scottrc

With all the talk about blimps, especially about a design to hold up to the wind and carry payloads, is anybody possibly working the idea of a ridged framed airship? Using composite materials for the frame?

It's got me thinking

Scott

MajorTomski

Scott given that even up to the 50 foot long inflatables are over inflated and fairly rigid, there's no need to waste weight on unnecessary structure found in a dirigible.

Although it would be nice to show up at a scale meet with one. Several months back a gentleman in one of the English RC mags flew a scale model of the R-100, I think it was on the order of 20 feet long.

heli001

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You guys talking about something like this.....?

Ptarmigan

Sounds cool to me. [8D]

CafeenMan

I did the math on this years ago. I figured a scale hindenburg model that was 6' long would not be able to lift even one pound. I couldn't see building it, installing engines and a radio and coming out that light so I scrapped the idea. These things were huge for a reason.

heli001

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Paul,

If I remember correctly (been a few years ago), the ship pictured above was 13.5 feet long, and had a volumn of about 80 cubic feet. The frame work and mylar weighed in at 2 pounds and that left 36 oz for motors and batteries. It was powered by 4 - 280 motors and 3 bladed geared props , and only flew indoors, way too fragile to even think about outside. Was VERY sluggish in control......I have since moved on to polyurathane bags in the 17 to 20 foot range.....much more lift, and with LiPo's weight is no problem.

CafeenMan

Well, my plan at the time was to fly it tethered outdoors. At least that's initially what I wanted to do. I planned to use dual Cox .020 engines and exhaust throttles. This was way back when I knew a heck of a lot less than I do now. But I was never even sure I did the math right. I just looked at the chart of elements and compared hydrogen and helium to oxygen. Hydrogen had an edge in lift, but I'm a smoker.

heli001

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Paul,

The one thing I miss about the rigids is building the frame....it was one of the most complex balsa projects that I have ever attempted, and I have built a few over the years....I found a set of plans, and completely re-designed the framework to add strength and save weight. With the clear mylar skin shrinked, it was pretty impressive.....[X(]

CafeenMan

I still want to build my Hindenburg. In fact, I have some very detailed drawings of it - inside and out. But it won't fly. I don't really have that much interest in airships, but I'd like to build a nice one for display. Flying it would have been nice, but it's optional. I'm more about making it scale than just having one to fly.

I can see how it will be complicated. I plan to jig mine on a piece of conduit when I get to actually building it.

heli001

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Paul,

I used a piece of black steel pipe to support the formers at the keel position (the airship basically hung upside down during the former stringer stage) spaced the formers and added the stringers...kept everything perfectlly aligned.........the internal suspension threads is what really made it strong and "rigid"

I have a set of plans around here somewhere.........

Umi_Ryuzuki

There was a gentleman in England that has built and flown scale models of
the R-100, and R-101. Big, outdoors, and I think he was doing it for a study
of the old airframes, and and aerodynamics.

Someone posted a link a couple months back on another BBS, but I didn't save
the links. I have not been able to find the site since then.
It had images of both the dirigibles he built in a hangar.
It would be worth the time to find out what he has been building.
If you guys should find it post a link, I have had no luck so far.

Ptarmigan

Bump. I thought of something. When I see an inflated RC blimp, it leaves creasing. Maybe if I do it correctly, I can make it look like a dirigible. From there I can make a RC dirigible, that is 5 to 7 feet in length.

50+AirYears

Sometime in the 1980s, someone was flying about a 12 foot long model of the Akron at a Mall show in the Cleveland area. Radio controled, electric power, slow, stately. Also I think the Late Bill Winter publishe a couple plans in American Modeler magazine for both a control line and a radio control blimp. The CL blimp used a couple Cox 020, and the RC blimp controled altitude by rotating the arm the motors were attached too. They both used panels cut from dry cleaning garment bags. Weight was a major concern, as was the fact that helium will slowly difuse through most materials.

Ptarmigan

A control line blimp? Sounds rather odd. Never seen one or heard of it. I know mylar is used for RC blimps. I think mylar is most likely to retain helium the most. I rarely see RC dirigibles. It would sound fun to make one, something less then 12 feet though .

Deltageek2

One pound of lift is a lot to work with. I fly micro R/C and my Skeeter weighs 1 ounce total. The built-in ESC handles 2 amps on the tiny 3 channel proportional RFFS-100 receiver. The magnetic actuators are tiny, a gram or so each but have 100 times less power than the smallest motorized gear servo. Such a tiny system would work in much smaller blimps also considering the weight savings of micro r/c gear.

My RC shop buddy asked me to launch the 19 foot RC blimp for him at the half time show at the hockey game. WOW! On went the cars, the cheerleaders, the T-shirt bazooka brigade then the blimp. It was a lot of fun and got me thinking of tieing blimp video into the house video system with those big monitors all over the place.

For outside work NASA was using a nonrigid blimp with the pointy end facing forward. At the tail was a helicopter rotor-like pusher propeller for propulsion. I believe it was solar powered to some degree and electric.


I am impressed with the semi rigid hotairships with the ultralight style tube and wire frames.

Picture is MicroBlimp from NYBLIMP.COM

fixinJim

I think that several people I've seen the forums are working on them. This is my version. I'm finishing up the airframe and the rudders and elevons and will begin the skin this weekend. It's 15'8" long, 32 " in diameter and will hold 56 cu ft of helium. With the motors controls etc I should have about 5 cu ft more than I need to successfully float it and maneuver in no wind or very light breezes. It's powered by 2 speed 280 motors and micro radio system and micro servos.

MajorTomski

Jim, how do you intend to control you airship, by the normal flight controls or by something in the propwash?

Ptarmigan

Nice model. What material are you using for your airship? I read the practical minimum size for a rigided RC airship is like 9 feet. You can go smaller, but you will have contend with weight.

fixinJim

Major, I have standard rudder and elevon controls similar to the stern planes and rudder of a submarine. The engines also turn with the rudder. The engines will be mounted along the lower sides ablout 3/4 of the way to the rear of the craft. between the two it should be fairly quick to respond for a light ship it's size. If not, I'll modify the control surfaces and/or engine configuration accordingly. I'll pass along more detailed photos as I get the control surgaces and motors in place. It's a labor of love, and half the fun is figuring this stuff out. Of course, that's just my opinion, I could be wrong Jim

fixinJim

Lagopus, Pure balsa, softer grade where it can be used, but fairly hard where strength is needed. The circular struts are bent into shape around various size circles of foam after soaking in water and let dry over night. It's quite workable wet. The biggest problem is maintaining shape during construction and making sure it dosn't get dinged in between times of working on it. I have pullies and a harness around it and raise it to the garage ceiling when I'm not working on it. My SO's mazda fits under it just fine, and I can walk under most of it without putting my head through it The entire airframe with rudder and elevons is 14 oz. With skin, controls, motors etc, it should weigh in at around 43 oz, and I can lift 54 oz of weight based on the size of the helium chamber( 56+ cu ft). The skin is 1 mil aluminized mylar I obtained in 5ft by 25 ft rolls from a garden supply site online. Jim

Ptarmigan

Are you familiar with ptarmigans by any chance before you saw my avatar and username? Lagopus is the genus for ptarmigan. It means "hare feet" because of the feathered feet it has. I wonder if you can use foam, like Depron or blue foam for the rigided structure of the dirigible? Oh, how are you going to transport your dirigible, since it is 15 feet in length? And can this dirigible fly outdoors?

fixinJim

ptarmigan, I'm not sure foam would be any lighter, and I'm not sure how rigid it would be, but it's probably worth investigating. It will be transported in a rigid box 16 ft long and 33 in square. I'll put it in the back of the truck. I'm no sure how much it will be transported, I'm doing this just to say I did it really. I may just take it apart and build something else Jim

jim.jo

It is great to see that peeps have a keen interest in building rigid airships, as I do myself, but how comes this link ended nearly five years ago ?

Has anyone succeeded in completing and flying a rigid airship rc model ?

The guy who build the R100 is called Nigel Wells and he built his with the help of the Airship Association (www.airship-association.org) who can give you more details and links to pics of it.

I have been working on my project for a rigid airship for a couple of years now and have completed all the mathematics and trial models to test the various stages necessary for a practical rc model.

Now unlike other designs I am working on the design concept for a perfect sphere, I have found that the "Zeppelin" design is flawed for small scale in terms of structure and surface area to volume ratios, and that even composite materials have too much flexibility when used in such long lengths needed to make a Zeppelin framework.

I still have more work to do on the next model which will have a diameter of 3.1 metres and a calculated lift capacity of 10 kilogrammes. put here are a few pics that will give an idea of where I am going with this project, these are of tests for the rigid framework.

General Lee Stupid

fixinjim, any update? Id love to see that bad boy completed! What happened to her??