and glide flying. Why do I believe this one is better? Thermals better and the trim changes when climbing are less pronounced. The 11.5x7 prop blades are bigger than the elevator!

SKYWARD 40 ARF **** (4)

I removed the nose gear and placed the main gear a little bit further forward. I placed a small nylon skid under the tail as protection. The rudder and elevator servo was placed behind the rear former. This gave me more room to adjust the cg by moving the batteries around. I fastened the receiver and the speed controller on the side with Velcro. The receiver battery and the motor batteries ( 2x7 SANYO SCRC in series) are fastened on the floor with Velcro too.

The motor is bolted to a plywood former which is screwed to the engine bearers. The rear end of the motor is reaching into a cut out in the firewall. Cooling air is let in through a hole in the firewall and is let out behind the wing.

Hi, Ken:
The EMFSO fun fly held at the Oakville Model Flying Club field this past Saturday (May 24) was quite successful. We had 22 pilots register, which while a modest showing, is nevertheless encouraging for a first effort.
More importantly, these pilots brought many nice aircraft including a 1/4 scale cub (lovely, graceful flyer), a non-flying (no water) six engine Dornier flying boat, numerous powered gliders, some of which were easily getting 30-35 minute flight times, some pretty biplanes including Rob Pike's Libery Sport which has been getting so much attention in the E Zone lately about the right prop to use, as well as everything from WWI Camels to WWII Mustangs.
A number of prominent non-electric members of the Oakville Club attended and were impressed by the performance of our electric planes. In a club which is so overwhelmingly non-electric, this is encouraging. We hope to make this an annual event.
Your assistance in spreading the word about the event is most appreciated.

Cheers, Walt
(Sounds like a great time was had by all. Annual event sounds good! Go for it! km)

The aircraft is the Chip, Graupner Speed 600BB 8.4, Graupner 8x4.5 folder, 2 S148 servos (ailerons and elevator), 7x1400 SCR, Astro 215 ESC. It is an aileron version of the UHU, but I understand this kit is no longer available in the USA. If you see one for sale, buy it! It is an excellent performer, loves to fly fast and grooves well. The motor and prop used are ideal for this plane, decent power and a long motor run. Battery swapping is easy through the removable canopy. The wing is unusual with the sheeting acting as the spars, it took some time to build. Ailerons more for banking than for fast rolls. Looks great when finished with white Ultracote and the supplied decals as shown on the plans. Rating: ****

Hi Ken,

I really appreciate your feedback. (We had been discussing what he wanted and my experience - good - with my Focus 4. km) In fact, I just called Hobby Horse in Madison, WI and ordered a Hitec Prism 7x with the Spectra frequency module. I talked to a guy there named Jim, and he had no problems swapping the four standard servos, that came with the radio, with four Hitec micro HS-80's. He just subtracted the price of the standard servos and added the price of the micro servos to the total. He also swapped the 8 channel receiver with the lighter micro 535 (I also had them swap the 650mAh receiver battery pack with a 270mAh one)! They have great prices and are very flexible. I'll be receiving the flight system in a couple of days. This beats the heck out of being forced to buy servos etc., that I may never use. You might want to pass this on to fellow electric flight enthusiasts.

As always, thanks for the info.,
Jim Yuzwalk

We've teamed up the Hitec RCD to bring you a micro radio system that only includes the items you really need. Not those you don't. The system includes the Flash 5 transmitter, Micro 535 five channel receiver, two HS-80 Micro servos with accessories, a system charger, switch harness and aileron extension. You won't get a full size receiver, full size servos or a full size receiver battery pack. For the first time, the box will be empty when you install this new radio system in your new Electric aircraft or sailplane.

• 2 Model Memory
• Model Copy Function
• Rudder/Aileron, Elevon, and V-Tail Mixing
• Dual Rate Ailerons and Elevator
• Digital Electronic Trims
• End Point Adjustment
• Total Volume Control
• Servo reversing
• Exponential Rates
• Trim Memory and Reset
• Timer and Low Battery Alarm
• Trainer Function

Also note that Larry's finally on line! SR is MORE THAN BATTERIES, they are a full line; motors, radios, planes, etc., supplier. SR's site is hosted on Steve Anthony's Hangtimes.Com site, you can go directly to SR at http://www.hangtimes.com/vendor1.htm

SR Batteries, Box 287, Bellport, NY 11712 516-286-0079 or email at: 74167.751@compuserve.com

By the time you read this, Bill's kits should be laser cut. He's carrying many more items, including several exciting planes designed by Don Belfort. He is also supplying batteries for S400 models, as well as the FMA receivers and servos. Send for his catalog or visit him on line at: http://ourworld.compuserve.com/homepages/griggsbill

Ken, I thought you might want to see some of my electric planes. The first one is a Tom Hunt Mega-Watt as a low winger. It has an Astro 40 with a 3:1 MAT (Modelair-Tech) belt drive on 24 1700 SCRC cells. It weighs 8 lb.12 oz., has an 80 in. span and 1300 sq.in. of wing area. It also has flaps. It is covered in orange and white MonokoteTM. I call it GIGA-WATT... It flies very well. With the flaps down it slows down to a crawl with no tip stalling. It loops tight from level flight and gets off in about 25 feet...Tom says the plans should be available by now.

The other picture is my design for the All-Up Last-down event. It has a 120 in. span and about 1100 sq.in. of wing area. It weighs about 4 lbs. (depending on batteries). It presently has a speed 600 12v motor on 4 6cell 1400AE packs through a series parallel switch (John McCullogh design) and a FX35D speed Controller (it keeps my receiver pack charged in flight + minute rpm adj).The prop is a 20x10 Rasa. I've gotten 45 minutes continous motor run so far, but I have to do better to beat the big guns. I sure would like to see you in October at the Gulf States Fly-in.

Ken,
I haven't been around for a while but I have flown a little. I thought I would add to the ratings if you would like.
So far this year I have flown a couple new planes.
Hobby Lobby PS 78, Astro 05G, 7x1500, 11x7 prop, 58 oz. *** I like the looks and the way it glides but it will tip stall very easily. I think it could use a little more dihedral because it hunts and it doesn't groove like I think it could.
Ted Davey (I think) Flybaby, included motor, 8x4 and 7x6, 7x1500, 43 oz. no *'s We have tried to fly it twice and all I get is a fast, underpower landing. We may try to install another motor and try it again.
I have also been flying my Seniorita with a new set of RC2000 cells and I am very happy. I get about a 15 minute flight with a mixture of whatever I want as long as I practice a little power management.
One more thing, last night I charged 2 sets of batteries ( 3 7-cell packs at once) for the Astro Hog. I use an Astro 112D charger on a lawn tractor battery. During the 3rd set of batteries the LCD window on the charger went blank and the charger it self was very warm. I opened up the charger and found a burned up transistor ( one of the power transistors that are heatsinked to the front panel). Have you heard of this happening? I will send it in but thought I would ask if anyone knows what I did wrong.
Love the Seniorita,
Orville
(According to what I've heard, Astro Flight Chargers will continue to try and draw from a low source battery and something usually gives. My "guess" is that it was a low source battery that was your problem. Charging 3 physical packs that are identical in amp hours and manufacturer should not have been the problem. Many people use 3 physical packs to make up a 21 cell pack, etc. Since they were run as a 7 cell pack and 14 cell pack, I assume from you saying they were 2 sets, they probably weren't discharged exactly the same, but I still believe the problem was the low voltage on the source battery. What is your experience? km)

Ralph Weaver, CD, and the Madison County RC Flyers put on their first electric fly-in on May 24 near Franton, IN. I'm not sure how Ralph did it, but he managed the best weather of the new flying season. It was a bright sunny day with low winds. Perfect! (Unfortunately, the next two days didn't prove as good for the folks trying to run the Indy 500!)
Ralph and the MCRCF are to be congratulated on a well run and well attended meet. Besides all of the "open" flying, there was a Speed 400 race, LMR for Speed 400, Class A, and Class B, and an All Up, Last Down. Lots of action for everyone.
Ralph and his workers provided great transmitter impound support, as well as running a well stocked concession stand! All of the hard work in organizing and running this meet paid off in a well received day.
My day started at 5:00 A.M. with the drive down. I arrived in plenty of time to hook up with Dave Grife, Clay Howe and Keith Shaw before the meet "officially" began.
The day ended with the passing out of the awards and the donations from great manufacturer support. There were lots of goodies for everyone. Even though I didn't get one of the "biggies", I was really happy with the set of Dimwatt plans and the New Creations catalog. I really needed a new catalog!
Great day. Hopefully they will do it again next year, and we'll see you there.
For those of you who can get to the Internet, I've put a slide show of this day in the on-line version of this issue. To view the slide show, visit http://members.aol.com/ampaug97.htm

An early morning walk down the flight line.

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Dave Grife's 27% Extra

At the Madison County R/C Electric Fly In, Dave Grife gave me the following info on his 27% Extra 300S. It is based on Midwest Plans. He redrew the fuselage to use a truss structure, mostly 1/4" square balsa with some spruce longerons. The turtle deck is 1/64" ply, as well as the wing doubler area inside the fuselage. He used the Midwest airfoil, except he sheeted with 1/16" balsa. The tail is truss sticks. Power is the Sport Astro Flight geared 60 with the standard gearing. He uses 33 Sanyo RC2000's. The prop is an 18x8-14 turning at 5700 RPM. The controller is an Astro Flight 204. The static amp draw is 27 amps. While the aerobatic flight duration is 6.5 minutes. It has Dave Brown 3" lite wheels, a R/C America composite landing gear, FiberGlass Master cowl and wheel pants and Midwest canopy. It weighs 13 pounds. He noted that he's going to be adding a high torque servo to the rudder. There's been no problem so far, but he just wants to be safe. For more information on this great plane you can send mail to Dave at: Dave Grife 471 Morse St. Coldwater, MI 49036

Fellow Electric Flyer, I've just authored a new 96 page book entitled PROP TALK. In the book, in a dialogue between two modelers, I've discussed simply how model aircraft propellers work and how to predict propeller performance based on diameter, design, RPM, and air density. The dialogue explores propeller performance for commonly used propeller designs, the results of seven specific experiments with propellers, and the application of these experimental results to understanding and improving electric powered flight system performance. I've included in PROP TALK the description of a method to select a propeller best matching the power system motor/gear box/battery combination to provide an optimum balance of launch or takeoff thrust and flight duration for an electric powered sailplane or sport model.

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The June EFO Meeting

The June EFO meeting was held at Ken's house. There were a number of things discussed including a "possible problem" Jack Lemon has found with Sanyo 1700SCRC batteries and their ability to hold their capacity over time. Jack is going to talk to Keith about this, and I'll let you know more about it when we learn more. Have any of you noticed deminished capacity with Sanyo 1700's over time? Remember this is not a finding - we are just looking into it - DON'T PASS THIS ON AS SOME KIND OF RUMOR. We just want to know why Jack's numbers came out like they did. Since June was the 40th anniversary of the Radio Queen, the first recorded successful electric R/C plane, Ken shared some information about this aircraft featured in Ian Peacock's book Introduction to Electric Flight. According to the book, the first recorded successful R/C electric flight was on June 30, 1957. It was built and flown by Col. H.J. Taplin and had a government surplus Emerson motor and Venner silver-zinc accumulators for power. It used a "bang-bang" clockwork escapment for rudder control. The picture is from the book. Ken also showed an easy way to test whether a "can" motor has neutral or advanced timing. A new Astro Flight Super Box was added to Richard Utkan's AF40G, with the pinion removal and replacing being demonstrated and participated in by the members. Ken also showed off his new MaxCim with hydraheaded controller plugs. (Think about that one!) Good meeting.

Next Meeting: Thursday, August 7, 1997, 7:30 or ASAP - Rushton Road Flying Field, South Lyon, MI, between 8 & 9 Mile Roads

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/