i don't know what to do

Alexia

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#1
as i said in another thread, i decided to build a plane over the winter. that's something i wanted to do ever since i was little and now i'm finally getting to it.
but my dad really doesn't like that idea because he's very concerened about the possibility that i might end up killing myself like that. he said he'd much rather see me build something else like a car or a hovercraft so there'd be less chance of me getting hurt if something doesn't work right. a while ago when i was telling him more about my plans i saw a tear in his eye and that's when i knew just how serious he was when he said all that.

now i don't know what to do. at first i thought he'd like the idea because it's a whole lot safer, cheaper, and legal than my previous ideas ([Removed for legally dubious nature]my vision for a perfect car that would cost a fortune to fit my criteria). i had to scrap all those ideas because i simply couldn't get the resources to do any of it, but i could easily get most of the things i need for a plane under a $1000 in total.

i really want to build and fly this plane but i also don't want my dad to keep getting stressed about me getting hurt. it makes me really sad when i remember how sad and scared he looked when i told him im being serious with this project
 
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Rob110

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#2
a home built aircraft will cost way more then $1000 not to mention your need for flight training before you can even try to take off. to build a predesigned (airworthy home built plane) is probably in the $20,000 to $30,000 range for a reliable kit. How about rebuilding a old car or pickup truck it will be safer and less expensive and I bet your Dad will help with the costs and the labour :)
 

ade

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#3
I meant to reply to your earlier post, but sickness and mood and stuff put me off; indeed, just as I'd have put you off building your own aeroplane.
Not that I've ever built one nor flown one, but I do have a bit of layman's experience of flight from my own experiments with gliders and a general interest in the engineering and nature of flight.

With that, I was going to include a few links pointing to microlights, not just as alternatives to cobbling an aircraft together, but because those who've made such things have already accounted for the issues at hand.
A major issue, even before you begin and going by your original post, is that of underestimating a couple of things: the time you'd need to build a flying machine and amount of power needed for controlled and sustained flight.
Timewise, as you'd be at the cutting edge of whatever materials and technology which you'd be using, it's highly unlikely that you'll be able to get something airworthy (by any minimum standard, nevermind legal) within a year. This, because of the amount of testing that'd be needed.
Powerwise, going by what's said on the microlight forums, you've grossly underestimated the needed power for take-off and safe and controlled flight.
The Wright's flight is debatable as a powered flight, so it's not a good idea to use that as a benchmark. Sure, there are plenty of other benchmarks from early flying machines that you could use, but death and injury were a part of making those marks.

It'd be a nice project to build an aeroplane from scratch, using only available materials, but it'd probably make more sense to build it as a radio controlled machine. (Hint, hint)

Other than that, another good project would be to build your own powered bike. If you go the electric route, you could also build a wind turbine to charge the batteries. Electric would also be the easiest way for two-wheel drive.
 

Alexia

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#4
a home built aircraft will cost way more then $1000 not to mention your need for flight training before you can even try to take off. to build a predesigned (airworthy home built plane) is probably in the $20,000 to $30,000 range for a reliable kit. How about rebuilding a old car or pickup truck it will be safer and less expensive and I bet your Dad will help with the costs and the labour :)
i did the math. if i build the whole thing like an oversized model i can easily do it under $1k.
rebuilding a car was my original idea but that would be over 10x as expensive. i had my eye on a 1964 DeVille but it was in bad condition and cost almost $5k, nevermind that i don't even have a single piece of proper equipment to work on it or the finances to keep its gas tank full. besides, my dad never had a cool car that he'd one day pass on to me. that made me really sad and is part of the reason i decided to forget about it and come up with something else.

A major issue, even before you begin and going by your original post, is that of underestimating a couple of things: the time you'd need to build a flying machine and amount of power needed for controlled and sustained flight.
Timewise, as you'd be at the cutting edge of whatever materials and technology which you'd be using, it's highly unlikely that you'll be able to get something airworthy (by any minimum standard, nevermind legal) within a year. This, because of the amount of testing that'd be needed.
Powerwise, going by what's said on the microlight forums, you've grossly underestimated the needed power for take-off and safe and controlled flight.
The Wright's flight is debatable as a powered flight, so it's not a good idea to use that as a benchmark. Sure, there are plenty of other benchmarks from early flying machines that you could use, but death and injury were a part of making those marks.

It'd be a nice project to build an aeroplane from scratch, using only available materials, but it'd probably make more sense to build it as a radio controlled machine. (Hint, hint)

Other than that, another good project would be to build your own powered bike. If you go the electric route, you could also build a wind turbine to charge the batteries. Electric would also be the easiest way for two-wheel drive.
i think you underestimate my abilities. the only time consuming issue is sourcing the materials and the only real issue is trying to find a propeller. seriously, it seems like it's impossible to buy a simple wooden prop anywhere.

for a powerplant i thought about one of those 20hp single cylinder gokart engines. it has enough power and light weight (not to mention low price) so i can't see why it wouldn't work.

the whole thing being illegal is absolutely the last thing i care about. i mean, i don't care about that at all.

i already built an RC model when i was 12 and once i figured out how to get it in the air with its underpowered stock motor i flew it like it was nothing. keep in mind, that wasn't one of those toys that uses differential thrust steering. it was an actual model with 100cm wingspan, elevator, rudder, and ailerons. if i was able to fly that underpowered model on my first try without any training at the age of 12 then i should be able to fly a real plane. after all, laws of aerodynamics are exactly the same for a small model and a huge jumbojet
 

AnalogRTO

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#5
i did the math. if i build the whole thing like an oversized model i can easily do it under $1k.
rebuilding a car was my original idea but that would be over 10x as expensive. i had my eye on a 1964 DeVille but it was in bad condition and cost almost $5k, nevermind that i don't even have a single piece of proper equipment to work on it or the finances to keep its gas tank full. besides, my dad never had a cool car that he'd one day pass on to me. that made me really sad and is part of the reason i decided to forget about it and come up with something else.
I can agree with you about the cost of a car. I'm rebuilding a '31 Chevrolet as a street rod in my garage that used to belong to my wife's grandfather. The car was $9k (had to buy at auction to support her grandmother being in a home), engine and transmission was $5k, rear end was $3k, wheels alone will be another $3k...I'll be into this thing for probably $40-50k by the time I'm done.

With that said, don't think you can build a plane like an oversized RC model. Engineering and physics does not always scale in a linear fashion, i.e. sizing up beams to 10X larger does not mean they can handle 10X the load. I have formal engineering training, please understand I am not speaking off the cuff. I have had classes in statics and dynamics, thermodynamics, and that is the limitation of my mechanical engineering and I wouldn't try taking on building a home-brew aircraft because I know the challenges and difficulties. If you have all the aerodynamics engineering training needed to design an aircraft from scratch, then I won't tell you no, but I have yet to see any information that indicates you understand the magnitude of your undertaking.
i think you underestimate my abilities. the only time consuming issue is sourcing the materials and the only real issue is trying to find a propeller. seriously, it seems like it's impossible to buy a simple wooden prop anywhere.

for a powerplant i thought about one of those 20hp single cylinder gokart engines. it has enough power and light weight (not to mention low price) so i can't see why it wouldn't work.

the whole thing being illegal is absolutely the last thing i care about. i mean, i don't care about that at all.

i already built an RC model when i was 12 and once i figured out how to get it in the air with its underpowered stock motor i flew it like it was nothing. keep in mind, that wasn't one of those toys that uses differential thrust steering. it was an actual model with 100cm wingspan, elevator, rudder, and ailerons. if i was able to fly that underpowered model on my first try without any training at the age of 12 then i should be able to fly a real plane. after all, laws of aerodynamics are exactly the same for a small model and a huge jumbojet
Your abilities to build something is not something I am going to call into question. What bothers several of us is that you haven't given indications that you understand the implications here. Getting a propeller isn't hard--a carbon fiber model would likely be your best bet as wooden props are heavier and require a lot of work from the manufacturer to make one that can handle the stress without blowing apart. Even with that, you'd probably be looking at a minimum of $1k for a prop (look them up online, they can be had).

For a powerplant, I don't think 20hp will do it for anything beyond an ultralight aircraft (i.e. powered hang-glider with a seat under it). A full aircraft will need a lot more power just to overcome the additional drag of it's size, generate enough speed to get the lift needed to get airborne, etc. The Wright Brothers were able to get their plane in the air because it had massive wings that were basically fabric stretched over the smallest skeleton of wood. They didn't get enough speed to stress the airframe to breaking point. They still risked their lives getting it in the air.

As for legality, there's a lot you can do in the ultra-light arena without needing much government oversight. Still, if you want to get a full aircraft built and try to find somewhere to get it off the ground, good luck. Be prepared to faces fines, arrest, confiscation of your craft, and possibly jail time for going against the rules. Those rules are in place to protect the public, not you. I'm a licensed skydiver, I can't just jump into any given location on a whim (exiting aircraft due to emergency is a different matter). There needs to be a NOTAM (notice to airmen) filed to let other aircraft in the area know that jump activity will be taking place, and most places not designated as drop zones will require several million in insurance coverage to give you permission to land there to cover you possibly hitting someone on the ground and injuring or killing them. I get zero coverage on my life. I'm only a couple hundred pounds of weight, imagine the damage a full-size aircraft can do.

You last paragraph is what gives most of us pause. Getting an RC aircraft into the air isn't a big deal. You run it into a few things or do some low speed crashes, no big deal. Getting something off the ground and flying it around isn't a big deal. Landing anything safely IS a big deal. Handling emergencies is important training. Early flight training teaches you basic control of the aircraft, takeoffs and landings, and emergency procedures. Navigation, communication via radio, etc. is all secondary. As a skydiver, 98% of our first jump course is recognizing and handling emergencies. Keep in mind that if you screw up a landing with an RC aircraft, it just cost money to repair or replace. You screw up a landing in a full size aircraft, you get seriously injured or die.

Yes, the laws of aerodynamics are the same for a small model as a huge jumbo jet. The laws of aerodynamics do NOT scale in a linear fashion from a model to a jumbo jet. Drag and the power required to overcome it is a major factor. Look at high performance cars--why is it that a 40hp engine can get an old VW on the freeway up to 75mph yet putting a 400hp engine in a car doesn't get you 750mph? Why is it supercars with well over 1000hp top out under 200mph? It's not a linear scale. Also, items that aren't major effects for small RC models (ground effect is one that comes to mind) are a real issue with larger aircraft. Get the education you need before undertaking a project like this, please.
 

Slomo

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#6
Instead of a plane, take a look at ultralight aircraft. Under 500 pounds and you don't need a pilots license, certifying, faa approval, or any of that. Plus, they are basically sit down hang gliders that can take off from most anywhere. And should the engine fail, you glide back down. It's also possible to build one for under $1000 in materials too.

Also, if your dad is so concerned for your safety then invite him to help you build it. If he has a hand in it (even just double checking your work) then he is much less likely to be concerned about the final product.
 

foxkits

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#7
An ultralight aircraft used cost sometimes around a $5,000 for a decent one.
All the bolts and components are aircraft quality you can't use just normal Nuts and Bolts.
The motor alone is like $2,500 and up and that is usually a rotax snowmobile motor with a gear reduction. At one time I owned and flew ultralights.
Then I switched over to motorcycles at one time they were cheaper to run and you can do a lot to them if you want to.
 

Alexia

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#8
i guess it was stupid of me to have any hope at all. every single one of my projects always ended up on a scrap pile because i never got the essential parts that were needed to make it work. this is no different.. i wanted to do such things ever since i was little but i never got anywhere with it. i watched documentaries about inventors and the amazing stuff they put together and always wondered how they manage to get all those exotic parts and materials that i can't find anywhere. i tried to make something of my own, i tried to improvise, but failure was all i ever got. maybe i'll just start drinking vodka again. that's at least something i can't fail at..
 

Llayden

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#9
i guess it was stupid of me to have any hope at all. every single one of my projects always ended up on a scrap pile because i never got the essential parts that were needed to make it work. this is no different.. i wanted to do such things ever since i was little but i never got anywhere with it. i watched documentaries about inventors and the amazing stuff they put together and always wondered how they manage to get all those exotic parts and materials that i can't find anywhere. i tried to make something of my own, i tried to improvise, but failure was all i ever got. maybe i'll just start drinking vodka again. that's at least something i can't fail at..
I already addressed this, and I'll address it again. If this is a passion of yours, or building anything that you desire, pursue it. Pursue your passion. But that pursuit begins with practical hands on knowledge and schooling. Seek formal training for your pilots license. Pursue your A&P (airframe and power-plant license). Go to school for engineering. You say you understand the project, but MANY of us are concerned that you do NOT.

I grew up surrounded by aviation. I always had a fascination for anything that flew and all things mechanical. When I graduated High School I went straight to the Air Force to get my hands on planes. I spent 14 wonderful years building, testing, maintaining jet engines on several airframes around the world. But that passion to build, design, and understand how things works was never extinguished. After an injury led to my exiting the Air Force I immediately pursued my engineering degree.

This has been a long, difficult path. And it has been exceptionally rewarding. NOTHING can replace practical experience and knowledge. You reference early pioneers and inventors as being able to accomplish so much with so little. What you don't realize is how many of those pioneers failed, or how many of them died in pursuit of that knowledge. Almost everything we know today came at an exceptional cost, and no one here wants you to pay that price.

I HIGHLY recommend looking into an engineering program, even at the associates level. If you truly have a passion to design and build, chase that dream.

I had as many ideas and dreams as you probably do when I was your age. My thoughts and ideas have only evolved and been refined over the years with the gained experiences and knowledge. I have always been able to imagine an object (machine, building, parts) so vividly in my mind. I could see it, manipulate it, and change it in my head. I could see all the dimensions and hold all the figures in my head. The first time that I was able to actually articulate that idea as a 3 dimensional model in a CAD program, build and test small models, and then finally manufacture a real part was....amazing. To finally see a real life, functioning product that I thought up, designed, calculated, drew, re-designed, and manufactured is an experience that I was not prepared for. It's magical. I want you to chase that magic.

Don't give up simply because people are trying to help you. You may not think that we (or your father) is helping you, but we truly are. There are many people on this forum that have many different experiences with all things aeronautical/engineering. Not a single one of us want to see you hurt. You absolutely can make your own aircraft, we just want you to do it correctly and safely.
 

AnalogRTO

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#10
i guess it was stupid of me to have any hope at all. every single one of my projects always ended up on a scrap pile because i never got the essential parts that were needed to make it work. this is no different.. i wanted to do such things ever since i was little but i never got anywhere with it. i watched documentaries about inventors and the amazing stuff they put together and always wondered how they manage to get all those exotic parts and materials that i can't find anywhere. i tried to make something of my own, i tried to improvise, but failure was all i ever got. maybe i'll just start drinking vodka again. that's at least something i can't fail at..
Therein lies the reason every single one of your projects fails. Don't give up on it. It make take time, it may take a significant amount more in terms of effort and education than you understand, but it can be done. Our concerns here are that you show a lack of understanding of the engineering and physics that are required to translate from a model airplane to a full size aircraft. Instead of stopping the project, tell everyone to go f*** themselves and get the education you need to do such a thing. Prove every single one of us wrong. It may not have to be a formal engineering degree, it is surprising just how far some people go without one. The two top engineers where I work never got degrees, and they can run circles around PhD-level engineers. I have a bachelor's degree and can hold my own against PhD-level engineers. What matters is the education and understanding and not giving up.

As I said before, I'm building a street rod in my garage. I'm an electronics engineer, not a mechanical engineer. I have had the required mechanical engineering courses to understand the stresses and strains on an engine, frame, and other parts of a vehicle. I bought books and learned how to go about this. My project will use a fuel injected 350 four-bolt main engine as the powerplant. I have NEVER messed with fuel injection before. So what did I do? I went and got a book on it and read up on how it works, what are the important parameters, etc. before I got into that area.

One last thing about all of this. Where I work, I'm one of the senior level engineers (my title is actually Staff Scientist). I didn't get to this level by getting my education and then just relying on that. I'm constantly learning new material. I do brand new designs on a regular basis. Many of them fail the first, second, third, and even fourth time. I learn why they fail and revise my design, eventually getting to a device that we sell as a production product. Considering parts I have designed were in the Spirit and Opportunity rovers on Mars, I'd like to think they work well. I've been at my job for nearly 25 years, and my designs represent more than a billion dollars in lifetime sales for the company. Success comes from not giving up, not from anything else.
 

Slomo

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#11
i guess it was stupid of me to have any hope at all. every single one of my projects always ended up on a scrap pile because i never got the essential parts that were needed to make it work. this is no different.. i wanted to do such things ever since i was little but i never got anywhere with it. i watched documentaries about inventors and the amazing stuff they put together and always wondered how they manage to get all those exotic parts and materials that i can't find anywhere. i tried to make something of my own, i tried to improvise, but failure was all i ever got. maybe i'll just start drinking vodka again. that's at least something i can't fail at..
This was literally the first google hit for $1000 ultralight. Yes kits can cost $5000 or more, and full size planes evwn more, but you've already said you want to build it yourself. Your idea isn't stupid, you just can't give up so easily when one or two people say it isn't possible. I guarantee you the Wright brothers had more than that saying flight was outright impossible. And they built their planes using bicycle parts, wood and canvas. I guarantee they did it for under $1000 too.
 
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