Anyone remember the Jumbo?

I just came across the April 1956 issue of Model Airplane News, which had a plan for a large flapped stunter called Jumbo, by Carl Risteen. Has anyone seen one built or flown? The article says is was for .49 to .60s, and has very large flaps that had less travel than the elevators. It has 1024 square inches of wing area and a 64 inch wingspan. The flaps have a root chord of 5 1/2"! The fuselage is carved out of two blocks and hollowed.

I've always had a thing for digging up obscure designs and building them just to see them fly. But this would be a bit bigger project than I'm typically doing, so I thought I would check the group to see if anyone remember it. I don't expect anything more than vintage performance, but if it is really a dog I'll pass it by.

It probably could use a modern engine. If the moments look at all reasonable you can make it fly OK. 5.5 in wide flaps may make the controls feel pretty heavy.

I have a beautiful Series 20 McCoy 49 earmarked for one of these. .......One day......Sigh.

Ian, are you familiar with the Jumbo, or are you looking in general for something to put your .49 on?

I saw many old article for really pretty airplanes from designers that criticized designs that had "Barndoor wings" I guess this type of design is what they were referring to. Does anybody have any experience with these types of designs? I'm referring to anything that had more than 700 or so squares and little fuselages, whether flapped or not.

Thanks,

I posted the same question a long time ago...and also pretty much just heard the cricket's chiping...if you get my drift. Looks like the only way we will find out is to build one. Tell ya what, you go first! Heh...
Eric V.

Hey, glad you brought up the "Jumbo". I am in the process now of building one. Spent most of the day making the spars and leading edge. Have the main portion of the wing framed up. The big obstacle is the fuselage. Getting blocks that size without spending a fortune. If I can figure out how to do it will post pictures. -DOC Holliday

Doc, you might give Lone Star Balsa a call. They advertise special shapes and sizes. You might also consider glueing two or three planks together for the proper size.

> Doc, you might give Lone Star Balsa a call. They
>advertise special shapes and sizes. You might also consider
>glueing two or three planks together for the proper size.
>
> Bigiron

Hey Bigiron you ole fart, I just put in an order today for the two blocks and some other wood I was getting low on. Getting a Falcon 35 framed up at the same time I am erecting the Jumbo. Showed John Bender the wing and stab today before flying and first words were what 90 are you going to put in it. I think the big Fox 50 aught to work okay. Besides will not be flying 100 foot lines like designer said he used. Later, -DOC

Yes, I mean particularly the Jumbo for the McCoy. I have got copy of the article from Pampa Supplies some time ago, and Andy Housden over here was able to blow up the plan from the Anthology for me. Hence the plan lines are a bit thick, but no problem. I have another question for a 49 stunt ship, but will start another thread rather than hijack this one.

OHH, yess. I have two sets of plans. One set from the day I got the magazine and a later set my daughter found. I look at them all the time, swearing to build one, one of these days. Trouble is all that balsa and the fuse blocks. It is too sexy not to build and like they said before, modern engines will make it fly nice.

I don't know if Bud Nosen (SP?) sells to the public, but I got a top block in an Avanti kit from Tom Dixon that beats ANY AND ALL balsa blocks for sheer size that I have ever seen!!!

It has Bud's red stamp on it. I mean, my goodness, you could almost turn a light baseball bat out of this thing, it's HUGE!

I'm gonna have fun shaping and hollowing this sucker...

Back to the Jumbo - I've always wondered about that beast. I tried figuring the squares on it doing my crude scale up's from that little magazine picture. I kept getting outrageous number and figured I had to be wrong.

Anyone know what the "Stunt Stat's" really are? Square inches, nose moment, tail moment, and tail volume? How thick is the wing at the high point?

Looking at pictures is deceptive, since Carl used those huge fairings into the stab, it appears short coupled. But if you ignore that, the scale looks more stunt like.

Eric V.

Eric. Do you have a set of full size plans? If not , I'll gladly send you a copy of mine. Ty

Thanks everyone for your input. This is a great forum for someone who has been flying alone, and so sporadically, for so long. Its great to see control line comeback.

My figures on wing size came from using the scale on my rough photocopy of the scaled plans in the magazine. My crude measurements show the nose to be 8 3/4" long to the wing LE. The wing chord (less flaps) is about 11 1/2". Flap hinge to elevator hinge is 14 3/4". (The wing is rectangular.) The tail span is about 32"!!

Ty, if you're willing to share the plans, I'd really appreciate it.

Doc, the spans call for two 3" by 1 1/2" by 35" blocks. I bought a three foot long block 3" square of Sig wood at my local hobby shop for $16.61. Lone Star probably would have been better quality and price, but the grain pattern was just right to get two vintage rubber props out of it. An impulse buy... I think the props will have to wait, as a Jumbo fuselage would do it more justice.

Hi John. Send me your snail mail address via the secret communications on this forum. I'll get a set off to you Monday or Tuesday.

>Thanks everyone for your input. This is a great forum for
>someone who has been flying alone, and so sporadically, for
>so long. Its great to see control line comeback.
>
>My figures on wing size came from using the scale on my
>rough photocopy of the scaled plans in the magazine. My
>crude measurements show the nose to be 8 3/4" long to the
>wing LE. The wing chord (less flaps) is about 11 1/2". Flap
>hinge to elevator hinge is 14 3/4". (The wing is
>rectangular.) The tail span is about 32"!!
>
>Ty, if you're willing to share the plans, I'd really
>appreciate it.
>
>Doc, the spans call for two 3" by 1 1/2" by 35" blocks. I
>bought a three foot long block 3" square of Sig wood at my
>local hobby shop for $16.61. Lone Star probably would have
>been better quality and price, but the grain pattern was
>just right to get two vintage rubber props out of it. An
>impulse buy... I think the props will have to wait, as a
>Jumbo fuselage would do it more justice.
>
>John

Just measured the basic wing while putting the rest of the spars in it. Chord= 11.5 inches Span(minuus tips)=60 inches Big wing.DOC

Hi Eric. I guess I'll give you the "stats" on this beast. Based on an original set of MAN plans: WS=64"; root chord=11" not counting flaps; flaps=root=5" X 3 5/8" at tip; nose ring to LE=8 5/8"; TE to TE=14 5/8"; fuselage=35" not counting elevator; horizontal stab/elevator=31 1/4" x 9 1/2" rootx 6 1/4" tip; elevator is 5 1/4" at its center; I came up with 960 square inches of wing area, but it is actually more. I didn't round off the tip area, so it may well be closer to 980 sq. Big by any standard. I love the engine shown, a McCoy rear intake .60, which was used in speed more than anything else. Forgot the vertical stab which is 6 1/2 X 6 1/2". This thing will eat up a lot of balsa. I forgot the rib thickness= 1 5/8".

I really liked the Little (or is it Lil?) Moe or Mo that Rusty Brown? used to fly - who designed that and when and what was the span/area/engine size?

Saw it on one of Windy's Brodak videos.

I have been flying a Taurus which is a non flapped 68" wing with 850 sq. inches. Mine fly's pretty good with a Fox 59 or Anderson Spitfire on spark ign. If it is gusty it does bounce around in the wind. I use 67' lines, and you need cleats on your shoes when it is windy. I think it weighs around 67 oz. with the Anderson. Very fun machine.

Here is a picture of Rusty's Little Moe right before it met it's demise.
Ther eis another Little Moe, by Roy Tranthom, in Florida. I'll get the details from him.

The model in the background is/looks like an Icarus, which is a streamline version of the Taurus previously mentioned. Icarus came in two sizes, 60 and 29. The one in the pic. looks like the smaller one, at least, I hope it is. If not, the Moe is about 10ft. span.

>Here is a picture of Rusty's Little Moe right before it met
>it's demise.
>Ther eis another Little Moe, by Roy Tranthom, in Florida.
>I'll get the details from him.

Hey Robert, both of the planes belong to Rusty and if I remember right were pretty close to the same size. Camera angle probably make the one in back look smaller. Rusty knows how to build and finish the old timers. Later, -DOC

What size is it - who designed it?

A couple months ago inquired about microlite covering from a Carl Risteen. I asked if he was the one that made the Jumbo and he said that indeed it was he. He said it flew well but with the considerable power of the Mac 60 the flaps were prone to fluttering but would pjrobably be OK with less power. Maybe stiffening with carbon veil would be wise. He said later versions had narrower flaps. You might want to contact him for further details. You can contact him at the following E-mail adress.
[email protected]