Is there no limits to Papercraft?

[mbauer]

Hi Plastic Bonsai,

Is there no limits to Papercraft?
Yes, there is one thing you probably won't hear or see using paper unless it is synthetic (Yupo Synthetic that is).
I doubt anyone is going to release one from a submarine!

Just MHO. Probably wrong though....

Best regards,
Mike Bauer

[bigbenn]

Hi Mike,
There are a lot of r/c aircraft for sale on e.bay which are built of foam and supposed to be relatively strong if you prang them. In the US "Banana Hobby" sell them.
However, they all fly with electric powered jet engines. Perhaps your paper project jet might fly with that sort of power instead of a pulse jet.
I also obtained an e.book recently on how to build a Tesla Turbine, perhaps that might be a power option as well.
I though pulse jets had to get up to a certain speed before they would work, or am I thinking of something else? possibly a ram jet??????
BigBenn

[mbauer]

Hi Bigbenn,

The pulsejet is a personal challenge. I have had some of my models fly on RC electric.

Yes, the ramjet is the one you're thinking of. Not to get to far from this amazing space paper airplane project, you could do a search for Chinese valveless pulsejet, as well as just pulsejet.

There was a guy selling them on ebay a year or two a go, Beck Technologies. I bought one of his smallest to mount in a paper airplane. Still working on the issues, but some day plan to fly it.

Mike Bauer

[bigbenn]

Hi Mike,
I had a quick look on Google and have located the Chinese valveless pulsejet you mentioned having purchased and now I am up to speed.
The r/c electric jets are available now on e.Bay in Australia and I was tempted to have a go for one of them, but decided in the end it was too far off my interests and missed out. Mig - Berkholt? Forward slanting wings, cost of the model around A$640 but on e.Bay auction, I could have got it for around A$300.
In view of what's available now to the average bloke on e.Bay, I think this space paper plane is daft, and building it from drinking straws is even more ridiculous - when so much more of a model could be made in paper/card and fibreglassed to create a surprisingly strong and light re-entry vehicle, so to speak.
BigBenn

[mbauer]

Originally Posted by bigbenn

Hi Mike,
In view of what's available now to the average bloke on e.Bay, I think this space paper plane is daft, and building it from drinking straws is even more ridiculous - when so much more of a model could be made in paper/card and fibreglassed to create a surprisingly strong and light re-entry vehicle, so to speak.
BigBenn

Hi Bigbenn,

The plastic straw one is interesting from the view of what others are trying.

The one getting released from the ISS is truely amazing. $300,000 investment, astronauts and engineers that are looking at it for research of future spacecraft. Single sheet of paper, glass protection, high speed wind tunnel (hypersonic)...

Now that is something to watch in my book. Went so far as to email some questions about it to the University of Tokyo. Doubt that I will receive any replies, but just had to ask if it has been released yet.

True the fiberglass might strengthen it, but it would probably be too heavy and attain much higher re-entry speeds.

The glass that they are using to protect it at the university would be interesting to see how/what they are using and applied by.

Mike Bauer

[bigbenn]

Hi Mike,
I had a look at the pulsejet engine and there seem to be only two problems that I can see, with regards to making a paper plane to be powered by it.
1) When working the engine gets red/yellow hot, which is bloody hot if you will excuse my French.
2) You have to have a paper model big enough to carry a gas bottle which weighs a couple of stone in weight and the area inside the model for it to fit.
Those two questions aside, it should be relatively straight forward!!!
How big were you thinking of anyway?
Richard

[mbauer]

Hi Bigbenn,

Yep, it sure does. Ceramic Paper is lightweight and can handle 2600deg F. Wrapping it inside the nacelle to protect the paper cardstock. Hardest part is using the right sized flat piece of stainless steel to mount the engine to the airplane. Layered cardstock and sandwich of ceramic paper hopefully will work. Pulsejet is 1900 deg F. 2200 deg F exhaust...

Power shot propane bottle is small and lightweight, they are used for the smaller propane powered torches here in the US. Can is less than 8-oz filled. 3/4 size of a can of spray paint!

Aluminum fuel lines until the point where they enter the nacelle and then some stainless steel, which is wrapped around the combustion chamber.

It was hard finding a 1/4 turn fuel valve to use as a throttle, found one on-line for a barbaque, beside the engine this is the heaviest item.

All in all model weighs around 2.5lbs, thrust is 1lb, which doesn't work. Been looking for a smaller lighter model to use (something like the D21 drone). The V1 is a very simple and strong choice, but with everyting sized to fit the pulsejet, it is too big, been thinking about completely getting rid of the paper nacelle with the puslejet in the open on top. This gets rid of a couple of issues.

Oh, and don't forget the Huge servo needed to turn the valve!

Mike Bauer

[bigbenn]

Hi Mike,
I have found, years ago when I first started building card ships for r/c that it is easy to build ships hulls in card and then buy a 2 part mix of fibreglass resin and mix that up and while it is still liquid, brush it over the card hull, inside and out. (Outside of course, the fumes are deadly)
Any fibreglassing manufacturer has the materials to hand. You won't need the fibreglass cloth because the card does the same job.
The resin sinks into the card and the card forms the structure around which the fibreglass dries, so the card is encased by the fibreglass cured resin. You don't have long, only about 5 minutes or so. Once the resin starts to harden, its useless.
Take that one step further. If you built a card model with the appropriate wingspan required for lift and fibreglassed it as a completed unit, it should be strong enough to carry the weight factor and fibreglass is resistant to heat - I think, so with your ceramic cloth included in the construction, you should be OK.
If you build a plane with no dihedral of the wings, I would suggest a high wing aeroplane for added stability, so that the wings are at right angles to the fuselage and balance the airplane by putting a pin in the top side of the fuselage tied to a piece of string, roughly half way down the centre of the front wing and add weight to the nose or tail to get the model to hang horizontally, then you should get it to fly correctly, when you launch it into the wind.
I would be inclined to have the jet running before I launched the plane to remove the need for a servo to turn the fuel on, after all, the gas bottle you describe, won't have a very long running time, I would expect.
If you have a look at the blurb I put up on:- Ojimak paper plane downloads, page 7 & page 8, you might get some ideas on a launch procedure which might work and also some paper airplanes which might be suitable if enlarged, if you went for a scale or semi scale model.
The other thing you must do is to take a movie of the launch and flight of this bird. I would love to see a successfull completion to this, especially if I have had my dubious hand in it!!
LOL
Richard (BigBenn)