Homemade Helicopter: For the People.

[icanbuildit]

Missing the point you say, being able to read a book, understand datum water lines, convert on computer, cut your fingers off and finish with one hand says something I am pretty sure. I have 4. GPA, can build anything and have, I'm not the guy who finished at Hardvardand never lifted a tool, but finished and can build my own house, not have to pay some one, then build this flying machine everyone thinks is so hard, gees?

 

[Mech_Engineer]

Missing the point you say, being able to read a book, understand datum water lines, convert on computer, cut your fingers off and finish with one hand says something I am pretty sure.

No, really, you DON'T understand. Helicopters are very complex (and potentially dangerous) vehicles. They have complex rotating parts that have to operate at high RPM's, and must be built of very light and strong materials. If you lost three fingers building a kayak, I shudder to imagine the consequences of an accident involving a heli's rotor

Despite your building houses, boats, racecars, whatever; none of these "proves" your worthiness. While I have to admire your "can-do" attitude, experts here and elsewhere will say you're out of your mind if you think building a functioning helicopter is anything close to these other projects you have worked on. You'd be much better off even trying to build a glider or ultralight (or auto-gyro) than what you are proposing.

I have 4. GPA, can build anything and have, I'm not the guy who finished at Hardvardand never lifted a tool, but finished and can build my own house, not have to pay some one, then build this flying machine everyone thinks is so hard, gees?

Despite your GPA (is that GPA in applicable engineering courses, btw?), I would give a Harvard graduate with a firm understanding of aerodynamics, control systems, and composite materials my vote... at least I hope he (or she) would know when they were in over their head...

 

[icanbuildit]

You guys are killing me, is there no faith unless you have some degree in building a rocket, did those guys just finish school or did they actually read a book, ask some questions, is everything you do certain, outcome always known, how many times has smoke come from some lab, test and trial. I would not presume to go strap a V8 to some pile of tubing made from the lawn mower. Books, lots of math, lots of questions but to think unless I am already an engineer I can't do, well that's just funny, everyone starts some where. How about instead of dogging me, give a man some advice besides trying to be as smart or giving up, I'd rather blow myself up than have never tried or say it looked good on paper but I just never had the balls.

 

[FredGarvin]

Missing the point you say, being able to read a book, understand datum water lines, convert on computer, cut your fingers off and finish with one hand says something I am pretty sure. I have 4. GPA, can build anything and have, I'm not the guy who finished at Hardvardand never lifted a tool, but finished and can build my own house, not have to pay some one, then build this flying machine everyone thinks is so hard, gees?

When you say "home built" do you mean a kit or one from scratch? Because if you're talking about from scratch then I would say you have a death wish.

 

[icanbuildit]

Good question, I have not seen anything worth building, I mean the nicer ones, best lines, engines lift and all, you might as well buy someone elses design. I think I would prefer to use the best as far as engine and controls but changes the over all appearance. I do not have the time or know how as most have said to do from scratch.
I would not buy a kit, right parts, right help, copter pilots I have known for years but desing my own yes. I woudl be man enough to say I am over my head but then again why build something easy?

 

[icanbuildit]

You stink, I will build it, prove simplicity, hard work and yes I will read up on engineering and see how many did it right the first time, (NOT) you should read history books now and again, not everything was made in CHINA, most all carved out of the hands of Americans.

 

[FredGarvin]

Anyone who knows what a dead man's curve is would tell you to rethink that.

 

[Mech_Engineer]

You stink, I will build it, prove simplicity, hard work and yes I will read up on engineering and see how many did it right the first time, (NOT) you should read history books now and again, not everything was made in CHINA, most all carved out of the hands of Americans.

There is no way you can "prove" the simplicity of a helicopter, because it isn't SIMPLE!

I know enough about the engineering of helicopters to know it can't be done (safely or economically) by someone who has no engineering background and no idea what goes into making one.

BTW, Fred IS an engineer that works on helicopters. If you should listen to anyone, it should be him.

 

[DaveC426913]

I am confident in saying that losing three fingers qualifies as a failed project in any sane person's books.

And in Icanbuildit's case, his future projects are limited: a mere 2.333 left.

 

[AKHS]

"Great minds discuss ideas; Average minds discuss events; Small minds discuss people." - Elanore Roosevelt---- Roosevelt also have a small mind, like me!

 

[Nijelboswell]

It all depends on how well it is built. If the Vehicle is impractically built, the flight will be disasterous. If it is practical with multiple mistakes, it will crash. There can be no mistakes on the building.
Perhaps if you are going to build your own Flying machine, Make sure you have it properly Examined and inspected. Get it Thoroughly checked...

 

[RonL]

Just to show that progress is being made.

http://www.dailymotion.com/video/x3pj1w_helicoptere-

 

[FredGarvin]

While I have a very hard time calling that a real helicopter, it is certainly some nice work. That's pretty neat. Do you happen to know if the controls are RC or if the person hanging underneath controls similar to the way an ultralight is controlled?

 

[RonL]

I believe it is all weight shift, and speed is controlled with the left hand. Counter rotating blades reduce the need for a powered tail rotor.
I think this falls under ultralite rules, so a 5 gallon max. will limit time of flight.
The link below is older technology, but also shows a possible area of personel transport, with high speed computer control, pilot input error can be eliminated, making this a very stable platform.

 

[Breadboard]

Again, not trying to brush you off, but have a look at some of the other threads about building go karts/hovercraft/planes in this forum and see what kind of level of detail you need to go into to do it yourself. Lots of people here have done engineering degrees, and many have years of experience behind them, but I doubt anyone here would feel confident designing something like this in its entirety, from start to finish, on their own!

I agree in principle, but disagree in general! Yes, building something like a small personal air vehicle of whatever type, would certainly involve a huge amount of work, and be quite expensive. But the parts and equipment are commercially available, and a design simply needs to incorporate the mechanisms of putting these all together. The most significant obstacle to overcome is the very strict regulations regarding airworthiness. The EASA regulations, even for small aircraft, are based around commercial, multi person craft, and do not reflect the needs and considerations of the small home builder because this was not a central concern when they were being drafted. The regulations I believe have also stifiled private aviation advancement for decades because the cost of design and research & development, in order to comply with the regulatory requirements, is outside the realm of the private inventor/builder. I'm not so sure about the FAA reg's. The entire market is drowned in very strict regulations which in some cases are very necessary, but in other cases could be re-drafted to be much more flexible, while still ensuring a reasonable level of safety. Complying with these regulations, and awaiting assesment at the various build stages is a major contributing factor to why home building takes so long.

Re. IcanBuildIT post's previously, and the replies. I think nobody is questioning the complexity of building a heli, however this does not mean it cannot be done with relative success and a reasonable flight safety level, by someone who is willing to spend time learning and 'carefully' building with attention to detail. Remember we are NOT talking about a heli with all the bells and whistles of a modern multi million dollar commercial design. Simply a basic design equivalent to decades ago. The first heli in 1907 was built by private designers unrestricted by modern limitations of technical and regulatory natures. It was still a 'helicopter' and it still flew...I wouldn't trust my life to it, but it worked. It can be done. People nowadays are blinded by the complexity that something can, but does not have to, have. There are two kinds of people...those who do, and those who talk about doing!

Didn't PM have ads for plans for a one man chopper. I seem to remember one type with jets/rockets at the blade tips.

If memory serves me correctly ( Which it may not! :uhh: ) the russians developed a heli using rockets at the tips of the rotor blades. I can't remember if there was a safety purpose, to assist in rotation of the blades after a main engine failure, or simply for powered assistance during takeoff/flight.

 

[RonL]

This page might be of interest to anyone thinking of rocket tip rotors.

http://inventors.about.com/gi/dynamic/offsite.htm?zi=1/XJ&sdn=inventors&cdn=money&tm=23&gps=574_1179_938_631&f=00&su=p554.2.150.ip_&tt=3&bt=1&bts=1&zu=http%3A//www.tecaeromex.com/

Look at tab "Isabel" and "rocket helicopter"

 

[RonL]

Tom Berry is near to having a back-pack helicopter that can be purchased in the future, details and price at this time are still unknown as he continues to test and improve it.
They fall into the ultralite category, which limits weight to 254 pounds, and a 5 gallon fuel supply.
The general agreement for power is 20-30 Hp, this at present, average efficiency will give around 45 minuets of flight time.

http://www.sporthelo.com/

I'm thinking he will show a better video soon

 

[Cyrus]

While I have a very hard time calling that a real helicopter, it is certainly some nice work. That's pretty neat. Do you happen to know if the controls are RC or if the person hanging underneath controls similar to the way an ultralight is controlled?

Looks like an utlra light heli to me!

 

[DaveC426913]

The video looks pretty straightforward for the first 33 seconds - a normal, if slightly robust RC heli.

And then at 34s I was absolutely gobsmacked to see that it has a seat. I did a classic double-take .

 

[FredGarvin]

Since he is pushing that under Part 103, I wouldn't trust Mr. Berry as far as I could throw him. I also hope that people understand exactly what the ultralight tag implies when it comes to what one can do with one.

Even looking at the "corporation's page", I can't find anything discussing the qualifications of the designers or the work they are doing. I would certainly hope that this isn't Cooter going out in his back yard and trying different things. It's a big leap to go from an electric stair chair and trailer mounted generator to an ultralight. I wish them the best, but to say he is near selling it when it appears that there has only been tethered flights is a big leap.

 

[RonL]

Since he is pushing that under Part 103, I wouldn't trust Mr. Berry as far as I could throw him. I also hope that people understand exactly what the ultralight tag implies when it comes to what one can do with one.

Even looking at the "corporation's page", I can't find anything discussing the qualifications of the designers or the work they are doing. I would certainly hope that this isn't Cooter going out in his back yard and trying different things. It's a big leap to go from an electric stair chair and trailer mounted generator to an ultralight. I wish them the best, but to say he is near selling it when it appears that there has only been tethered flights is a big leap.

I agree with most of what you are saying, the first link that i put in the thread does show a man in actual flight, and not a tethered flight. As for selling it to a mass of people, that's another thing, as an example, the GEN-4 Helicopter, made by a fellow in China is a well designed machine, the price of around 30,000$ US is very high, i can't find record of one sale going back to 2002, but there are lots of people that this amount of money is of no concerne. Untill a few machines are put into actual use, and at least some sense of safety established, there will be no market.
I think i like the Hiller Flying Platform best, with that you can have a parachute on your back.

 

[Breadboard]

Surely with the 80 pounds excess lift capacity alluded to on the page, incorporating blade jettisoning and a parachute assembly would not be impossible.

 

[RonL]

Surely with the 80 pounds excess lift capacity alluded to on the page, incorporating blade jettisoning and a parachute assembly would not be impossible.

There is a thread that discussed that a little, however that 80 pounds extra weight really puts a challenge in finding a power supply that can give the horsepower needed and at the same time not exceed the 254 weight limit (really a tight line here).

 

[morrijon]

What about a Homemade Helo without a swash plate?

I have a RC micro-helo that is naturally very stable, hovers by itself and has no swashplate assembly. It has a pre-set main rotor that adjusts lift merely by speeding up the rotor and it is naturally stable because of another mini rotor (not counter-rotating) above the main rotor that has weights on the end. I know nothing about physics but have been fascinated with the dream of building a "flying machine" of any nature. Why don't people build full size replicas of these things? Or maybe they do and I have never seen one. I can litterally throw this thing into the air, suddenly press the "accelerator" on the RC control and the helocopter rights itself from a mid-air tumble and hovers! Wow! To me that seems pretty full proof. I presume the mini rotor and weight system acts like a gyro to stabilize this very light weight contraption. I would add a small prop out the back that would provide forward thrust and the tail rotar would provide left/right turning. What do you guys think? Again, I am a total novice so I apologize if I said anything "obviously" stupid.

 

[RonL]

I have a RC micro-helo that is naturally very stable, hovers by itself and has no swashplate assembly. It has a pre-set main rotor that adjusts lift merely by speeding up the rotor and it is naturally stable because of another mini rotor (not counter-rotating) above the main rotor that has weights on the end. I know nothing about physics but have been fascinated with the dream of building a "flying machine" of any nature. Why don't people build full size replicas of these things? Or maybe they do and I have never seen one. I can literally throw this thing into the air, suddenly press the "accelerator" on the RC control and the helicopter rights itself from a mid-air tumble and hovers! Wow! To me that seems pretty full proof. I presume the mini rotor and weight system acts like a gyro to stabilize this very light weight contraption. I would add a small prop out the back that would provide forward thrust and the tail rotor would provide left/right turning. What do you guys think? Again, I am a total novice so I apologize if I said anything "obviously" stupid.

I have been looking, with a lot of interest, at some of these RC's.
The ones that have software which isolates the frequency of operation, so that you do not interfere with other fliers, i think is very good.
In the long run this might be a cheap way to learn about a helicopter.

 

[FredGarvin]

I have been looking, with a lot of interest, at some of these RC's.
The ones that have software which isolates the frequency of operation, so that you do not interfere with other fliers, i think is very good.
In the long run this might be a cheap way to learn about a helicopter.

They used to be replaceable crystals that were for a particular frequency. You just swapped crystals if someone was using your freq. They do it by software now, eh?

You do have to a bit careful with RC helicopters simply because they violate a lot of physics that the real ones have to follow. You won't ever find a real helicopter doing an inverted tail pivot.

 

[RonL]

http://www.hobbywarehouse.com/Products/RC-Helicopters/EFLH1250-E-Flite-Blade-CX2-RTF-Elec-Coaxial-Heli

This is what caught my attention, I'm not sure how the software eliminates interference,(detailed description) the model is small, thus not likely to do much damage

I have never been too excited about larger RC helicopters, because they look too much like my lawn mower at eye level, upside down and with no housing not sure why there has not been more severed heads in the world

 

[morrijon]

Micro-RC Helicopter

They used to be replaceable crystals that were for a particular frequency. You just swapped crystals if someone was using your freq. They do it by software now, eh?

You do have to a bit careful with RC helicopters simply because they violate a lot of physics that the real ones have to follow. You won't ever find a real helicopter doing an inverted tail pivot.

What laws of physics to these things violate? I am not sure what an inverted tail pivot is, but either way, I still don't understand why these things with relatively few and uncomplicated parts are so stable, when large helicopters are not? In other words, if I replicated my micro-rc helicopter to full size and figured out the specs it would need to be in order for me to "fly" it, it seems like it would be pretty full proof. (Relatively speaking of course). Of course, it wouldn't be a "real" helicopter with a swashplate and pitch changing blades and all, but who cares, it would hover, go up/down/left and right. It sure would beat those strange contraptions strapped to people's backs! Not only that, but it would need only simple electric controls to manipulate engine speed(s) instead of complicated hydrolics or heavy manual controls. The more I study this thing, the more I want to build it.

 

[Z-Abercrombie]

Hello, new here and found this to be an interesting thread. been interested in trying different designs in large scale RC helicopters and I have a couple of questions about counterrotating systems.

First is this: in a coaxial arrangement is it necessary that both rotors tilt or could the bottom one be left alone and all of the direction control be done with the top rotor(with yaw taken care of by airfoils like the airscooter and a few others)?
Second question is would the idea of having one rotor under the carriage (like the PAM 100b) and the other counter rotating one overhead be a stable platform? and if not why? If it is a legitimate option it would seem to really simplify the coaxial rotorhead issue by not having to worry about interfereing with each other.

Now for a quick intro: I teach high school Spanish but am fascinated by all things mechanical. Lately I have been playing with homebuilt cnc and hovercraft.

 

[mtworkowski@o]

Iv'e been looking at the comments on homemade helicopters. The problem is not that you can't build one. We built everything as kids and when something was impossible, we worked around it. The problem is that the learning process is very dangerous. You could be killed before you learn anything. You're not going to learn all the math and have all the lab equipment etc. So the way to build something is to pototype fast and dirty. Build a cheap prototype and test to destruction.
I think a really central part of the process is going to be the question of how we evolve designs from bad to good. Aerodynamics aside for the moment. We all know when something works beautifully or if something is wrong. The next question is whether it's going to work fine and then fail.
Get on it and don't listen to the naysayers. If you can't do it, you'll find out for yourself. Just learn the material and be safe.

 

[mtworkowski@o]

What laws of physics to these things violate? I am not sure what an inverted tail pivot is, but either way, I still don't understand why these things with relatively few and uncomplicated parts are so stable, when large helicopters are not? In other words, if I replicated my micro-rc helicopter to full size and figured out the specs it would need to be in order for me to "fly" it, it seems like it would be pretty full proof. (Relatively speaking of course). Of course, it wouldn't be a "real" helicopter with a swashplate and pitch changing blades and all, but who cares, it would hover, go up/down/left and right. It sure would beat those strange contraptions strapped to people's backs! Not only that, but it would need only simple electric controls to manipulate engine speed(s) instead of complicated hydrolics or heavy manual controls. The more I study this thing, the more I want to build it.

Yes, exactly. Why can't we scale up? Is it in the materials? Has anyone done the math to see if the weights and strengths are all in the right areas? Maybe a full size helicopter has to be made of carbon fibor and foam. I think the motor and drive line are too heavy in the full size. I don't own one of these RCs, but I bet a lot could be learn really fast by a few weights and measures.

 

[DaveC426913]

What laws of physics to these things violate? I am not sure what an inverted tail pivot is, but either way, I still don't understand why these things with relatively few and uncomplicated parts are so stable, when large helicopters are not? In other words, if I replicated my micro-rc helicopter to full size

Aye, there's the rub.

Scaling factors. Things that push the limits of mass, strength and power do not scale up very well.

http://en.wikipedia.org/wiki/Square-cube_law

It is the same reason why there are no humans sixty feet tall.

 

[FredGarvin]

Yes, exactly. Why can't we scale up? Is it in the materials? Has anyone done the math to see if the weights and strengths are all in the right areas? Maybe a full size helicopter has to be made of carbon fibor and foam. I think the motor and drive line are too heavy in the full size. I don't own one of these RCs, but I bet a lot could be learn really fast by a few weights and measures.

Yes. My company has done this in our applications. We got it to work, but, like the link Dave posted, it is not a direct/linear scale factor for just about everything. It gets much more complicated when things like bearing dynamics and fasteners are concerned. It also gets hairy when dealing with the aerodynamics. Some areas did scale well, but other areas were very difficult to scale.

 

[mtworkowski@o]

scaling up

In scaling up, only the intent can be scaled up. The actual form is dictated by the parameters of stregnth and weight. The construction of a violin is an efficient way to follow the parameters. Light, strong, does the job it was designed to do. Hot air balloon baskets is another example. Rattan because it's right for the job of containment, protection and resists impact shock. I mentioned carbon fiber and foam as examples of material that excel in certain areas. I'm also looking at the power plant to see what can be done with the weight. The old ways can't be used anymore. Fuels with cooler combustion temps. Cylinder walls supported by webs of material cooled with forced air. Something...

 

[mtworkowski@o]

Bravo