By jakob - 7/12/2013 11:15:31 AM
Hi,
I planning to build an airship that will have a "skeleton structure" made up by carbon fiber that is very similar to this: Link to picture
(structure is made up of a couple of round circles with girders/beams on the side crossing the circles.
diameter of circles is estimated to aprox 500mm and totalt length is about 2500mm.
I'm thinking of aprox 3 circles and 8 beams for the construction.
Maximum load on the structure (from motors or cargo) should not exceed 1kg.
I was planning to use the carbon fiber strip for both circles and beams. Can someone please give some advice to questions below:
1. Any general thought about this? This will be my first carbon fiber project.
2. I would like to keep weight to an absolute minumum, can you please advice on what size of carbon fiber strip you recomend?
3. Can you please confirm that the strips are flexibel enought to make circles from?
4. What would the best way we to bond circles (and beams to circles)? Glue? Could small holes be drilled and bonding be made via some kind av small fastner (blind?). The later would be nice if the construction needs to be changed or disassembled during construction.
Thanks in advance.
BR
Jakob
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By Airship-Jim - 7/30/2013 5:30:33 PM
Hi Jakob.
The material you are using sounds like the same stuff used with inflatables, the normal way to join this type of material is using a type of hot glue and applying this to a fold over join in the material. If you know how to mark out and pre-cut the material to create a cover for the final finish then it should be a pretty straight forward job but will require at least two people to complete.
The issue here is that this would create a bag that can hold the helium but would still require something like a mylar sheet to give a good finish for the outside covering. However you could use this material to create the outside cover to go over the whole framework that is cut to size to fit to the longitudinal strips you plan to use and the joins covered with a separate strip to run along the length.This can be used to contain the helium gas at the same time but you will need to find out more about the effects of hot glue on carbon fibre/epoxy as I have yet to run this test myself.
But again the secondary issue here is the need to build an internal envelope that can be pre-filled with air and allowed to be deflated when the helium is pumped in before being removed via a quick release section in the hull. This is more difficult to achieve but will reduce the final all up weight of your airship and allow you to produce a smaller craft.
Jim
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