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hoverman
12-01-2010, 09:47 AM
Hello Airshipbuilders,

I thought it was time to make my first post in this forum! I have posted my idea on RCgroups.com before, but I hoped I could reach more airship enthousiasts through this forum.

As a short introduction, my name is Marijn van de Ruit, I live in the Netherlands, and I just finished my Commercial Pilot License. I have been building RC models for more than 8 years now, starting with RC Hovercrafts. Further I have built..airplanes, helicopters up to 1.5m, VTOL's, Hydrofoils, Large Submarines, autogyro's, etc etc, but I could say that my speciality lies with Wing in Ground effect (Ekranoplans). I have posted several of my models on rcgroups and other forums, and I still keep building these models till this day, I just love them:D

Anyway, one could say that I have a passion for airships, I have visited the Museum in Friedrichshafen, have about 23 books on this subject, and I even specially flew to Friedrichshafen with a Diamond DA-42 last summer, so I could see the Zeppelin NT in action. I even got a 'traffic report' from friedrichshafen Approach at 2000 ft, afterwhich I could wittness the Zeppelin passing by above the Bodensee.

So, there is enough enthousiasm:), but as many modellers I know, my dream of building a large outdoor Zeppelin stopped as soon as I started looking into European Helium prices. Nomatter how hard I looked, I never got around this expensive helium. For a moment I considered Hydrogen, but a more rescent experience with an structurally failing tail rotor on a 1.5m BO-105 Helicopter(with me ending up unconscious with 12 stitches in my forehead), changed my thoughts about risky materials on RC models!

So, first I had thought about building an RC Hot air Airship using a simble camping butane burner, but a few calculations showed that such a model had to be extremely large in order to provide enough usefull lift. Not that that is a problem..but it requires professional butane burners, and this is just..well the same story of the helicopter again.:rolleyes:

So, my outdoor airship idea stranded here and has been on hold for quite a while. Then some time ago, when I was looking at one of my VTOL's, I had this idea.."nowadays, everything can fly, with modern brushless engines and lipos" So.. an airship can also fly, using shear overpower. Modern airship hulls can produce quite some dynamic lift at various angles of attack, in combination with enough power I could build an airship that flies without any sort of lifting gas.

So..at first I started looking if somebody else has had this idea, and I found The Martian Spaceship, by Roy Clough:

http://i218.photobucket.com/albums/cc320/Helipilot/yokota.jpg
http://i218.photobucket.com/albums/cc320/Helipilot/lg-72116.jpg
http://i218.photobucket.com/albums/cc320/Helipilot/Jh15540.jpg

So, yes, this works! But, I have to admit that this model above isn't quite what I had in mind. I am looking for an airship, not a spaceship. On the other side, the power to weight ratio of brushless/lipo propulsion is far superiour of what this old design is using.

hoverman
12-01-2010, 09:49 AM
So, I made some drawings, soem of them are quite old and full of errors, but they might be interesting anyway!
Image (http://i218.photobucket.com/albums/cc320/Helipilot/img174.jpg)
Image (http://i218.photobucket.com/albums/cc320/Helipilot/img175.jpg)
Image (http://i218.photobucket.com/albums/cc320/Helipilot/img176.jpg)
Image (http://i218.photobucket.com/albums/cc320/Helipilot/img210.jpg)
Image (http://i218.photobucket.com/albums/cc320/Helipilot/img212.jpg)
Image (http://i218.photobucket.com/albums/cc320/Helipilot/img213.jpg)
Image (http://i218.photobucket.com/albums/cc320/Helipilot/img214.jpg)

Hope to hear your thoughts and ideas, anything is welcome!

Marijn van de Ruit

The Netherlands

joec
12-01-2010, 07:07 PM
Marijn, Welcome! Those are fantastic drawings. The whole thing seems workable to me, you certainly seem to have what you need to do it. The idea of overpower is well taken. I recall long ago asking my dad why I can't put an electric motor and battery in a model plane and fly it; "too heavy, it would never work". Good example of why you should never say never.

Coupling the power aspect with micro electronics and you could make just about anything fly. Looking forward to seeing it go together. JoeC

hoverman
12-05-2010, 07:09 AM
Well, than I am really starting to look forward to some results:)

I also made some progress, I bought a small Iron, with a teflon coating, and made some small envelopes using either polyethelene, pvc or polypropylene.

Today I made this larger envelope:
http://i218.photobucket.com/albums/cc320/Helipilot/DSCN4762.jpg
http://i218.photobucket.com/albums/cc320/Helipilot/DSCN4763.jpg
http://i218.photobucket.com/albums/cc320/Helipilot/DSCN4780.jpg
http://i218.photobucket.com/albums/cc320/Helipilot/DSCN4781.jpg
It's not very good, it's shape isn't either, but ahwell, I learned a lot, and I'm quite happy about it for a first try:)

Still, I think making a ripstop nylon envelope for the RC model is a good idea, this material is nice for Lighter than air flight, but for bush flying it won't last a week..

Marijn

GraemeEllis
01-15-2011, 07:58 PM
There is some rational behind your idea - airships were commonly trimmed be heavier than air while flying, the dynamic lift of the envelope would keep it up at speed.

I'm interested in seeing more of your development - I would like to built a large (2 meter) Schutte-Lanz bomber type airship but don't want to have to invest in helium or religious weight restrictions.

Good luck!

hoverman
01-16-2011, 11:02 AM
I haven't really been able to work on it, and I have to admit that I have been working more on some other projects lately:o

It's funny that you mentioned you would like to build a Schutt-Lanz bomber, I have allways wanted to build something like the L48 or L70, using this method, which is also how I came to this idea ;)

Marijn

GraemeEllis
01-20-2011, 08:49 AM
I am thinking of doing a largeish model, with a super light balsa and foam structure, and tissue or mylar covering.
This would not nessesarily be a heavier than air model, but built as lightly as possible for 3 channel control. Boyancy will be achieved with several helium filled balloons within the structure, ala the full scale method.
The nose will be removable so it is easy to replace these balloons. Lift will not be as efficiant as a non rigid or single cell envelope, but it will be easier to repair and cover, as the envelope does not have to remain airtight.

It will be trimmed slightly heavy, and rely on dynamic lift to stay in the air.

I am building the earlier Shutte Lanz type airship as the shape appears to provide the most lift at any airspeed.

Good luck with your build!

hoverman
05-08-2011, 07:12 AM
Well, it has been a real while, but I came back to the concept of the heavier than air Zep.

But..with quite some revisions! This time I went for the thrust vectoring idea, and I was going to use large balloons as envelopes. I can buy 2,5m 'zeppelin' balloons, for 4 euro's a piece. They are quite durable, as long as you don't crash them into bushes or other sharp things.

www.bubblexl.nl

Anyway, thrust vectoring, balloons, time for a sketch!
http://i218.photobucket.com/albums/cc320/Helipilot/img347.jpg

And time for a prototype. I spent the whole day doing rapid prototyping, and this is what came out:

http://i218.photobucket.com/albums/cc320/Helipilot/DSCN5110.jpg
http://i218.photobucket.com/albums/cc320/Helipilot/DSCN5113.jpg
http://i218.photobucket.com/albums/cc320/Helipilot/DSCN5124.jpg
http://i218.photobucket.com/albums/cc320/Helipilot/DSCN5126.jpg

And I tested it, the first test was quite dissapointing, as I damaged the balloon before I managed to get it up int the air. The next test(new balloon) was a lot more succesfull. Turns out, it flies, it has enough power to nearly go vertical.

The thrust vectoring works OK, however the current Thrust line/CG position is not correct, and I wasn't able to make a pitch down controll yet. I crashed it after anbout 40 seconds after a looping, time to order some new balloons!

Marijn