Project Bush Demon

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Arkan

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Interesting how many of them are gone. Very few alternative engines have proven to be successful.
the question is have they failed due to thier design, or have they failed because sales are limited. Aircraft companies built very few airplanes each year, motor demand is low. You could have the best design, top of the line equipment and materials, and fail to break into the market.

There will always be those who doubt your design, and universal agreement has never happened in the history of the world. Start up cost for engine manufacturer are astronomical, and in aircraft engines, it takes decades to build a customer base. This is why most will start ups will fail, and why advancements are slow to come in aviation engines.

personally I think another reason advancements are slow coming to aviation aircraft engines, a lot of designers and pilots are Leary of new technologies, no one wants an engine failure while in the air. So they are reluctant to try new tech until it is proven.

in Short if an engine company fails, it may not be due to poor design or bad products, it may just be they ran out of money due to the limited market and had to go out of business.
 

Victor Bravo

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I was actually not trying to be confrontational in the very least, my motivation was straight-up curiosity. Reading about a project called "Bush Demon", and then seeing that you would not ever want to actually build a bush type aircraft got me confused.

There are people here who I like to genuinely needle occasionally, but at present you haven't been granted that special lofty status :)

Besides, you're kinda interesting. "A-hole biker" and "an exercise in mental gymnastics"... in the same guy... cool ! :)
 

BJC

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Just remember though, a persons motivations to do anything are their own, I don't mind answering, but the a-hole biker in me almost answered "because I want to....".
Ultimately, we each do what we want to do, so I’m with you on motivation. However, the most common question here is not about motivation, but about intent, What is one trying to accomplish? That drives the discussion to the technical factors involved.
So, here lately I have been giving some thought to how to deploy the leading edge slats. I was thinking on use of a torsion arm and an electric actuator, just deployed and stowed? Any thoughts?
Look at the hinged, self-deploying slats on the Just Super STOL. Simple, effective and light weight.


BJC
 

Arkan

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There are people here who I like to genuinely needle occasionally, but at present you haven't been granted that special lofty status :)

Besides, you're kinda interesting. "A-hole biker" and "an exercise in mental gymnastics"... in the same guy... cool ! :)
you think that is interesting, two years ago I gave up a 23 year career as a truck driver to go into healthcare. I work as a phlebotomist at a Hospital in northwest arkansas. The pay sucks, but at least I am home now. I made the decision due to being diagnosed with Type 2 diabetes, with meds and diet I have it under control now, but found on the road, it was next to impossible to control my diet. Since then I have lost close to 35 lbs, I don't have to take blood pressure pills any more, and my A1C is well under 7... now if we can just figure out why I am anemic. Hopefully it is just a bleeding ulcer, and not something more serious.

As for the special lofty status, I will just have to try harder... lol
 

Arkan

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This one of those times I wish I had unlimited funds, been looking into specs on engines. I wish I had the money to buy each of the smaller light sport engine options, dyno each, and run a durability test on them then publish a report. Getting real world info would be awesome. Line them all up on a stable immobile frame and run them at take off power with the props attached until they failed. Would be interesting to see the results. How much real world power they produced and how long they ran.
 
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blane.c

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because it is a challenge. In RC' s I have designed and built fast planes, acrobatic 3D flyers, piper and Cessna look alikes, and delta wings. Problem with RC building is this, I can take any rc plane, slap a larger motor on it, increase the control surfaces, and make it fly. Hell I took a flat piece of square foam board, added vertical uprights, cut in Eleverons, glued a wooden motor mount and a quad motor and flew it. The principals of flight are the same, weather your flying RC or real planes, but rc materials are so light, with a bad design, you add enough power and you can still make it work.

STOL planes I felt would challenge me, stimulate my problem solving skills, and make me think outside of the box. Also, I would love to live somewhere that a STOL would be a practical choice, but here where I live, no they would not be. Since I don't have a pilots license, and don't have the funds to build a plane, why not design something that is challenging, something I respect, and take the enjoyment and mental challenge.

VB, you have a lot of knowledge, and are the argumentative type of person I like, you make people think. Just remember though, a persons motivations to do anything are their own, I don't mind answering, but the a-hole biker in me almost answered "because I want to....". Nothing but respect for you, and please keep challenging me to think, that is my purpose on here, and with the design I am working on. Just remember we all have free choice, and why someone is doing something Ike this is their own reason, don't question their motives, question the the design, question the technical aspects, but don't question why..... when I am finished with this design, my goal is to have a set of plans I could hand to anyone, and they would be able to build one hell of a STOL plane. Maybe if I could win the lottery, I could build it one day. Who knows what the further holds,

So, here lately I have been giving some thought to how to deploy the leading edge slats. I was thinking on use of a torsion arm and an electric actuator, just deployed and stowed? Any thoughts?
Look at the Helio Courier, very successful plane and has spring loaded slats, aerodynamic pressure pushes them against the wing. I have heard that in a crosswind sometimes the downwind slat stays out longer but most common opinion is just land into the wind (the landing is so short) about the only time it is a real problem is on floats landing in a river with a strong crosswind.
 

Tiger Tim

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So, here lately I have been giving some thought to how to deploy the leading edge slats. I was thinking on use of a torsion arm and an electric actuator, just deployed and stowed? Any thoughts?
Design them right and they’ll deploy and stow themselves, meaning you don’t have to deal with the weight and complexity of any sort of actuators. What happens (roughly) is as your angle of attack increases your centre of pressure moves forward and the high pressure stagnation point at your leading edge moves down/aft. Either the low pressure can suck your slats open or the high pressure can push them open. In cruise flight that high pressure on the leading edge pushes your slats closed.

At least, that’s sort of the ‘folk aerodynamics’ view of what’s happening.
 

Arkan

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Okay, another issue, we'll two actually... one is folding wings, I worry that you lose strength at the wing connections to the fuselage with that design verses building them solid to the plane. But being able to fold the wings makes transporting the plane over the ground easier, but a fixed wing would be stronger..... thoughts?

second thought is on engines. A Harley twin cam 103 CI can produce up to 130 hp at 4500 rpms. Replacing the Harley primary drive with a custom made chain driven PRSU. Using the pulse compensator, should prevent pulse vibrations to the prop. They are fuel injected, air cooled, and would be easy to mount an oil cooler... all the engine data I have been researching is driving me batty, and I know Harley engines better than any other motor out there.... just a thought, but may not be practical or even possible. (Honestly the thought scares me that it could actually work.)
 

Arkan

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Reality is few use folding wing to advantage. Mostly it is an "idea". The Harley thing is likely not practical because there are simply better choices.
thank you for the information, and honestly I didn't think the Harley idea would work, but you can't help thinking about it. If I ally found a happy Zienth Crusier own happy with a Viking engine. He says he has over 300 hours on his with no issues. I am still Leary though, from talking with him, I gather he is a friend of the owners. Our conversations revolve around design and performance, and he keeps telling me to talk with Jan cause he is competing in STOL comps now.
 

blane.c

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With the VW engine thing (like Viking) I have no dog in the fight. But I would trust anything "Pops" on HBA has to say about them as gospel.
 

Arkan

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The Miller Lightplane used a homemade reduction on a Harley, saw it at Wheels Through Time in Maggie Valley NC.
I would love to know what kind of performance he got from it...
 

TFF

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You don’t throttle back an airplane engine as much as you would normally a bike or car. Your Harley needs to run 3800-4000 all the time. 2500 rpm would be descending to land. Set it up to run hard all the time. The little museum piece is probably 30 hp on a good day and was not worn out from use.

The illusive folding wing road plane is probably the hardest design to make work. Everything else is easier to do. Folding is mostly clunky, heavy, and multi person ground crew with a dose of I hope it all hooked up right and is tight. Over the road is hard because of strength. Strength is weight. An airplane is much more fragile than any car. It’s not designed to take road pounding. The strongest airplane is probably only a 1/4 as strong as a road car. How do you make it 3/4 stronger and not be 3/4 heavier? To an airplane, contacting the ground is a necessary evil. They do much better in the air.
 

Pops

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With the VW engine thing (like Viking) I have no dog in the fight. But I would trust anything "Pops" on HBA has to say about them as gospel.
And I will take anything Hot Wings says about them on HBA as gospel.
 

Arkan

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Well I live in Westville Ok, due Due Wedt of Fayetteville, just across the state line.... he isn't an CFI is he?
 

Arkan

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You don’t throttle back an airplane engine as much as you would normally a bike or car. Your Harley needs to run 3800-4000 all the time. 2500 rpm would be descending to land. Set it up to run hard all the time. The little museum piece is probably 30 hp on a good day and was not worn out from use.

The illusive folding wing road plane is probably the hardest design to make work. Everything else is easier to do. Folding is mostly clunky, heavy, and multi person ground crew with a dose of I hope it all hooked up right and is tight. Over the road is hard because of strength. Strength is weight. An airplane is much more fragile than any car. It’s not designed to take road pounding. The strongest airplane is probably only a 1/4 as strong as a road car. How do you make it 3/4 stronger and not be 3/4 heavier? To an airplane, contacting the ground is a necessary evil. They do much better in the air.
that is what I figured on the folding wing, I honestly don't trust a folding wing. The strength issue scares me, and I know my luck, that's what would fail. As for that plane with the Harley engine, it looked to be aeither a knuckle head or a pan. So 45 ic max and I would say 30 to 40 hp... not much anyways depending how it was built. I just wonder how well it flew, etc etc..
 

Arkan

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Where in AR are you? A good friend is in Fayetteville, and there are grass strips, many with camping, all around that area.
I live in Westville, but work in Springdale just north of Fayetteville. So I am close.
 
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