Blades for Big machines

Fencing Wire · 22-12-2006, 10:29 PM

Hooray!! I was about to give the efferating computer a 12 gauge enema. Tried to post this 5 times, and each time it spat me out.

I went to the Nats at Lameroo in 98. What draws me to gyros is all of the ingenuity of the gyro-nuts. This machine belonged to a dude by the name of Henley-Smith (IIRC). Some of yer might ave herd of him

As I recall, the theory was that you could fly 1 up with 1 set of rotors, and 2 up with the pair. Even though he was in shakedown mode at the time, it seemed to fly pretty well. I seem to recall hearing that the things never took off because of the added expense (ie cost twice as much as 1 set of rotors). In todays climate of bigger, heavier machines, and consquently bigger rotors and more complex heads to compensate for shake etc, has this concept become more relevant? Anybody know anything? Anybody got thoughts?

russ · 23-12-2006, 07:30 AM

Contact jerry goodwin......sydney. He was trialling this system years ago.

Aussie_Paul · 23-12-2006, 11:05 AM

I saw that at Lameroo also Fred.

Ernie Boyette tried that quite a few years ago. They added weight after one flight and the blades went out of control and the pilot was lucky to get it down. I believe all 4 blades were cracked at some station out along the blade.

Try a search on the US forum as it may heve been discussed there. It was back in the days of Norms forum.

Aussie Paul.

SamL · 23-12-2006, 01:37 PM

mceagle · 29-12-2006, 06:17 PM

Many people have trialed this system Fred but they all end up going back to a standard blade system.
Probably a good thing too because the 'opposite ' set acts like an anchor for the rotor axis hindering the lead-lag action of the mast. A sure recipe for a cracked hub-bar or head.

Fencing Wire · 29-12-2006, 07:33 PM

Quote:

Originally Posted by mceagle

Many people have trialed this system Fred but they all end up going back to a standard blade system.
Probably a good thing too because the 'opposite ' set acts like an anchor for the rotor axis hindering the lead-lag action of the mast. A sure recipe for a cracked hub-bar or head.

Thanks Tim, That's what I was looking for. Figured there had to be a reason. When I think about it, its logical.

SamL · 30-12-2006, 09:42 PM

Quote:

Originally Posted by mceagle

Many people have trialed this system Fred but they all end up going back to a standard blade system.
Probably a good thing too because the 'opposite ' set acts like an anchor for the rotor axis hindering the lead-lag action of the mast. A sure recipe for a cracked hub-bar or head.

Tim what do you mean by (lead-lag action of the mast)

Sam.............

zeebo · 31-12-2006, 06:35 PM

Sam was that you flying along Torquay beach on saturday? Looked Bloody Awesome. Sybe.

SamL · 01-01-2007, 10:39 PM

Hi Sybe
It was, and was a bloody great flight to. Took off from Barwon Heads, flew to Lonsdale, Queenscliff,and then StLeonards AirPort. From there all the way back past Torquay and onto Anglesea then back.
Real Great place to fly from, and should be doing more now my machine is based there.

Sam.

mceagle · 02-01-2007, 08:02 AM

Quote:

Tim what do you mean by (lead-lag action of the mast)

Sam.

G'day Sam. The longitudinal centre of pressure of each blade varies cyclicly with rotation, being further out on the retreating blade than on the advancing blade, This creates a tendency for lead-lag in the rotor system that is partially compensated for by flexability in the rotors themselves and partly by the flexability of the mast. The more you restrict the flexability of the mast, the more must be absorbed by the rotors or hub-bar.