Personal Helicopter

[Mario]

So, I've had an idea for the longest time about making a personal, miniature helicopter. I was doing research, and I found this video:

http://www.youtube.com/watch?v=7D31WGnKTUE" onclick="window.open(this.href);return false;
(Higher quality version here: http://blog.makezine.com/archive/2008/0 ... lifts.html" onclick="window.open(this.href);return false; )

And now I know it's possible!
I was thinking of a design just like this, with twin rotors to cancel the spinning forces of the other. Except, I was thinking of a backpack-like design.

There seems to be some kind of part holding the rotors. It looks like it's connected to the engine and provides two output shafts - each turning in opposite directions. Is this a custom-made/DIY part or can it be bought somewhere?

The rotors are another issue. Where can you get rotors like that?

What kind of engine is he running there? I was thinking a lawnmower engine would be acceptable for this task. Even though it was made to spin a grass-cutting blade, it could do the job if you don't use it at top speed a lot. It's difficult to tell from the video, but it doesn't look like a lawnmower engine, even though it's one of the youtube tags. (but you know, that means nothing.)
Technically, any engine could do the task if it can crank out enough RPMs.
Plus, all new lawnmower engines are vertical shaft.

[collinE]

i mad one of thes last year but sold be4 i took pictures.

You see things like this and dream of the possibilities. I'd love for someone to make a good one an make kits or a tutorial. I know nothing of that sort of engineering so you be the first and tell us how.

[Triton]

lawnmower engine wouldnt provide enough power to produce lift, most likely they are using a rotax aircraft engine making someting like 70-100hp and there are a lot of rules as to what would and would not qualify as an ultralight. if its not an ultralight then you would have to get a pilots license to fly it lol

[vskid]

lawnmower engine wouldnt provide enough power to produce lift, most likely they are using a rotax aircraft engine making someting like 70-100hp and there are a lot of rules as to what would and would not qualify as an ultralight. if its not an ultralight then you would have to get a pilots license to fly it lol

I think the one the Mythbusters made a few years ago used a rotax engine (it rings a bell, at least). That episode would be a great place for you to start. Like Triton said, its not so much the RPMs that you need (a gearbox can change that for you), its the horsepower.
Its a great dream, but it probably won't come true unless you have a lot of money, time, and skills. Even if you do build one, you probably won't be able to do the things you want to do with it (either because of the machine's limitations or regulations). An autogyro seems like it would fit the bill, be safer, and do what you imagine a personal helicopter can do.