My original idea for the Jeticopter was to have the 'copter ascend from ground level and stabilised by a launch rod sticking up out of a board. The copter has  a hollow rotor mast which threads onto the launch rod.

 

I tried this a few times but never had a successful lift off. I was wondering if, in fact, the hinged blades were not actually producing enough lift. Centrifugal force plays an important part in the operation and if the blades are not spinning fast enough the blades could simply cone up and then, because of the hinge angle, not have enough of a positive a angle of attack to generate lift.

 

In order to test this notion I decided to test with a set of blades with restricted cone up.

 

One of my aims had been to make a rotor head without metallic hinge parts. This arrangement uses the flex of the printed plastic to allow a bend on the required hinge line without the need for a metal hinge pin. I had come up with a design for this and printed it but the articulation wasn't sufficient to give the appropriate negative AoA for a controlled descent.

 

But, I figured, this would be good enough for the test I wanted to make.

 

So, I added my new 'stiff hinged' hub and set off to the flying field. 

 

 

In my new home I'm no longer fortunate enough to have the great flying field that features in my Jetex/Tendera video. Also, because I'm not currently driving, my scope for travel is restricted to walking distance and what I can carry.  But now I've found somewhere to fly. It's not huge but better than nothing. 

 

Now, one of the big advantages of the Tendera motors is the comparitive ease of preparation. The loading and fuse procedures of classic Jetex are rigerous and with two motors to manage something of nightmare compared to the ease of using the green fuse Tendera motors.

The procedure here boils down to:

-Install the motor(s) in the model. 

-Push the green fuse into the exhaust and you are ready to go!

 

Additionally, for twins like the Jeticopter, one wants both motors to light off pretty much simultaneously. By lighting the first fuse at its extreme end and the second fuse about halfway down a more simultaneous light off is possible. A better arrangement might be a two channel electric system but lets not run before we can crawl.

 

I'm using a disposable lighter for these attempts and I had problems getting the second fuse lit because of the lighter.  On my first attempt I got one motor started well before the second one. Not good. So, my first attempt with the stiff rotor head was not successful. 

 

However I reloaded and, with a new lighter had another go. 

 

I'd decided that with a hand launch I might at least get a sense of how much lift the rotor was producing. And I have a set of safety goggles so wearing these I felt happy hand launching. 

 

With the model on the ground the two motors lit off and then with the rotor spinning and holding the profile fuselage I lifted it up to launch height and then released.

 

I could feel a sensation of lift from the model and I released.

 

What then transpired was more of a delayed descent than a flight. With a gentle breeze the model drifted downwind and to ground level. It touched down and one wheel came off.  Then, something like a slow motion bounce occured and with both motors still burning the model ascended again to a little less than launch height.

 

One motor quit and with the rotor slowed down but still turning and with the model in an extreme bank one rotor grounded and broke off. 

 

Clearly we were getting some lift but not sufficient to counter the weight of the model. 

 

So, the next step is a weight loss exercise, for the model(!), to rectify that.

 

Was this a flight though? More like a delayed descent but still a little progress. I was pretty happy as I picked up the debris and headed home.