Roy Clough <  > writes:

I've followed the biplane decalage-incidence comments with interest, waiting for somebody to bring up my take on it. Since nobody has, here goes: I relate incidence to thrust line.

That is, if both wings are an equal distance above and below the thrust line, then both wings have the same incidence. (Except as see below.) If the top wing is farther above the thrust line than the lower wing is below it, then I reduce the incidence in the upper wing (or increase incidence on the lower as the design indicates).

The object, of course, is that changes in power settings should not result in pitching nose up or nose down. It seems to me that incidence settings relate to thrust and drag. Like with old-time rubber-powered models, the higher the wing above the thrust line, the more "downthrust" required -- and low wing models used none, or in extreme cases, "upthrust" to balance the pull of the prop against the resistance of the wing.

It is my pet prejudice that for flat bottomed, or semi-symmetrical airfoil sections, about 1 or 2 degrees more incidence on the lower wing increases both longitudinal stability and stall recovery. For symmetrical stunt designs I'd try to keep the thrust line centered between zero incidence wings.

Roy C.

Mark Garvey <  > wrote:

Just a quick note. I am leaving on vacation for a week :-) but there seems to be no room for model airplanes, even SMALL ones :-( but it IS only a week!

Regarding the Sopwith triplane and other multiwing ships: Has anyone ever built a large copy of Bill Hannan's design/Sig produced "Uncle Sam" ? I have pondered doing this, but have not actually built one. (My building seems to be losing more and more ground lately!)

The rubber-powered version is a fine flyer. Indoors or out. A built-up-from-sticks biplane of about 10-inch span, with NO DIHEDRAL. Instead, it features "inter-wing curtains". It could easily be revised for electric or small diesel engines, I think.

I have often shown small people (5th grade or so and up) how to scratch build these little birds or "improve" the kit. (That is easy, simply use tissue paper instead of the supplied covering!)

But unfortunately I have not managed to take the time to overcome the problems of increasing the size to 30 inches and adding R/C. By the way, Hannan's books are an excellent source for "interesting" models! He has a love for obscure aircraft and his "Peanuts and Pistachios" books or "International Plans and 3- views" and "Models and Musings" (you've GOTTA read this one at least!) are all well worth the price! Sorry if I sound like a commercial. I admire Bill from afar, but have never met the man. I DO have a number of the books however.

Mark Garvey

Dave Larkin <  > submitted:

May I gently chide Tom Beveridge, of Scotland and Manitoba, whose sentiments, however, I applaud? The ED 2.49 was around in 1948 -- I have a couple of them in my collection. I think he is referring to the ED Mk III Racer 2.46, which was widely used in team racing; but it didn't appear until early 1951. A gorgeous engine which I used to race in Ireland and England in the mid 50s. It was like a McCoy 29 racing engine in appearance but had double exhaust stacks and circumferential porting. An engine with power and the best of manners, unbeatable until the Oliver Tiger appeared.

I was under the impression that I saw the first team race in the UK in April 1950 in Brighton, where it was won by Phil Smith with his Midget Mustang in the pouring rain. So I'm inclined to suspect that Tom is recalling a slightly later era.

Incidentally shrunken ED Racers have been available lately. Tomas Mejlik has an 0.049 version with ball races, and now VA has a 0.03 version (0.5cc) with a plain bearing. I missed out on the first shipment of the VAs, but hope to get some later.

Many of the early British R/C planes used ED Racers, and it was in production for a long time, eventually being available with a muffler and a crude plastic R/C carb.

Dave Larkin, Ottawa.

Malcolm Logan <  > also addresses Tom Beveridge:

Tom - I must have read of your achievement at "The Nats" in the Aeromodeller of the day. You're a lang way frae hame the noo ! Your "equipment question" is common to many, if not all, aspects of R/C and not just the SMALLnet -- which may not be the forum to provide you with the best answers to your question.

For example, you may wish to consider contacting both manufacturers, Hitec and Futaba, and also an authoritative independent source. All can be found on another forum -- RC Online, which does cover most aspects of R/C -- but not SMALL, which is of course a world unto itself ! And it's all free too !

I get there by typing "RC Online"; clicking the title page and then clicking "RC Forum". That gives you a menu of subjects, one of which is "Transmitter Talk", and is moderated by Don Edberg, who is an author on R/C subjects such as how to get the best from your computer radio. If you pose your questions wisely, you could well find that Mike Mayberry of Hitec and AnneMarie Cross of Hobbico (who now handle the sales and servicing of Futaba) will respond.

That will give you both sides of the coin; then if you have further doubt or queries, you could also ask Don to comment. You will surely also get responses from other RC Onliners with their experiences. But beware - if you haven't already tuned in to RC Online - it's addictive.

What with RC Online and SMALLnet, you may find you don't have time to build and fly !

Regards Malcolm Logan - from sunny downtown Bangkok in Thailand.

<  > suggests:

Mike Maupin <  > inquires:

There's been quite a bit of talk about 049 carbs lately. I am fortunate enough to have been presented with a new VA 049 RYOT (Roll Your Own Timing) by a good friend of mine. I don't know what kind of power this motor will put out, but the instructions that came with it (10 pages) say to break it in on a rich 4 cycle at 28,500 with a 5x3 or 6x3 prop -- and that sounds hot to me!

Question is, what kind of carb would fit this engine? I have heard that a G-Mark would fit with some machine work, but does anyone know of anything else that would work -- plus its cost, and where to get it?

This engine is VERY light weight, and if it will turn that kind of rpm, it should make for some great performance on the right plane -- if I can throttle it.

As to Roger Dorn's question about the Super Tigre .11, I obtained a new one of those from an old out-of-business hobby shop. I just picked up a glow plug out of my flight box and screwed it in. I don't even know what it is, but the little ST does well on it. Only thing that I checked the plug for was to make sure it didn't hit the piston.

Mike Maupin, Johnson City, East Tennessee.

Ron Vallejo <  > contributed:

Am surprised to hear about Mr. Bill Wells' Yard Bee being unable to maintain level flight and gain altitude.

I have a YB with the same power package EXCEPT for the Electronic Speed Control (I'm using a 14 Amp Viper ESC, not the 5 Amp controller that comes with the Clancy combination). I didn't break in the motor either. My Yard Bee weighs 12.7 ounces.

It ROGs from a rough pavement at a little over 1/2 throttle. It flies and gains altitude easily on hand-launch on the same setting. Full throttle is unnecessary for take-off and level flight. The only problem I'm having now is at full throttle, the plane goes up nose high, almost close to stalling -- and when I throttle down, the nose drops. This I attribute to inadequate downthrust.

Could Bill's YB be noseheavy?

Ron Vallejo

Colonel Tom Wenzel <  > asserts:

I have tried APC props on my Mouse. That model performs just as well with the new 10x7 APC electric version as it did with the Braun carbon fibre prop. The cost of the APC was under $4, compared to the Braun at $32.

Col. Tom Wenzel