DeBolt's Half-A Twin

I've been preparing a bunch of Cox parts for the Bay and realized that I have two pretty good Baby Bee's. Hmmmmmmmmmmm! And I've always had a "thing" for the DeBolt Half-A Twin. If you recall, this was published in Air Trails December 1951. Problem being it was designed around two Atwood Wasp's, presumably much smaller and less powerful than the Cox Bee's. The published plan has a wing span of Approx. 26 inches. I'm going to assume that would be too small for a twin with two Bee's.

Not being much of a 1/2 A maven myself, would anyone out there care to take a whack at what size Hal's twin should be scaled up to for two Baby Bee's? I don't suppose the scaled up version would be OTS legal, but that's not real important anyway...

Crazy Ward-O




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I doubt that a Baby Bee is much, if any, more powerful than a Wasp. 26 in does sound small. 32 in would sound better, I think.

Hello WEVD
I believe you will do fine with the two silver bees with this beautiful plane.
I do have the original full size 1/A TWIN plan Designed by H deBolt. It is a fairly heavy kit. We had two silver bees on it and it flew slightly faster than the Lil Satan with a golden bee on it.
It is pictured with two Wasp .049
Accessories on engine as printed: Torp .049, Cub.049, Mac.049 Cub.039
Plane was design to fly clock wise, easily converted. If you want plan contact me. I could send it JPEG to you.

Hi Ward! This comment will not help you at all, but I too always liked Hal's half-a twin from the '50s, along with many of his other designs. He was of course a hero of mine and I was pleased to meet and work a bit with him on a project years later. Years after that I made two larger versions generally based on the layout and appearance of his model. One had two OS .40s and the other was a twin foamy electric, both RC. And both were fun! They were published and I still have them both and fly them on occasion.

Dick S.


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I'd stay with the 26" span for the Bees. My Wasps are as good or better than the standard Babe Bee. To preserve the CG you may want to shorten the nacelles so that the props on the Bees are at the same location as the tankless Wasps.

The ideas to have it so it doesnt fall out of the sky on one engine.
So other than the position of the firewalls/mounts ,for the correct c.g. , theres only 'sufficent glue' so it doesnt fall apart to worry about .

Seriously , To much power ? thats what will keep the lines tight .

Ward-o:

Check with Jim & Todd Lee. They've built those (stock), and can tell you what they used for power...and the results.

Want their E-addresses? Send me a PM.

mk

>I've been preparing a bunch of Cox parts for the Bay and
>realized that I have two pretty good Baby Bee's. Hmmmmmmmmmmm!
>And I've always had a "thing" for the DeBolt Half-A
>Twin. If you recall, this was published in Air Trails December
>1951. Problem being it was designed around two Atwood Wasp's,
>presumably much smaller and less powerful than the Cox Bee's.
>The published plan has a wing span of Approx. 26 inches. I'm
>going to assume that would be too small for a twin with two
>Bee's.
>
>Not being much of a 1/2 A maven myself, would anyone out there
>care to take a whack at what size Hal's twin should be scaled
>up to for two Baby Bee's? I don't suppose the scaled up
>version would be OTS legal, but that's not real important
>anyway...
>
>Crazy Ward-O

Hi Craze, Please think scaling in terms of wing area...not wingspan.
Two Baby Bees should equal an OK Cub .099 in power, and I flew a Ringmaster Jr
and a Wee Duper Zilch with a Cub .099. They both flew great. So I'll
suggest scaling to 200-240 sq"s. Good luck with your Half-A Twin, I think
its a great idea.
Tony G

Two twin lung Cox reed valve engines, such as the Black Widow, should not overpower a 26" span model. Start out with 3" pitch, maybe a 5.5 or 6" diameter. When the OB engine dies, the single engine should be enough to keep it out on the lines OK.

Currell

Also, consider removing the tanks from the engines, using RTF backplates and external stunt tanks or balloon tanks. That way you can fly inverted.

For best performance, put the cylinder heads toward the center, not up or down. This will reduce stuttering in inside/outside transitions.

I agree with the sizes, but would stay more toward the 240 sq.in range.

Unfortunately, for competition, .012 lines are required since you are over .08 cu.in. You should still be able to fly out at 40' or more, even so.

I had 2 of those as a kid. One was powered by Atwood Wasps and the other OK Cub B's. Both of them didn't set the world on fire but they were sure'neat' out on the lines.
As I remember, Cox 049's didn't fit on the firewalls.
Were I building one today the carved block nacelles would have to go. Have you priced a balsa block recently.
dennis