Another attempt, hover-copter

Little rotor - big prop

Little rotor - big prop

102 in (2,6m) is a very little rotor, but quite a big prop. Hopefully it is possible to make these blades homebuild with a reasonable good result in efficiency. That might open the door for building some low and slow rotor craft machines. We are seriously looking at copy milling a blade to get some experience. The job for the blades are:

50 hp into coax rotor for lift of 200 kg = 4 kg/hp.

App. figures for each rotor:
25 hp
Rotor dia: 2,6 m
Load 100 kg (Load per blade 50 kg)
Disk load 19 kg/m2

My current guess:
Rpm 850 = tip 34% of Mach 1 = 379 ft/sec = 115 m/s = 416 km/h
Upper prop 6 deg. (Angel measured to the flat bottom of blade.)
Lower prop 9 deg.

The alu blade is 180x22mm. We might shorten the wood blade to 160x22mm (6.3 x 0.87 in).

What do you think? Will it work?
 

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Ohh yes, thank you Zigge. In case I want to make a precise 3D model of the blade, the PDF might be helpful.
I already have 200 mm of a blade, and maybe I soon will get a longer peace app. 1,2 m.
Just bought some ash-wood 20 x 160 x 1300 mm. We will make one blade and take it from there.
 

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The Flying Sphere

The Flying Sphere

8 separate rudders. Might be a solution for a control system to an advanced HoverPlatform - no autorotation.

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The Flying Sphere - YouTube
 
Rotor blade profile

Rotor blade profile

I look forward to see what efficiency we can get from a homemade wooden PropRotor - meaning a Prop with a Rotor blade profile.
Also interesting to see what other problems we run into.
Hopefully we will get a lift to hp ratio of 4kg/hp=9lb/hp with a coax dia of 2,6m=8.5ft=102in and lift 200kg=440lb.

Looks very good what this Swedish guy has done http://www.peroxidepropulsion.com/article/33
We will do it in a very similar way as shown on these pictures:

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Build

Build

What a pleasure to have a build project again - I love it.

Pic 1. I bought laser cut alu plates.
Nice and easy when holes etc. are placed where they should be. A little expensive, but my garage is 8-9 hours (x2) travel away - so I need to plan according to that set up.

Pic 2. Precision work ;-)

Pic 3. 1, 2, 3 and the console for man, engine and drive shaft where well on it's way.

Pic 4. Here the console will be placed.
 

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Main frame

Main frame

I also got started on the main frame. Next week - after xmas - I will continue with the main frame.
Happy xmas.
 

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Main frame

Main frame

Main frame in one piece now.
Weight 17kg / 37lb. so far - that's fine.
App. 20kg / 44lb is the weight penalty for having the rotors below you.
 

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HoverKart

HoverKart

What a pleasure to have a build project. Due to this more friends have visited me and my garage the last days, and each of them have made some valuable input of one kind or another. Today I got the right name!
And as with a new born child... it might not be a howling success - but anyway I give it a name :D

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So, what have I been doing the last 6 weeks? One thing is enjoying my build project :D
And enjoyed talking to more people about different parts and sharing optimism for the project! But one factual thing is ordering a gearbox.

I have changed my mind about brackets for RotorProp-blades. I want them adjustable. The picture show the first design proposal - a simpler design is on it's way.
With such a bracket I can also choose alu extruded rotor blades instead of homemade wood RotorProp-blades. I hope very much we will have success with the wood blades... but I am a little sceptical myself.

Top one is with wood wedges. Button one is adjustable:
 

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I got my Italien Poggi coax gear today. Looks good.
Feels big so it should handle the job of converting the direction of app. 25 hp's.
 

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What a pleasure to do this first experiment! I am not terrible experienced with wood, so I really did not know how this would turn out.
But no doubt, this works and with no problems at all. Okay, it will take a little time and work with the equipment we use as it is just now.
Also, there will be much less grinding to do compared to what I expected.

A VERY PROMISING START :peace:
 

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Milling test completed. Result is pretty good - it can be done. The blade is neither bended nor twisted.
What the efficiency will be in the end is another story.

We will glue 2 layers of wood on the button at the root in order to give them more strength there.
We already loaded the blade with 25 kg. It gave quite some bending, but it did not break.
And we will make them app. half thickness at tip - by hand somehow.
Width of wood blade is 150mm/5.9". Thickness 19mm/0.75"
Width of Alu blade 180mm/7.1". Thickness 23mm/0.9".

The IVO props on the picture below is 84" and IVO have just informed that they sell them for $180 per blade.
I still need to get confirmed that I can load them with 50 kg each. I might have one more alternative here.

But it definitely would be much funnier to make and use home made wood blades.
 

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The blade production are in progress, and I start to be happy with wood. So the plan have changed (again). The current plan is seen on the picture below.
Upper rotor-prop dia. 102"/2,6m, lower 94"/2,4m.
You might be skeptical here - so am I - but it is a true pleasure to give it a try.
 

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We got 2 adaptor-bushings made, and then the hole drive shaft could be assembled - great!
Last picture shows a solution that is fine for a hovercopter, but not so fine on a helicopter - I think. (Gear shafts ø24 mm and hubs dia. ø30 mm)
 

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'Battery test'...

'Battery test'...

1x 20 kg :D
2x 20 kg :)
3x 20 kg :eek:hwell:
 

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Jens- I love your template following router jig. Very nice and thanks for posting that. Stan
 
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