weight limit for 1/2A
 

What's a good weight for a 1/2A, powered by a cox golden bee?Built up wing. 5.5 oz ok?

That should be OK.

Thanks for the comment jim

Hi Jay, besides total weight, please consider wing loading as a very important factor

concerning flight performance. The lighter the wing loading; the better will be the

performance. Taking 5.5ozs as a base weight, 5.5 ozs in a 100sq" wing will not fly as

well as 5.5ozs for a 200 sq" wing.

Tony

When I was a kid I built a lot of Sientific kits. The solid balsa airplanes all had 18" wing span and the built up wing airplanes were 22" span. They were reasonably fast and could tolerate resonable wind up to about 10 mph. I got for my 12th birthday a Berkley Aeronca C3 kit with 36" span. It flew good but it was slow and could not tolerate more than 3 MPH wind.

There were some half-A built up wing Scientifics with 22 inch span, but others were 18 inch. I built the Sizzlin' Liz P-51 and Grumman Hellcat, both with built up wings and built up fuselage with plastic turtle deck, both were 18 inch spans. The Hellcat kit was my 11th birthday present. The solid balsa wing half-A's were very durable compared with the plastic ready to fly's, which tended to shatter (or should I say implode) into a shower of particles upon hard impact with the earth.

The 5.5 oz is including the engine.

Are you saying the more wing area is better?

This is a scratch built, it is 13" long from the prop to the t/e of the elavator, and the wing is 23" L and is 5 1/2" wide down to 4 1/2" at the wing tip.

That seems reasonable to me.

That's what I'm saying. Lets be reasonable of course, you can exceed practicality

with too much area for the engine power. Look at the TD .049 generation of 1/2A

combat designs. a practical wing area for the TD was 190-220 sq"s, usually built

to 5.5-6 ozs ready to fly weight. They flew fast enough to approach the limits of

my ability to fly them. I flew 190 and 200 sq" designs that I propped for 72-73 mph

sans streamer; I propped my sons' combat models to fly 74-75mph( I couldn't control

them at that speed). Our 1/2A models weighed 4.9-5.5ozs, They had composite wings,

built up wood superstructure with foam LEs. I even designed and built what was know as a "Floater"

It flew spectacularly, it looked sorta like a "Sickle" design and had 270sq"s area and weighed

5.4 ozs ready to fly. It gave away about 6mph to the normal 72 mph models but out turned any

1/2A I've ever seen. It flew 6' diameter loops(measured by me and others) at 65-66mph.

That is what low wing loading will buy for you. It also paid the price all "Floaters" pay; It

died a glorious death when "bellcranked" by an opponent that hadn't realized his streamer

was taken so quickly. :D

Tony

Tony

Interesting info, Tony, great stuff. My Ringmaster Jr. with OS .15FP-S is 200 sq. in. of area. What you just told me is that if the Ring Jr. was built light enough, a Tee Dee or Norvel could haul it no sweat.

The OS engine is too heavy for it, have added ballast to the tail so CG falls were it should. It is a pig of plane because it is built from Sterling kit wood, which was heavy to begin with. The OS is a bit overpowering for it. I do 4 second laps on 58 feet lines. It doesn't stunt well at all due to weight.

http://www.rcuniverse.com/forum/atta...mentid=1945661Hi George, I built a succession of Ring Jrs, I built a Ring Jr back in 1954(1955?) and powered it with a Cub .099. It flew

very well back then, preforming horizontal, vertical and overhead eights. I did some maneuvers that were supposed to be

square loops but really weren't. The Cub .099 had about the same power as a strong Cox reed valve .049.


So I started a new series of Ring Jrs about 15 years ago building a Jr from a kit and powering it with an AM 1.0 cc

diesel engine. that model did every maneuver in the pattern. I built a few longer span larger area Jrs, powered

with PAW and Taifun .09 diesels. They flew just like the AM 1.0cc version. Then I optimized the Jr design for

the PAW 080cc(.049cu") series. using a much shorter nose moment, same tail moment with reduced area fin

and stab/elevator. These models weighed 6.8-7.2ozs with prop, ready to fly. This latest version flew the best,

also flew a bit faster, It retained the Jr's 195sq" wing area, I flew the last versions on 44' x .008" stranded lines.

The only modification that I would make to the design would bump the wing area up to 225 or 230 sq"s.

I've got photos of the last Ring Jr; I'll try to attach them. Hmm, this pic post isn't exactly what I intended.

If you wanna see more photos, send me an email.

Oh, George, just checked, and I see that you've already seen photos of my last Ringmaster Jr. I'll see you later...


Tony

Tony, I just weighed my Ringmaster Jr., .15FP w/o muffler is 17.3 ounces, over twice what yours weighs. Yes, you have a nice Ring Jr. there.