Powered Hang Glider for Under 500 Bucks

[Phrak]

I really really, really need one right now---building or flying it, and built from the ground up.

Imagine for a moment that you were foolish enough to consider building one and flying it. And the rules and regulations of the USHGA (that's the US hang gliding association) don't concern you one bit. Screw authority and the horse they rod in on.
Maybe $500 is a little slim. Call it 1000. Parts and Tooling go into cost.

How would you do it once you decided you could?

 

[stevenb]

Step one is to write your suicide letter, to explain why you no longer value your life.

 

[Phrak]

Step one is to write your suicide letter, to explain why you no longer value your life.

Well, thankyouverymuch stevenb. Anything constructive?

Are we that dependent upon manufactured products that no one as a clue how to build your own?
Otto Lilienthal would be rolling in his grave beside himself.

 

[JaredJames]

I've always wanted to build something like this. Would take some real balls to actually test it with a significant height drop though (big cliff where I live).

Well I'd use a pre-built model to gauge wing size and lift capability and copy the wing design from it. This purely to reduce the need for calculations.

Make sure your materials are of similar total weight to the pre-built weight.

If you want to design it yourself, that could add a whole other aspect of difficulty (and risk during testing).

 

[Phrak]

I wouldn't go jumping off of any cliffs before learning on bunny slops, jerednjames.

I've owned and flown a couple kites--I want to fly one I designed and built. Bamboo and polyethylene film construction is very attractive in my minimalist ideals but the weight seems prohibitive.

So I've looked into 6061-T6 aircraft grade, seamless aluminum tubing. It's reasonably priced at 1" diameters (25.4 mm).It appears to go at 10 bucks per 72 inch lengths. I have in mind a biplane canard with wingtip vertical stabilizers.

You're a Brit aren't you? I hope these units and designations aren't too strange.

I detest infernal combustion engines and their noise, and think flying is best done without them. But it may only be needed for take-off and short duration. And also, an electric motor system could come with the same power to weight ratio if it's only good for 5 minutes or so.

 

[JaredJames]

I'm good with the units, sounds like a plan.

That tubing sounds like a fantastic price.

A canard design could be tricky. I always remember my lecturer in aerodynamics explaining that such designs can have stability issues, but we never really went deeper into it so I just quickly skimmed the wiki article and it flagged another issue which may be important to you:

pitch stability flight safety requirements dictate that the canard must stall before the main wing, so the main wing can never reach its maximum lift capability. Hence, the main wing must then be larger than on the conventional configuration, which increases its weight and profile drag.

http://en.wikipedia.org/wiki/Canard_(aeronautics)

So it may cause you to have a higher than necessary size / weight for the main wing.

And then I'm not sure if the biplane idea would be the best. In this particular case, I can't say if you need the extra wing and then if that wings lift would give enough benefit for the extra weight.

Wing tip stabilisers, possibly. I know on large jets they allow you to have a wing ~5% shorter than you would require without them. So they could be a benefit.

 

[AlephZero]

Are we that dependent upon manufactured products that no one as a clue how to build your own?
Otto Lilienthal would be rolling in his grave beside himself.

Part of the problem is that modern "manufactured product" designs are too sophisticated to build safely "by hand". Hacking away at a sheet of ripstop nylon with kitchen scissors isn't accurate enough, and hand sewing woudn't handle the high wing loadings safely.

If you want to build something from scratch, try to find a design from the 1980s or earlier. It won't win any prizes for high performance, but it will fly perfectly well within its limitations.

 

[Phrak]

I'm good with the units, sounds like a plan.

That tubing sounds like a fantastic price.

A canard design could be tricky. I always remember my lecturer in aerodynamics explaining that such designs can have stability issues, but we never really went deeper into it so I just quickly skimmed the wiki article and it flagged another issue which may be important to you:

http://en.wikipedia.org/wiki/Canard_(aeronautics)

So it may cause you to have a higher than necessary size / weight for the main wing.

Thanks for the heads-up. I'll look into it. This explains my uneasiness with canards after examining many in-flight photographs. In enough of them, the angle of attack of the horizontal stabilizer seems to be in or near stall.

And then I'm not sure if the biplane idea would be the best. In this particular case, I can't say if you need the extra wing and then if that wings lift would give enough benefit for the extra weight.

I like the idea of a biplane because it is robust. I don't like it because of all the parasitic drag from struts and guy wires.

Wing tip stabilizers, possibly. I know on large jets they allow you to have a wing ~5% shorter than you would require without them. So they could be a benefit.

I was not thinking in terms of greater L/D, but yaw stability.

 

[Phrak]

If you want to build something from scratch, try to find a design from the 1980s or earlier. It won't win any prizes for high performance, but it will fly perfectly well within its limitations.

Like this?

Just kidding.

 

[stevenb]

Well, thankyouverymuch stevenb. Anything constructive?

Something constructive? Sure, if you consider saving a human life constructive, but not my own words.

" The EAA will tell it to you straight - 'If you want to build something, fine, you can probably do that. If you want to fly something, buy something'. "http://www.hang-gliding.no/article/id/3

Are we that dependent upon manufactured products that no one as a clue how to build your own?
Otto Lilienthal would be rolling in his grave beside himself.

Do you know anything about engineering? The time and cost associated with designing, prototyping and testing designs will far surpass the cost of the purchase of a new design. And, you can not do either with a $1000 budget. Sure, you can slap a $1000 kite together using plans and books from the 1980s, but you will not survive anything beyond a few hops down a gentle hill with that.

The other factor is that you are crazy to not take advantage of training from professionals, and no professional is going to train you on something you slapped together in your garage.

So yes, based on common sense with regards to safety, cost and performance, we are dependent on manufactured products in most cases.

Who cares about Otto? If you don't smarten up, you will be rolling in your own grave soon.

 

[Phrak]

This seems to be the wrong forum for these interests.