Westland-Fairey Rotocrane HC4

[PR19_Kit]

All such aerodynamic foibles had been rendered extinct by the time the Rotocranes were built........... 

[jcf]

Airframe area under the rotary wing isn't as much of an issue with a tip-drive machine like the Rotodyne,
and the Z was going to have even more area under the rotor.

[PR19_Kit]

The Rotocrane has DOUBLE the wing area under the rotor, but it's a much bigger area rotor mind you. 

Or it will be when/if I manage to build it..........

[Old Wombat]

I reckon I'm going to have to take up Womblies idea of drilling and pinning the blades, three of them snapped while I was sanding them down. 

It'll have to be a VERY small drill......... 

Or a channel (maybe two), which you can then fill with a volatile-based putty or liquid styrene once the wire is in place.

[PR19_Kit]

I'll experiment with one of the broken ones and see what works best.

[JayBee]

Think of it as just an extended high aspect ratio wing and I am sure you will find an answer. 

[PR19_Kit]

Think of it as just an extended high aspect ratio wing and I am sure you will find an answer. 

I did, and I didn't..... 

Try as I might I couldn't drill into the broken ends of the blades, they're just too thin and they're curved as well so the drill bit comes out of the side of the blade. 

Current plans centre on cutting narrow slots along the blades for maybe 0.25 - 0.5 inch and supergluing fuse wire in the slot before gluing the bits together.

And then PSRing each joint of course!

This could take a while.

[kitnut617]

What I've done in the past is cut slots with my razor saw which are wide enough to slide some styrene card in vertically using a bit more than you need and as snuggly as possible. Once it's glued good, I then trim the card top & bottom to suit. 2mm card might be good for your blades Kit.

[PR19_Kit]

Hmm, that may be a better idea Robert, thanks. 

[kitnut617]

I think in woodworking termology it's called a biscuit joint. Only it would be vertical instead of horizonally

[jcf]

A I find a 60° diagonal joint is best for gluing thin material end to end, it gives you more
gluing surface. Combined with Robert's spline method, it would be quite strong.

[PR19_Kit]

Having gathered together all the bits and pieces I reckon I'd need for this job, I find I've only got FIVE rotor blades...... 

Where the devil has the sixth one gone?

I went back and checked the pic of them to see if I'd really made six, and I had. 

[PR19_Kit]

Piano wire is stiffer than fuse wire.

Yeah, I think I'm aware of that........

But it depends on what's available in the right size at the time what I can use.

[kitnut617]

Where the devil has the sixth one gone?

I'll experiment with one of the broken ones and see what works best.

Not this one is it ?

[PR19_Kit]

No, I've got 1/3 of that one, but the rest has vanished.

However I do have enough bits and pieces to probably make one complete blade, but it'll have 4 or 5 joints in it!