Goldberg "Sailplane"

[donjiskra]

Jim is doing a beautiful job on his awesome "Sailplane" and is wondering how to install servos and receiver, since the 1940 plans, naturally didn't use R/C gear at that time.
Anyone have suggestions?????
Thanks,
Don

[AEAJR]

First you need to define what moveable surfaces you will have.

That looks like it might be a free flight glider. If so, it probably has plenty of dihedral in the wings, so you could set it up for Rudder/Elevator controls. Very common on sailplanes.

Depending on the balance of the plane, servos could be mounted in the tail or in the nose with control rods going to the back.

Can you post a photo of the fuselage?

Mini or micro servos should be fine.

How do you propose to fly it?

Hand launch?
Hi-start?
Winch?
Slope soaring?

Glad to help if I can.

[Sky Sharkster]

Hi Don, Jim is doing a great job! The Goldberg Sailplane is one of the most beautiful models ever designed. Hope to see some flight shots!
I've converted a few O/Ters to R/C, my suggestion is to use hard balsa strip stock (3/16"-1/4" square) for the pushrods, with a short piece of "L" shaped threaded rod on the tail end, a "Z" bend of regular M.W. on the servo end, attached with thread + glue. This is lightweight, strong in compression/extension and looks "right' among all those sticks.
For the servos and R/X, I use a lightply frame, with 1/8" balsa side rails. It's mostly cut out, made slightly larger than the "hole" size and gets glued to a convenient stringer on each side. It's just behind the C.G., I leave a large open space in front for battery fore-and-aft shift until I get the C.G. right. The RX antenna can run through the fuselage, there's very little metal or F/G to interfere with the signal.
Although the elevator is fairly sensitive on these models, they need a good-sized rudder, like 40% of total vertical area and plenty of throw. I guess the large dihedral angle reduces the rudder effectiveness.
Last suggestion, cover it with "Transparent" covering, it would be a shame to hide all that work!
Good Luck!
Ron

[donjiskra]

Ed & Ron,
Thanks for your comments, they are appreciated.
Jim plans on 3 channels, no ailerons and wants to keep the servos inside.

The Goldberg "Sailplane" is a beautiful elliptical design and was originally designed for an ingition gasoline engine, which would have a short limited engine run to get up to altitude and then perform as a sailplane. I tried to talk him into electric motorization but he's into Giant Scale with glow engines. I sure wish he'd build one for me, as I'm strictly electric.

I'll pass your comments on to him.

Thanks,
Don

[Cecil M Wethy]

When Comet kitted the Goldberg Sailplane, RC models
were being built. Comet kitted a 10 foot Goldberg
Clipper about this time. AMA [Pond] I believe has
the plan. The Goldberg Sailplane would have been
great for RC, but at the time the RC equipment
available was too large to fit in the fuselage. I still
have a Comet Sailplane kit from 1946, which was
priced at $4.95. Cecil

[donjiskra]

Cecil,
That's very informative. Times sure have made many significant changes in our hobby. I'm very excited to see Jim's "Sailplane" inflight.
He's an incredible builder, very meticulous and an excellent pilot.
I'll shoot some videos when it's airborn, later this soring.

BTW, want to sell your kit?

Don

[AEAJR]

Servos of the size of Hitec HS-81s would probably meet your needs.

A micro receiver, such as the Hitec Electron 6 would work.

Hope that helps.

[donjiskra]

Thanks Ed,
Good suggestions.
Don

[Cecil M Wethy]

Don, I am not sure all of it is there. I have been a Goldberg fan since I was a kid. He was way ahead of his time in indoor, free flight and later RC.
I believe the kit would be worth more as a souvinir. I have a copyimg source that is very reasonal and can make you a copy if you want to
build one. I also have a 1/2 size plan [36"]. LMK if either of these insterest
you.
On the Comet 10 foot RC Clipper, Hal DeBolt put a article on it in MAN in
either 1991 or 2 from pictures and info I sent him. I have a copy here somewhere, the article was "Florida Clipper". It was powered with a
Forster "99". Cecil

[donjiskra]

Thanks Cecil,
Appreciate your information and comments.
I no longer have the dexterity for building but thought perhaps a reader to this post might be interested. It sure is a beautiful bird.
Jim has completed the servo installation, after using his years of building and ingenuity. Soon it will be covered but he won't fly it until spring, here in Illinois. I'll take some photos of it when he brings it for "planes for points" at one of our club meetings.
Don

[oian]

Tandy Walker has a very detailed build log for the Comet Sailplane (100 pages and over 200 photos) showing every step in the construction including hatches, radio mounting, engine mounting, control surfaces etc.

[oian]

Forum rules do not allow one to put a link in a post until after your third post, the previous post was my third, so here is in my fourth post and the link. www.sam15/walkersailplaneproj.html (http://www.sam15/walkersailplaneproj.html)

[Sky Sharkster]

Hello Oian.
The link you provided wasn't working. I found the article here;
http://www.sam15.org/walkersailplaneproj.html
And here;
http://www.sam15.org/projectindex.html
For anyone interested in a smaller version of the Sailplane, here's a 36" wingspan kit from Penn Valley;
http://www.pennvalleyhobbycenter.com/rubber/rnkits/109sailplane.htm
And photos of the kit.
Ron

[donjiskra]

Ron and other Sailplane admirers,
Here's a video of Jim's beautiful "Sailplane", enjoy.
http://www.youtube.com/watch?v=h85sjKn9gyQ
What a magnificent flyer she is.
Don

[RogerQ]

Hi to you all: I had a Goldberg Sailplane, one of the most beautiful planes I ever had:
I put an O.S. 26 four stroke on it: wish I could find another kit: I would put electric in it now. I put the servos right at the center of the fuse on the CG. Plenty of room for two HS-81's and then room for a HS 55 for the throttle. It flew wonderfully. Get it up high, cut the throttle and search for thermals. Wow! what a treat. Roger Q

[pval3]

Hey there

beauty of a build and very intricate.

It is so hard for "modern modellers" to understand the beauty of your work as the majority are ARF addicts and have no clue where to even begin with such a project.

How are you planning to power it - or not . . what is the weight. Before you really decide on servos and the like, let us know what weight you are shooting for to ensure the proper load capability. I would hate to see a lighter torque servo stall out on you and loose that plane.

Phil

[mred]

That is one great looking plane. I had a very hard time deciding between that and the Goldberg Valkyrie. I thought about it for about 6 months and the Valkyrie finally won out. I am about ready to start building the Valkyrie and maybe have it ready for the spring season. Yous is beautiful though and you have one great looking and flying plane. I'm going electric on mine, but will be adding rudder and elevator for R/C flying just like yours. Congratulations on a very nice plane.

Ed