Hello from Los Angeles

[Lock_jockey]

I'm a locksmith by trade but my true passion is engineering. One of my lifetime goals is to own a small helicopter. I love the idea of building my own ultralight single seat helicopter. I think I have the proper aptitude to build something like this, I'm very handy, have good background in MIG welding, gunsmithing built several firearms from scratch), machine shop both CNC and manual operation mills, lathes etc etc.
So anyway, I'm very interested in a single seat helicopter everything is still in the brainstorming portion I love the idea of cannibalizing a Yamaha Fuel injected engine from either a wrecked snowmobile or a bike that way I'd have the engine, instrument panel, radiator and some other useful parts like a gas tank, fuel pump and key ignition I could recycle. I'm still hazy on the differences between aviation grade engines and street grade. I understand they are "de-tuned" to have their HP lowered but, I'm unsure what that means; how are they being modified exactly.

I'm really inspired by the Mosquito single-seater helicopters, especially the people that have built single seaters from scratch.

 

[wolfy]

Good luck in your project, the yamaha engines were tried in a helicycle and found to be lacking in torque for helicopter applications.

wolfy

 

[WaspAir]

I I'm still hazy on the differences between aviation grade engines and street grade. I understand they are "de-tuned" to have their HP lowered but, I'm unsure what that means; how are they being modified exactly.

"Street" (automotive-type engines) spend most of their running life at low power with respect to the maximum possible rated power they could produce (nobody drives around the streets in a 400 hp muscle car using all 400 hp all the time). You might drive around for years at only 30% or less of max power with only brief and uncommon events when high power is demanded from your car or motorcycle engine. In contrast, aviation engines more typically run at 75% power as a routine setting, hour after hour and day after day, with frequent and fairly sustained 100% power demands. Designing for one environment or the other can have an immense effect on reliability. The de-rating you hear about helps with that issue, because a 400 hp automotive engine won't last very long if operated at 400 hp continuously, and was never expected to do so by the designers.

A piston helicopter engine will run at a very steady high rpm all the time, keeping the rotor rpm constantly where it needs to be for best flight performance and safety, whether climbing, cruising, or descending, and whether flying slowly or quickly. The power applied to the rotor will be reflected in the manifold pressure reading rather than rpm, and is controlled with throttle and rotor collective pitch settings. If one restricts the manifold pressure that can be used, and/or limits the time at which high mp is available, the engine can last much longer. Such de-rating is fairly common; you might have 5-minute limit, for example, to use 145 hp for take-off or other short term demands, and run at only 132 hp power otherwise, while the same engine might be capable of producing 180 hp in a different application. Operating limitations of this sort don't require any actual modification to parts. The idea is not to limit the power you can make but to limit the power you use.

 

[martin-av8r]

I'm a locksmith by trade but my true passion is engineering. One of my lifetime goals is to own a small helicopter. I love the idea of building my own ultralight single seat helicopter. I think I have the proper aptitude to build something like this, I'm very handy, have good background in MIG welding, gunsmithing built several firearms from scratch), machine shop both CNC and manual operation mills, lathes etc etc.
So anyway, I'm very interested in a single seat helicopter everything is still in the brainstorming portion I love the idea of cannibalizing a Yamaha Fuel injected engine from either a wrecked snowmobile or a bike that way I'd have the engine, instrument panel, radiator and some other useful parts like a gas tank, fuel pump and key ignition I could recycle. I'm still hazy on the differences between aviation grade engines and street grade. I understand they are "de-tuned" to have their HP lowered but, I'm unsure what that means; how are they being modified exactly.

I'm really inspired by the Mosquito single-seater helicopters, especially the people that have built single seaters from scratch.

Welcome Aaron

i think you are at the best place here on this forum to learn for all rotary wing stuff

i also think if you want to instal a yamaha on your small helicopter project

you need a turbo for the setup to work good

i also like very much the engineering aspect of the engine conversion and the machine building

 

[Lock_jockey]

My father always had a saying "don't reinvent the wheel" which I always took as don't try to re-engineer perfection so if the Rotax series is the best engine for a small single seater helicopter I'll probably be using that, in addition if I can purchase the critical components like the swash plate assembly and the transmission splitter I'll probably purchase those units the ultimate goal is to create a flying machine not prove I am capable of making every nut and bolt on the craft itself, I realize between weight constraints and wear constraints this is very different then say a homemade motorcycle.

 

[martin-av8r]

My father always had a saying "don't reinvent the wheel" which I always took as don't try to re-engineer perfection so if the Rotax series is the best engine for a small single seater helicopter I'll probably be using that, in addition if I can purchase the critical components like the swash plate assembly and the transmission splitter I'll probably purchase those units the ultimate goal is to create a flying machine not prove I am capable of making every nut and bolt on the craft itself, I realize between weight constraints and wear constraints this is very different then say a homemade motorcycle.

Interesting reply from your first post

 

[Sv.grainne]

Quite a shift!

 

[tadgyro]

Some people like to build, others like to fly. First I suggest going and spending money and time learning how to fly a helicopter
and after start building one if you really want to fly one.
I was there and I know.
Teddy