Andy Woitowicz <  > recently developed a safe way of charging 120 mAh NiMH battery packs with the Ace "Super Smart Charge".

The problem is that the SSC has a constant-current output of 508 mA. That's far too much for 120 mAh receiver packs! Andy tried various ways to reduce the current to the battery. Most didn't work well, and aren't worth describing.

What DOES work is a 5-watt, 6-volt, 5% tolerance Zener diode installed as a shunt across the battery terminals during the Super Smart Charge operation.

"Regular diodes" act like one-way gates. They let "traffic" pass in one direction only. A Zener diode is like a 2-way gate, but strongly spring-loaded in one direction, so that "traffic" can easily pass one way, but has to push hard against the gate to get through in the other direction. And not all the "traffic" DOES get through...

When SSC charging a 120 mAh NiMH pack with the 6V Zener shunted across it, the voltage from the charger output is high enough to "overcome the gate spring". About half the charge current passes through the Zener, which then acts as a resistor. It dissipates the current that passes through it into heat. The battery pack receives only about 250 mA, which is safe.

Then, when "peak charging" is complete, the SSC goes into "maintenance mode". In that, it shuts off -- but sends a brief pulse of full-strength charging current about every 60 seconds.

The battery doesn't discharge through the Zener diode shunt during the one-minute "idle pulses", because its output voltage isn't high enough to "overcome the spring in the gate".

Andy has submitted an article on this technique to Flying Models, and Frank Fanelli has graciously given permission for this short summary to be published here in SMALLnet. Thanks, Frank! [JW]

Tony Aluknavich <  > reports:

The new kit will have the same construction techniques as the X250 from the same company. I got a preview from Larry Sribnick of SR (see the link below). The kit should be available in 3 weeks or so. There is also a write-up in Model Aviation, on pages 94 - 95.

< http://www.srbatteries.com/cutie.htm >

Tony Aluknavich The Woodlands, Texas

Howell H. Gwin <  > contributed:

Omigosh!! The Cloud Tramp still lives!!

I built almost one-a-year from the time the plans appeared (in Flying Models? 1950's?) until I left school (1962). I still have the hand-carved prop and balsa wheels I made for the first one. I built them of 1/32, 1/16, built-up construction, etc. and never had one that wouldn't fly just great. I even lost 3 or 4 (CRS): one built-up and the others sheet.

Wow. Thanks for mentioning it. My RASCAL just got pushed to the back of the board. Howell

Paul Lund <  > inquires:

The little Norvels come with the muffler installed with the exhaust pointing forward. Is it okay to run them that way? Or is the resultant back pressure a problem? I've got a little control-liner that will require some cowling modifications with the exhaust rearward, but forward would be no problem. Just curious.

Thanks. Paul Lund

Dave Hill <  > wrote:

I had my first experience flying my electric Lite Stick at the local soccer field a few blocks from my home. Several kids rode by on bikes and yelled out that it was "neat". I made 3 flights before the motor/gearbox/prop assembly parted company from the airframe. I thought I had only lost a prop, but the airframe was VERY tail heavy, and was a handful to fly.

I managed to land it with no damage, and spent the next 30 minutes looking for the motor/gearbox/prop. I found it, too.

There was no damage. Before the next flight, I will drill a hole through the gearbox and stick fuselage, and pin the motor in place. Great fun! Regards, Dave Hill

Al Lidberg <  > contributed:

A friend sent along a Xerox of part of a book: "Model Airplanes, Building and Flying", by Joseph S. Ott, from 1932 -- which includes a chapter with the Fokker Triplane, matching the plan I mentioned about a week ago. The plan is presented at about 4" span, but an accompanying table shows that plans were also available at 15", 30" and 45".

Strangely enough, the only propeller-carving diagram is for a 10". Anyhow -- 1932 is a lot earlier than I thought for this model design. AL

Ed Toner <  > wrote:

There's an XL Firebird hanging in the local hobby shop. It looks like a nice way for a beginner in R/C to go. Any comments?

Ed Toner

Ian Campbell <  >, from Weymouth, Dorset, England -- and Michael Rolls <  > notified us that although Aeromodeller has ceased as a separate magazine, it has been incorporated in Aviation Modeller International.

Michael reports: Existing subscribers to Aeromodeller are being offered a choice of having AMI with AM incorporated, or the refund of the balance of their subscription.

The first combined issue came out a few days back -- so far, so good -- (what other UK magazine would have articles on F/F electric contest models but Aeromodeller?)

Hopefully it will retain its identity within the AMI mag -- although other "incorporations" in the past have rapidly become disappearances. Only time will tell.

Neville Mines asked about plans for the KeilKraft Scout. A little while back, Peter Martin had the plan available - can't promise he still has it, but it could be worth a try if nothing nearer home comes to light. Peter's address is:
16, Ashfield Court,
Middleton Hall Road,
King's Norton,
Birmingham
B30 1AF United Kingdom

"Someone recently enquired about methods of sealing strap-on mufflers to the exhaust port..." I missed the original query -- another alternative is to use plumbers' Teflon tape as a gasket -- no need to cut the hole for the exhaust accurately -- just a rough cut and the first time you fire up, the hot gases cut the opening to precise shape for you (of course you do have to trim the outside yourself!)

All the Best, Mike

Mike Woodhouse <  > sent in the same information about AeroModeller.

David Larkin <  > sent:

Concerning Neville Mines' search for the Scout, there is a Vintage Team Race group in England that should be able to help.

I think Model Flyer had a comprehensive article on this activity recently. I'll look and see if I can find an address. Failing that, the Scout was basically a modified Phantom trainer. Kits for this are still available, made by Amerang and distributed by Irvine and Flair. The Aeromodeller Annual for 1950 has an article on team racing with a side view of the Scout, from which it should be possible to develop a reasonable facsimile of the Scout....

Here's further (and newer) information on this model.

Contact <  > for the 'Scout' plans. Peter's website is < http://www.petesplans.com >.

Peter says: "I can do a copy of the plan plus the extra sheet which shows the Team Race conversion. No parts patterns, but there is probably enough information to enable it to be built. I should think this will be $4.50 including postage. If only I could get my hands on a Scout kit."

Best regards, Dave Larkin

<  > responds to Chris Rose's query about a good electric-powered R/C trainer:

My vote would be cast for the "Amptique", which is now being kitted by Spirit of Yesteryear. It was my first electric, 15 years ago, and still flies regularly today.

Simple construction and a good flyer when powered with a Speed 600 motor and a Master Airscrew 2.5:1 gearbox.

Jim Zare did an article on re-powering this aircraft in RCM about a year ago. He used a Speed 480 with a 4:1 box. I have redone mine to these parameters. It makes the airplane much lighter, and an even better flyer. Togflier

Augie Freda <  > adds:

To Chris Rose concerning the GP PT-Electric.

I built one, and have flown it several times. I did not build mine as a trainer, but it is a nice slow flyer, and would provide a good entry into powered flight. The only knock that I have heard about the PT-E is that it is underpowered with the supplied motor. I did not find it so. It is a forgiving plane with large dihedral, and is a really nice flyer. Enjoy it.

Augie Freda

Dave Segal <  > remarks:

The PT-Electric is a competent electric trainer, as it has enough wing area, and is simple to build. I built one a few years ago, but did not fly it, as it was intended for a club raffle.

Keith Shaw approved it in a 1994 article on electrics, but warned not to use any more than 1/4" washout. The Higley's "Entering Electrics" book says, "A good low-cost beginner's model".

I think the nose gear is dumb, so I built the plane as a tail- dragger (we have a grass field). It is also sometimes flown without any landing gear.

I don't know if you are knowledgeable about e-power, but you must commit to quality (read expensive) power gear to be successful. Avoid like the plague any gear sold for use in R/C cars. If you want me to expand on this point, let me know.

Keep it light -- use a BEC controller and small servos. If you want to improve performance, a geared motor will make a difference -- but it will certainly fly on the stock motor.

If you want a trainer that is a great floater, consider the Amptique. Shaw calls it "the most benign trainer ever designed." The only complaint I have about it is that the narrow fuselage cross-section makes the R/C system installation a little tight.

Good luck,
Dave Segal
Keystone RC Club
Philadelphia, Pennsylvania

Dereck Woodward <  > returns after WAY too lengthy a hiatus:

A little quiet of late, but still here ...

Understand the AeroModeller title has been bought by "Model Activity Press" (long-time Brits might spot the initials' other meaning. It's part of a long story ...).

From what I heard, it will be used as part of their "Aviation Modeller International" magazine, a broad-brush aeromodelling monthly, sort of a glossy FM. Interestingly enough, since a certain "gentleman" with the initials "DB" got sick of them not using his rules and left with his ball, Alec Gee - ex-Model & Allied Press (where else did those initials crop up?), Argus Specialist Pubs etc., from the year dot - and Ron Moulton, whom I cannot adequately introduce as I get stuck after 'my boyhood hero', have joined MAP as editorial staffers.

Chris Rose asked for advice on the Great Planes PT-E. Chris, I assume you want to stick around that size of model. The PT-E is a great little trainer, and can be a lot more agile with a hotter motor and wild control throws. It's an easy build, flies great. Has a good battery access hatch, so you don't have to take the model apart to 'refuel' -- an old electric problem with far too many models.

Downside is that the trike gear and little wheels make it something of a tarmac bird; fitting a taildragger means a major rebuild. The PT-E sticks you with the relatively inefficient direct drive/small prop too.

Hobby Hangar's "Electric Scout" is a great flier, though intended more as a three-channel sports model than a trainer, being very lightly built. Might not be a problem, as you can already fly. < http://www.hobbyhangar.com > is their place; they only sell direct. They also sell the excellent Pondside electric flying boat, which not only uses the same sort of power, it uses the same wing!

Look up "Spirit of Yesteryear" who do the excellent "Amptique" trainer and many OT R/C variants for around the 7 - 8 cell electric power bracket. These all make good loafing around models. The Amptique is a great flier, though you get to take the wing off to swap packs. Not too much hassle as it is only three channels.

Hope that helps, Dereck Woodward

Jim Simpson <  > relates with some glee:

At a swap meet here in Albuquerque last weekend, I found a brand- new-in-the-box, never-been-touched Speedee-Bilt P-40 kit.

I had to buy it.

Can't believe it is so small -- Speedee-Bilts seemed like pretty good-size planes when I was building them. Once won a contest (in Santa Fe) and first prize was a 15-minute ride in a brand new Cessna 195.

See why I'm a model builder ??

Bob Chiang <  > requests:

I am looking for suggestions for an electric aileron trainer to build. I'd prefer stick and tissue type construction for its light weight (and since I don't have foam cutting equipment).

I have a 6V Speed 400 motor with 2.3:1 gearing, a Kontronic speed controller, and 7-cell KR600AE battery packs for the power system.

I have a Hitec Focus III AM radio with the HS-55 servos. I am comfortable flying a rudder, elevator, throttle model in moderate winds, and want to learn to fly with ailerons, elevator and throttle.

Does anyone have experience with the Electric Kitten (Flying Models plan)? Could I decrease the dihedral add strip ailerons to this model? What would the appropriate dihedral, and aileron dimensions be for training purposes?

Thanks in advance for suggestions and comments.

Bob Chiang Ithaca, New York USA

Sam Brauer <  > is back with another of his detailed reports:

I thought I'd tell the gang about some experiences I've had with a little ducted fan jet I've been playing with. I, too, have been bitten with the jet bug; but I remembered your comments in Postings past that since ducted fans move small masses of air fast, rather than large masses of air slowly, ducted fan airplanes will be more efficient at higher speeds.

(It's effectively the difference between kinetic energy and momentum -- a good physics problem.) Thus, trying to keep a fan airplane hyperlight and slow would be problematic.

Nor did I want to try monkeying with getting a screaming engine running in such a constricted environment. I have enough trouble when I can actually reach my motors.

Not wishing to re-invent the wheel, I contacted Robert Wagoner at the Electric Jet Factory. He's quite accessible and eager to help. One of the things that I learned was that minimum sizes of motors tend to be dictated by batteries -- fans are on the edge and need all the amps that they can get.

I don't know how the new 500-720 nickel metal hydride cells stack up yet, but in practical terms, the smallest useful battery is an 8-cell 600 AE nicad pack. The smaller FF ducted fan stuff seems to have very little extra carrying capacity for servos, receivers etc. even with the new lightweight gear.

Once you lock into the 600 mAh nicad batteries, then the least expensive fan with the most thrust is the Turbo 400 that Electric Jet sells for about $40. This fan is based on the cheap Speed 400 6V motor.

Eventually I decided to buy an airplane to match up with the fan, so I would have a proven combination for the first time. I picked up the Flying Styro A-7. The kit is billed as an ARF, but there's plenty of work to do since you are going to have to do some bashing to get the fan in. I've written out a more detailed set of directions, which hopefully Robert W. will post on his web site -- what I worked from left a little to be desired.

Reviews of these Flying Styro kits have been inadequate. Based on what I've read on some of their other kits, I expected something of higher quality. Maybe I'm just not used to foam airplanes -- I much prefer working with balsa.

Anyhow, some of the major components of the ARF version of this kit come with the components painted and assembled. For whatever reason, the tops and bottoms of the right and left wing panels were glued together with a minimum of glue. This probably works OK for rubber, light electric FF, or display purposes. But this R/C airplane is going to weigh in at close to 3X the flying weight of the FF versions.

When I cut out the ailerons, the trailing edge of the wing disbonded, as did one aileron. Annoying, to say the least -- so I added some Titebond and RC-56 (either one worked OK). I don't think the molds are that well done either. The parts fit was rather poor and needed some clean-up work. This comment holds regardless of the intended application. So don't buy one of these kits if you expect to produce a museum quality airplane. (If you do, get ready to put lots of work in.)

Building this airplane reminded me somewhat of putting together a plastic display model.

Flying the airplane was a different matter though. I've only got a few flights on mine, but it is a trip. (Plus it's a real draw for kids -- I visited some of my friends with a bunch of airplanes, but what the kids (aged 4 and 8) wanted to see was the jet fly.)

Yes, the airplane can be hand-launched (that's the recommended method), but it does need a reasonably strong toss. Don't expect it to fly out of your hand -- and a little headwind is helpful.

The sound is not loud enough to be noxious or too high-pitched, but it definitely adds to the effect.

In the air, the A-7 looks very realistic. The airplane definitely doesn't have enough grunt to loop from level flight, but I haven't tried putting it in a long dive yet. It's clear that looping will take work. However, the airplane rolls readily. It's actually quite stable in pitch, but pretty sensitive in roll -- not surprising, given the long fuselage and the low-aspect-ratio wings.

Stalls should be avoided unless you have lots of altitude. The first time I went into a power-on stall, the nose pitched straight down and the airplane rolled. Clearly you must keep your speed up at low altitudes. (Isn't this the same advice they give full-scale jet jockeys?)

The flight speed of the jet is decent -- it's nowhere near as fast as my Twister, but a good chunk faster than my Cherokee. Translation -- a House of Balsa TD-powered aerobat will leave this thing in the dust -- no contest -- but you can fly the jet in a more restricted space -- keeping with the intent of SMALL.

It's not that hard to fly, as long as you don't let it get too slow close to the ground. I think if flies better than the Kyosho F-16 I saw, and that one was very well flown. I think there is more power reserve, and due to its smaller size, the A-7 looks like it is flying a bit faster -- i.e. more realistically.

Landings aren't bad either, but do keep some power handy. The jet skids in on its belly, so you want to have a nice grassy field. Given the relatively delicate construction, I'd be hesitant to add more power if it would entail more weight (and it would).

I don't think this airplane is going to have great longevity. It's relatively delicate and doesn't stall well.

The specifications: wing span 27" (but jet wingspan is misleading -- the airplane is much larger than a normal rubber ship or most other layouts of this size), Weight is 17 ounces. Power: Turbo 400, 8-cell 600 AE pack, EJF speed control, 2 HS 55 servos, and a GWS 4RP receiver which seems to be doing fine.

Flight times are relatively short. I haven't timed them, but this airplane does suck up a battery pack in a hurry. On the other hand, I've been pretty exhilarated flying the airplane, so I think the flights are long enough.

Overall, my thoughts are as follows. This jet is a ball to fly just for the sound and the appeal of the airplane when airborne. The kit is not wonderful, but it does work adequately to get you into the air with a relatively minimal cash outlay (comparable to any decent Speed 400 airplane, i.e. Twister or Jim Ryan warbird.)

In short, if you want a ducted fan airplane that looks like a full-scale airplane -- for a smaller cash outlay and better (I think) flight performance than the Kyosho stuff, check this one out. One of these days, I'm going to do an F-4 though -- and no more foam for me.

Sam Brauer Norwalk, Connecticut

Ron Fikes <  > sent in copies of some recent e-mail queries he's received:

Morris Lee
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Morris, I got mine at San Antonio Hobby: < http://sahobby.com > or try < http://batteriesamerica >.

Ron, The "Spot" looks like a winning design. Is there any way you could send me the plans?

Paul Penney

>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Paul, Plans for the my "Spot" are ready. These plans come with a copy of "MOOsquito" plans -- the building details are the same for both. "Spot" is just an enlargement of the "MOOsquito", but for use with "LiteStik" components. Look at some pictures at: < http://www.geocities.com/srfikes2001/Spot.html >.

The "MOOsquito/Spot" plans are $8.