Hurricane 550 on 4S

[Kepler]

As much as I like this size heli I am also very keen on having a closer look at the next size down, say 420mm blades, 4C pack, and around the 1500 grams all up flight weight. So rather then going out and buying a complete new heli, I thought I would look at shrinking the Hurricane to see how it would go.

Using bits and pieces I already had, I carried out the following mods.
Short Boom conversion
425mm blades
Mega Power 3545 MN 1100 kV motor rated@ 900w
16 tooth pinion.
Hyperion 3700mah 4C pack

All up weight came to 1900g so it’s no light weight but this setup is only for proof of concept before I get serious with the weight reduction.

First flight was better then I thought it would be especially in relation to duration. Performance was mild but still capable of loops, rolls and a few flips to inverted. The big surprise was flight time. With a head speed of 1800 rpm, I managed a 7 minute flight without a problem.

So now to decide if the concept is worth perusing. Stripping off 400 grams is the big challenge and perhaps a little ambitious. Also need to get the head speed up a few hundred rpm. I have blinged up my current machine so much that I would only need to spend about $100 on parts and I will have another airframe to play with. I think I will get a few more flights first.

[pjones]

Nice work,

To save some weight with your current setup, you could look at smaller lighter servos, but I guess it depends on how much you want to spend, I don't have any to test but the plastic head might be a bit lighter than the cnc one??

I like the flight time and the cost saving potential with batteries. I will be watching for more results.

Regards

Paul.

[kgfly]

440g is a lot to try to lose. Candidates include:

* Ditch the Rx pack and run a BEC directly off the main flight battery (easily save 100g)
* Plastic swash, head, tail, anti-rotation guide etc (another 100g at a guess)
* Lighter servos (as Paul suggested)
* Lighter gyro (eg L2100 = 10g vs 401 = 28g)

Hard to see many other opportunities to save. You might find a couple of spots to drill out the frame but I doubt you would save more than a few grams that way.

This will be fascinating to watch, thanks for sharing your experiment.

[ukgroucho]

... shorten every wire that you can to it's minimum length. Another 10 or 20 grams.

[bcritch]

Maybe......

-ditch the wire wrap
-loose the rubber stops on the landing skids
-maybe cut the boom supports down a couple of inches
-go plastic with the head
-Is the canopy Fiberglass or Plastic, I think the plastic ones are a little lighter, but do not quote me on that, but its something to look into.
-I must agree about smaller servos, standard servo weight is about 45g, as where a HS-81 is 19g.

I know you said you have budget, some of these things that I have said as well as other have said are cheaper than others, but I think they are all worth looking into, please let us know what you come up with because I am interested in how this will turn out.

[Mikej]

Smaller servo wheels / arms
Smaller ESC
Smaller motor
Smaller Rx ?

[Pinecone]

You still have a big heli with short blades.

Better to buy a smaller heli. Quick of Japan EP8, Lepton, upcoming Trex 500.

[Kepler]

You are probably right but worth investigation considering all the parts I have left over after blinging up the current machine. Looking at the pre release info on the Trex500, this has a flight weight of 1700 grams on 4S and also looks to quite big for a 420mm blade size machine. Realistically though, 1800 grams is about the best I am going to see without major modifications. Head speed is also too low with the 1100 kv motor and would be better suited yo 1400 kv motor.

But for entry level, it is viable setup especially if you already have 4S packs from other projects