Gyro Tower materials:

First pilot

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May 27, 2017
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Windsor Canada
please comment on the use of 2" X 2" X .125 square corners as commonly used, 2" X 2" X .125 radius corners or double 1" X 2" X .125 All are 6061T6 Alum. An opinion from you successful builders would be appreciated.

Thanks,

tony
 

Jazzenjohn

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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+
I've had single 2x2 and double 1x2 square corner masts. I think the single mast is fine for light single place machines as long as you DO NOT drill a bunch of holes in it, Especially at neck height. I generally don't have any holes AT ALL in the middle, just at the ends. I wouldn't have a problem using the rounded corner tubing although I have never used it.
 

Brian Jackson

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Hamburg, New Jersey USA
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GyroBee Variant - Under Construction
In my limited experience building, a radiused corner tube will require any thru-bolts to be located further away from the adjacent tube wall by 1 radius, whereas a square corner tube will let the bolt exist .005" from the inside wall. The closer to the inside wall you can bolt, the greater the torque load can be because the tube wall is in nearly pure compression. Further away induces a bending moment at the corners. There may be other solutions for this I am unaware of. Also, bolts on both sides of the tube would be closer together (by 2 radii) in a round corner tube. Generally the farther apart bolts are the more secure the attached component.

I have seen photos of radiused tubes used in gyro construction but I do not know if any special internal reinforcement was used.
 

First pilot

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Joined
May 27, 2017
Messages
78
Location
Windsor Canada
In my limited experience building, a radiused corner tube will require any thru-bolts to be located further away from the adjacent tube wall by 1 radius, whereas a square corner tube will let the bolt exist .005" from the inside wall. The closer to the inside wall you can bolt, the greater the torque load can be because the tube wall is in nearly pure compression. Further away induces a bending moment at the corners. There may be other solutions for this I am unaware of. Also, bolts on both sides of the tube would be closer together (by 2 radii) in a round corner tube. Generally the farther apart bolts are the more secure the attached component.

I have seen photos of radiused tubes used in gyro construction but I do not know if any special internal reinforcement was used.
Thanks for your replies. I had intended to use 3/4' X 3/4" X .125 Angle outside the tube for bolting instead of drilling in the radius tubing. Maybe using 1/16' tubing on the bolts??. There is added weight with that in the hope of added strength.
 

First pilot

Newbie
Joined
May 27, 2017
Messages
78
Location
Windsor Canada
I've had single 2x2 and double 1x2 square corner masts. I think the single mast is fine for light single place machines as long as you DO NOT drill a bunch of holes in it, Especially at neck height. I generally don't have any holes AT ALL in the middle, just at the ends. I wouldn't have a problem using the rounded corner tubing although I have never used it.
Thanks, John.
 

First pilot

Newbie
Joined
May 27, 2017
Messages
78
Location
Windsor Canada
In my limited experience building, a radiused corner tube will require any thru-bolts to be located further away from the adjacent tube wall by 1 radius, whereas a square corner tube will let the bolt exist .005" from the inside wall. The closer to the inside wall you can bolt, the greater the torque load can be because the tube wall is in nearly pure compression. Further away induces a bending moment at the corners. There may be other solutions for this I am unaware of. Also, bolts on both sides of the tube would be closer together (by 2 radii) in a round corner tube. Generally the farther apart bolts are the more secure the attached component.

I have seen photos of radiused tubes used in gyro construction but I do not know if any special internal reinforcement was used.
Thanks for your reply, Brian. I do not like holes drilled in the tube. external angles are preferable to me.
 

wolfy

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Dec 19, 2013
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793
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western australia
Thanks wolfy. what wall thickness would you use? Are welded plates required for mounting engine mounts, head, etc.. or others??
I am not the expert mate, but on mine I used .065" wall with my single being nearly 800 pounds MTOW.
Mine uses bolted cluster plates and cheek plates with a kind of separate engine mount that is also clamped onto the mast.
I think ideally the mast will be bolted each end, and no bolt holes or welding anywhere in the middle.

wolfy
 

First pilot

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I am not the expert mate, but on mine I used .065" wall with my single being nearly 800 pounds MTOW.
Mine uses bolted cluster plates and cheek plates with a kind of separate engine mount that is also clamped onto the mast.
I think ideally the mast will be bolted each end, and no bolt holes or welding anywhere in the middle.

wolfy
Thanks for replying and contributing to the Gyro knowledge base.
 

Georgi

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Jul 30, 2004
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423
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Woodland ,CA
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gyro " Ultralight Bandit"
I am not the expert mate, but on mine I used .065" wall with my single being nearly 800 pounds MTOW.
Mine uses bolted cluster plates and cheek plates with a kind of separate engine mount that is also clamped onto the mast.
I think ideally the mast will be bolted each end, and no bolt holes or welding anywhere in the middle.

wolfy
Wolfy, sorry to steal your time, but can you provide pictures of all attachments to your round must. If you did it already, please, direct where. I have seen a few like this. but it takes more than "the average garage specialist"
 

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wolfy

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western australia
Georgi, I think there is some pictures in my build thread "the new gyro" but I don't really have any pictures of great detail sorry.

wolfy
 

wolfy

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western australia
My round tube is mounted very simply Georgi, Just 6 holes through the center at 3 o'clock and 9 o'clock with short bolts either side through the cluster plate and into gang channel nuts.
On the head it's the same but 5 holes the lower hole has a bolt right through tightened lightly (no crush tube) and 4 short bolts per side into gang nuts.
Somewhere on here Chuck did some drawings of this exact method, very simple construction.

wolfy
 

Georgi

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Joined
Jul 30, 2004
Messages
423
Location
Woodland ,CA
Aircraft
gyro " Ultralight Bandit"
My round tube is mounted very simply Georgi, Just 6 holes through the center at 3 o'clock and 9 o'clock with short bolts either side through the cluster plate and into gang channel nuts.
On the head it's the same but 5 holes the lower hole has a bolt right through tightened lightly (no crush tube) and 4 short bolts per side into gang nuts.
Somewhere on here Chuck did some drawings of this exact method, very simple construction.

wolfy
The rotor head on Chuck's gyro is very "close" to the central axis of the mast. I am thinking about the cheek plates flexing around a round mast when the rotor head moving further from the mast. I'll need to ask Chuck about it. From the other side, Wolfy, seeing what you put your gyro through...Do you use the "same" (like on square mast) 6061-T6 1/8" thick cheek plates? Thank you, Wolfy.
P.S. Found your gyro thread. Thanks.
 

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