Different design - hot air dirigible

Here is a approximate 6 foot diameter dirigible with six sided and 4 sided elements. It weighs 12 pounds.If you want to see it, you will have to send email to solarthermoking@gmail.com. I cannot upload image.

I'm airborne! For $12. 

It's the cheapest price for lifting a pound into the sky. If this can be accomplished, it is easy to expand the size and make the dirigible skin encompass the hot air, and still  stay aloft. it's just a matter of geometry. There is no need of exotic materials or waiting for technology to advance. I have the design already for next  advance, a hot air dirigible that will carry camera.

Cute video, Michael. It reminds me of my only flight, a hydrogen filled garbage bag. I made the hydrogen using old battery acid in a plastic fuel tank that I dropped in some boat zincs, The zincs are used to control corrosion on boats. When the boat is hauled, the old zincs are replaced.
The bag made it over the mountain, last seen headed for Puerto Rico...

I made hot airship to show that hot air can be made useful. There is a structure to the hot air ship, a bamboo ring at the base of the blimp.  It really just a matter of sizing up the concept, so that the structure encloses the hot air mass and its envelop. As soon as that occurs, then the airship moves from a blimp to a dirigible. The next iteration is an airship that can lift its own weight with the hot air contained inside the frame. I have my model made and have constructed my first full size element.. It works. 

Nav could use the technology I developed to construct his vehicle - forget the spars. I already tried that 2 years ago.

I will post pictures when the dirigible is aloft.

<<<I made hot airship to show that hot air can be made useful.>>>

   Maybe, maybe not so sure.  At half the buoyancy of H2, hot air requires twice the volume which means that even an ultralight hotairship would need to be at least 80 feet long.  Heating air is a lot easier than making H2 so it might be worth looking into.
   As far as bamboo framework, could we see some specs on weight vs length and diameter?  To me it seems thick-walled and heavy and overly flexible in the 2" diameters that id want to use.

      I know the Chinese use it for scaffolding 20-story bldgs so its possible.......

Hot air  is a well known  mode  of man lifting  flight  . It is also  very  fuel  hungry  and  even more so in  warm  areas.  The colder  the  area  the better the  lift but it also cools off quicker so the fuel burn   still isnt  good . .    . In hot  humid  areas   It  may not  have the volume to  gain  flight just  because of the surounding air temps  being  high .
  Also  There is a limit of hot air temps in the envelop  to never exceed . That is  220 degrees  F in modern  hot air  balloons  .  Plastics  would be  much less hi   temp survivable   than the nylons used . So   the envelope  would be  extremely hugely !  large   to not over heat  and melt / distort  the plastic . Then  to over come the largeness of the envelope    for powered  and controllable airship flight,  The  power plant  would be  in  the relm of jet engines  for  weight to thrust  ratio to  effectivly  navigate .  And jets  Are just  as thursty making thrust, as maintaining hot air  lift  is .   It would be a incredibly expensive  undertaking .
  However  As yet  I have seem  no  attempt  at building  a  single person FAR 103  legal Hot Air Airship.
 They  do  make  a Single person  Hot air balloon  called a cloud hopper . Some  have  tried to  power  them  with  PPG  equipment , but the  results  were very  limited  to flying in  light to  zero wind  days  with  limited  time aloft  to  only  an  hour or  2   at best. Even  the  4 person  hot Air Airships  are very  limited  in  weather   days  they  can safely  fly  with a limited  time aloft of up to 3 hours  .  
 Its  the size of the envelope to the prevailing  weather  , and the lack of inturnal pressure  of the envelope  to  maintain  a  rigid  form against the  on coming  air   that severly restricts Hot Air Airships use and function.
 But  this is   also  why  Hot air balloons do so well with  many in the sport and loving it.  They  float  with the winds  and have  very little air resistance on the envelope because of this.  So  the envelope  maintains  its  full volume and lift . However should you  try to  go  against  the  wind , the air pressure  from  oncoming  air  would  buckel  the envelope  and push  the hot air out  the bottom , you  would loose  your lift  and maybe  crash .       

My reply on other computer is frozen, so if you want me to reply, email me at solarthermoking@gmail.com

Hi 

Short messages seem to get through. I am going to use mylar, which has a melting point around 455 F. I may go over to aluminum foil, if the weight issue can be managed. I may also go to aluminum tubing, Nav, rather than bamboo. 6 6 foot lengths of bamboo from home depot weigh 1/2 pound, including packaging.18 foot diameter duodecahedron sphere (?) will have probably weigh 36 pounds excluding mylar. maybe 10 pounds for mylar. Should take off with 100 degree differential. Can boost temp if I have to. Not concerned with actual flying model yet. I just want it to lift off, so I can demonstrate the feasibility of the design.

In any case Nav, it will be far easier to purchase more propane, and for a lot less. You lose 5% per day of helium. If you only fly on weekend, you will have to replace 30% or more of the helium. There are other issues. Goodyear blimp has an operating budget of more than $100,000 per month. Hot air machines have much lower operating budget. In my design, there is no need for assembly. Rather than driving to launch airship, I just take off. Air resistance is very low until you go over 45 mph. Stay under that speed, and airship will do very well with small engine.

<<< Hot air machines have much lower operating budget. In my design, there is no need for assembly. Rather than driving to launch airship, I just take off.>>>

   Yep, no doubt about it, there are some cheep! and EZ features about hot air dirigibles.  We are delighted ur working on them and cant wait for some test flights to appear here.!!!  Lets see a breakthrough, Michael!

  Dan Nachbar's "Sky Yacht" is a good fore runner for the hot air approach to "directable" buoyant flight. Its a big 2-person hot-air dirigible and retails for a hundred grand. My goofy calculations say that, Roughly, if i cut the size in half ill have something approaching an ultralight and itd retail for fifty grand meaning itd cost me 25 grand to build, i spose.
   Granted my calcs are goofy but they do seem to say that this approach aint in my target price ballpark which is under $5,000! I'm talkin DIRT cheap here, hehehe.  Working slob price is what the flight world needs now.

   And I'd be ecstatic if there were a way to do it with plain old hot air. Like Inventing said, it takes a lotta propane to stay up and that means heavy pressure tank weight. So my natural first approach would be to work on insulating the hot air to retain its temperature much MUCH longer. That is quite challenging but doable, im sure.

Keep looking UP!

Hi Nav

Before I forget, here is the video showing how to make your spars. the foam spar in the back weighs less than the pvc pipe in the foreground. Same 9 lb brick is the weight in all cases Do the same brick in a bucket with the downspout. Downspout will do ok in comparison, until you have the joint under weight. Foam spar will be completely uniform, with no seam.

As I told you, I figured this out 2 years ago. The analysis that flows from this information shows that your design is too fragile against the leverage that can be applied. Airship will probably be ok in the air. Problems will come upon landing, if any part of the frame touches the ground and there is a wind shift, which happens frequently.One time will be too many.

As I replied to inventing man, the larger you make the volume, and you minimize the expansion of the surface area, physics will work for you. I am thinking of designs that will have a 20 degree temperature differential. They will be huge when compared to a helium lift airship. They may actually take more propane to heat up than a smaller airship, but they will stay aloft for days, rather than hours.Buckminster Fuller figured out that if an aluminum airship 1/2 mile in diameter was heated a 1/2 degree F, it would stay aloft indefinitely, just from the sunlight that heated a black surface inside the 1/2 sphere. Conceivably,  you could have floating cities in the air. Star Wars comes to mind.

The whole issue of having a structure survive different stresses has been on my mind lately, as I had to reinforce my dirigible against the wind, again. It may be too heavy to lift off, If I complete the whole sphere. i am going to just use a 1/2 sphere and have the top 1/2  a plastic balloon. 

I am still shooting for liftoff Saturday. i will load the video up whether the flight is successful or not.

That's a really strong spar. Please list the weight comparisons of each test spar. I presume your geodesic sphere would be made of straight spars forming each panel, with a flat cover over each panel. That would eliminate any curved surfaces, right? Curved surfaces can be a real hassle.
  Let us know how you will attach each panel to the others. I'm looking for light connectors for my plastic panels, something like plastic rivets.

To answer your question about the spar, I did not record the weight for posterity, as I figured there would be ample opportunity to make more. The reason the spar was so much stronger than other configuration is that the spar is 98% foam. The strength comes from the metal mesh embedded in the  foam.

Yes what ever is attached to structure will be on straight lines. The points of attachment have to have something embedded in the foam.

Here is one way to attach spars together