I experimented in 1980 with a similar model with good results.

I used 4ft X 6" rotors turning in a 3ft radius. I powered it with a 1hp gearhead electric motor on a rehostat and by my calculations was lifting 10 pounds per horsepower.
The model was mounted on a long arm and sat on a scale so I could measure lift at different speeds.

My idea was to use a larger chord blade turned at low rpm for lift. The rotors were mounted at both ends and centrifugal force was not required to keep blades straight.

I was surprised how well it worked and how smooth it flew. Of course I thought I had come up with the worlds newest and best rotor system but with the advent of the internet I find many similar ideas were patented 70 years ago.

I went on to other things but have often considered building a larger tethered flight machine . All of the components are low tech and easily done by the home builder.

Great link Dave , thanks

Arnie Madsen
Bell 47 G2


Rotor Rooter

Dave Jackson
It sounds like it was an interesting project.

There was a US patent given to a large well-known company for some derivative of this idea a couple of years ago. Unfortunately, I can't remember the company's name or find the patent.

Did someone say Cyclocopter?

This is why I signed up for the forums. I started this little project a few months ago. Havn't gotten too far as far as putting anything other than a model together. But, I have been reading tons of reseach papers, and started learning some cad. Check some progress I've made.


Your in Houston, you should make it out to Anahauc one Saturday and visit us.
Mike484, I think i'l take you up on that offer. I've never seen autogyros in action. Should be pretty cool.

And yessir, and thank you Arnie, anything helps. The more the better. Do you think fabric on the airfoils is a poor choice for a cyclocopter? Given the kind of forces on the top and bottom of the airfoil blade.
If the hub diameter is also equal to the length of the airfoil. How do you get the length of the chord?
Draw a line from the front of your airfoil to the trailing edge and that is the chord line ..... the center of pressure on a rotor blade is usually about 25% Chord ( 25% back from the front of the airfoil) ..... that is where your pivot point has to be to change pitch ..... a very rigid blade is required for a cyclocopter model because centrifugal force is an enemy in this configuration .... that is why it should turn at a low rpm .... centrifugal force is a friend in the helicopter blade because the long unsupported blade needs CF to keep it straight ..... your blades have to also be perfectly balanced at the 25% chord pivot point otherwise your control linkages will be stressed or too hard to operate.


Gold Supporter
When I click the link it's says. "Sorry, the website cannot be found"
When I click the link it's says. "Sorry, the website cannot be found"
Sorry John ... I thought you meant my link .... the one that was in Daves first post is from 2008 and you are right ... it no longer works.

I have noticed all the good stuff on the internet has disappeared. Darn