Test

Resasi

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Jul 2, 2007
Messages
7,832
Location
London/ Kilifi Kenya
Aircraft
Gyrs, RAF 2000/Mgni/Bnsn/Hrnet/Mrlin/Crckt/MT-03/Lyzlle AV18-A/Prdtor. Pax ArrowCopter
Total Flight Time
100+ gyro, 16,000+ other
Jeeze Wolfy, horses bikes and buggies on the ground, gyros or copters above, and those feral cattle are still a real handful to weed out and get moving into a bunch.

My Grandfather, and Uncles all did beef, and dairy, out in Kenya but the beef were handled differently, kept in herds and always had herders with them. I guess down under without the staff you have to let them go bush until time to herd them for sale, then its all hands to get the job done...and a tough job then.

Looks like every day was an airshow routine just to get the buggers move where you wanted them to go. Made my later jobs in aviation cream puffs. Earlier on working the rigs in Libya and bush charter in Africa were bit rougher, but hours of herding...you certainly earned your money there.
 

Kevin_Richey

Yamaha gyro...Oregon, USA
Joined
Nov 16, 2003
Messages
2,340
Location
US
Wolfy: Your prop on the 912uls, what make, diameter & # of blades?

You guys mustering have always had my admiration for how many hrs. spent & skills developed from doing so!
 

C. Beaty

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Apr 16, 2004
Messages
9,910
Location
Florida
Smooth rotor judging by the freedom from stick shake in the video clips above.

I can see why those critters would get mean and nasty, having to find something to eat in that scrub land. I guess they mean it when they say Australia is the second driest continent on Earth.
 

wolfy

Active Member
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Dec 19, 2013
Messages
419
Location
western australia
Smooth rotor judging by the freedom from stick shake in the video clips above.

I can see why those critters would get mean and nasty, having to find something to eat in that scrub land. I guess they mean it when they say Australia is the second driest continent on Earth.
Certainly a contrast to the footage I have seen of Florida Chuck, I reckon these cattle would die of shock if they were dropped in a Florida paddock. But to be honest there is a lot more feed than it looks on these videos, of the little bit of footage I have got there is not much footage of the good country.

Those rotors were pretty good really, not as good as the light rotors that have been on it but good enough. You may recall I'm setting up a new gyro with a round 4130 mast, I am hoping it will be at least as smooth as that last machine. I did the first hang checks yesterday and it's looking good, with a 7 degree mast and the teeter bolt pretty much aligned with the mast it should be a good thing. Ideally I would like to put some light tip weighted rotors on the new build, but we are down to one manufacturer in Oz now very good blades but not light.

wolfy
 

wolfy

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Dec 19, 2013
Messages
419
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western australia
Chuck if you remember our conversations regarding sweedish yoke's etc, My last post to you came across extremely arrogant.
My apologies mate that was not my intention, but rather was trying to say that I agreed with what you were saying. Sometimes hard to say via typing.

Cheers wolfy
 

C. Beaty

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Messages
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Florida
Wolfy, if you were arrogant, I must have missed it. Sorry
I’ve been to Oz, but just to the East Coast and must say it didn’t look all that dry but I realize how little rain falls on the interior.
 

Jazzenjohn

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Oct 9, 2004
Messages
2,863
Location
Milan Mich.
Aircraft
I've designed, built, and flown 4 different ultralight gyros. Amassing parts for a 2 place now.
Total Flight Time
400+
I have limited experience with round masts, but I found that the round titanium tubing I used was far more flexible that the square tubing (and also less damped) and I might suggest you make the seat angle attachment from the mast to the front keel a bit higher than with square tubing and also make it possible to adjust up and down a bit to allow for some frequency tuning. I made my 3rd gyro with a welded titanium round tube frame and would have liked to have been able to move that attachment for tuning. I believe optimal tuning will change for gyros as a result of rotor weights, rotorheads, and prerotators making total mass at the mast head different.
 

Georgi

Member
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Jul 30, 2004
Messages
338
Location
Woodland ,CA
Aircraft
gyro " Ultralight Bandit"
I have limited experience with round masts, but I found that the round titanium tubing I used was far more flexible that the square tubing (and also less damped) and I might suggest you make the seat angle attachment from the mast to the front keel a bit higher than with square tubing and also make it possible to adjust up and down a bit to allow for some frequency tuning. I made my 3rd gyro with a welded titanium round tube frame and would have liked to have been able to move that attachment for tuning. I believe optimal tuning will change for gyros as a result of rotor weights, rotorheads, and prerotators making total mass at the mast head different.
Hi, can you, please, elaborate a little bit on "far more flexible than the square tubing (and also less damped). Thank you. Georgi.
 

All_In

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Apr 21, 2008
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San Diego, CA. USA
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Piper Archer, Aviomania G1sb
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Not sure over 10,000+ logged FW, 260+ ultralights, sailplane, hang-gliders
I could watch your videos all day long. I suspect many would love to see musters at work.
Is there a chance I could post them on PRA's Youtube channel?
Two ways to do that I can give you a Dropbox link and you can upload them and I will put them on our page.
Or give me a link to your Youtube channel and I can capture them and then upload them to PRA's channel.
 

Jazzenjohn

Gold Supporter
Joined
Oct 9, 2004
Messages
2,863
Location
Milan Mich.
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I've designed, built, and flown 4 different ultralight gyros. Amassing parts for a 2 place now.
Total Flight Time
400+
Hi, can you, please, elaborate a little bit on "far more flexible than the square tubing (and also less damped). Thank you. Georgi.
Flexible as in how much the tubing bends for a given amount of force. Round tubing is the same in all directions and square tubing is stiffer along the faces or planes as opposed to corner to corner. The Titanium tubing I used was 2 1/4" x .058 wall and was more flexible for the same force as square aluminum tube is along the face. Much of it depends on MOI or simply diameter. Larger diameter with thinner wall is stiffer than smaller diameter with thicker wall for a given mass until buckling becomes a problem. Materials have different damping depending on shape and material condition. Damping can be thought of as the opposite of ringing. Something that rings when tapped is less damped that something that thuds.
I still think Titanium is an excellent material for a gyro, it just has different strengths and weaknesses that need to be taken into consideration in the design.
 
Last edited:

Georgi

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Messages
338
Location
Woodland ,CA
Aircraft
gyro " Ultralight Bandit"
Flexible as in how much the tubing bends for a given amount of force. Round tubing is the same in all directions and square tubing is stiffer along the faces or planes as opposed to corner to corner. The Titanium tubing I used was 2 1/4" x .058 wall and was more flexible for the same force as square aluminum tube is along the face. Much of it depends on MOI or simply diameter. Larger diameter with thinner wall is stiffer than smaller diameter with thicker wall for a given mass until buckling becomes a problem. Materials have different damping depending on shape and material condition. Damping can be thought of as the opposite of ringing. Something that rings when tapped is less damped that something that thuds.
I still think Titanium is an excellent material for a gyro, it just has different strengths and weaknesses that need to be taken into consideration in the design.
Thank you. I was not clear in my question. Sorry. I know the meaning of those definitions. I wanted to know how those properties manifested themself in flight. Your sensation as a pilot. "Stick feel"
 

wolfy

Active Member
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Dec 19, 2013
Messages
419
Location
western australia
I have limited experience with round masts, but I found that the round titanium tubing I used was far more flexible that the square tubing (and also less damped) and I might suggest you make the seat angle attachment from the mast to the front keel a bit higher than with square tubing and also make it possible to adjust up and down a bit to allow for some frequency tuning. I made my 3rd gyro with a welded titanium round tube frame and would have liked to have been able to move that attachment for tuning. I believe optimal tuning will change for gyros as a result of rotor weights, rotorheads, and prerotators making total mass at the mast head different.
Thanks John. My thinking with wanting to go to a round mast is like everyone else, I wanted it to be as flexible as possible. I wanted to keep my seat/forward brace as low as practical to let the mast flex, but never thought of making it adjustable to tune the frequency. That's possibly a very good idea. At one stage I had concerns about maybe my mast being too flexible, so I put it to Chuck. The way I read Chucks response was that there is almost no such thing as too flexible (in this situation) providing your not near the tube design limits. Maybe your method of tuning the frequency is needed after all, but maybe not so much for tuning frequency but rather to keep just within the limits.

wolfy
 

wolfy

Active Member
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Dec 19, 2013
Messages
419
Location
western australia
I could watch your videos all day long. I suspect many would love to see musters at work.
Is there a chance I could post them on PRA's Youtube channel?
Two ways to do that I can give you a Dropbox link and you can upload them and I will put them on our page.
Or give me a link to your Youtube channel and I can capture them and then upload them to PRA's channel.
Thanks John, your welcome to use them mate. I have no idea how to give you a link but my channel is just my name Jim Wolfe.
There is more videos coming as I slowly upload them.

wolfy
 

C. Beaty

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Apr 16, 2004
Messages
9,910
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Florida
Mast stiffness:

It is not so much a matter of tuning as it is of keeping the inplane resonant frequency of the rotor as high as possible and avoiding resonance at the rotor RPM. This requires both a soft rotorhead mount and high inplane stiffness of the rotor.

Bensen is partly to blame for the 2/rev problem as a result of necking the rotor down to a width of 2.5” at its center. Wide hub rotors such as SkyWheels have fewer problems with 2/rev vibration.
 

MilesW

Junior Member
Joined
Jun 30, 2012
Messages
57
Location
Western Australia
Aircraft
Sportcopter M912
Total Flight Time
1400+ Gyro
Bensen is partly to blame for the 2/rev problem as a result of necking the rotor down to a width of 2.5” at its center. Wide hub rotors such as SkyWheels have fewer problems with 2/rev vibration.
Chuck, been wanting to ask this for ages.

Why the neck down to 2.5"? Why the SkyWheels solution of putting the extra width outboard of the towers? Why not just a wider hub bar?



Miles
 
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