Question about 6061 tubes.

J.C.Casabuono

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I see that there are extruded 6061 Al tubes with "seam" and "seamless". Which ones are normally used to built gyros? or doesn't matter?
Thanks
JC
 

WHY

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Most, tubing with a seam, you can "feel" a slight ridge in the inside of the tube and once you find the ridge, you can look down the inside of the tube and see the seam and then see it on the outside when you know where to look.

Tony
 

Rehan K.Janjua

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Hello JC

If you dont see a seam inside or out, its seamless.
The seam can be very fine finish fuse wielded together.

Do you know Mr Edgardo Maffia, he built a gyro 10 years back.

Good Luck.
Rehan
 

J.C.Casabuono

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Hello JC

If you dont see a seam inside or out, its seamless.
The seam can be very fine finish fuse wielded together.

Do you know Mr Edgardo Maffia, he built a gyro 10 years back.

Good Luck.
Rehan
Hello Rehan,
I think that if the seam is visible, the extrusion is of very bad quality, but I understand what you mean.

Yes, Edgardo is a friend of mine, but his gyro was a Montalva of Brasil, welded steel tube frame...

Thanks

JC
 

Doug Riley

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What type of tubing are we discussing here? Extruded hollow shapes all have seams. The metal is squeezed through a die, like toothpaste. To make a hollow shape, a metal core must block the passage of the metal in the center of the extrusion. The core is supported by struts or fins that connect it to the rim of the die. The metal flows around the struts, forming seams. These seams are not weak spots if the extrusion is made correctly. They ARE weak spots if the extrsuion is poorly made.

Thin-walled round tubing is different. The seamless variety usually used in aircraft is not extruded, but drawn, like wire. The seamed variety is rolled up from sheet metal and welded. The welded type has a rough seam that is obvious on the inside of the tubing.
 

J.C.Casabuono

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Not always Doug, on the seamless extrusion, the center mandrel or core you mention is attached or goes thru the stem and a hollow billet is used.

http://books.google.com/books?id=KwN77NR1O8QC&pg=PA167&lpg=PA167&dq=aluminum+extrusion+seamless+tubing+process&source=bl&ots=uBDxdPW25U&sig=NLpoqaw4xoVEgRdl20LV_0LoH58&hl=en&ei=L9trTdT9IoOctwfZqpzmAg&sa=X&oi=book_result&ct=result&resnum=5&ved=0CDkQ6AEwBA#v=onepage&q&f=false

That the reason of my question, but I think that only work for round tubes...

http://www.astm.org/Standards/B241.htm
 

Aviomania

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steel tubes come in seemed ( formed from flat sheet and welded) and seamless types.

Aluminum are extruded!!!! ..... aviation grade thin wall are cold drawn after extrusion!!!
 

J.C.Casabuono

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steel tubes come in seemed ( formed from flat sheet and welded) and seamless types.

Aluminum are extruded!!!! ..... aviation grade thin wall are cold drawn after extrusion!!!
Let me clarify, i'm talking about aluminum extrusion, not about structural tubes formed from sheet metal and welded.

Please read this extract from Wiki:

http://en.wikipedia.org/wiki/Extrusion

There are several methods for forming internal cavities in extrusions. One way is to use a hollow billet and then use a fixed or floating mandrel. A fixed mandrel, also known as a German type, means it is integrated into the dummy block and stem. A floating mandrel, also known as a French type, floats in slots in the dummy block and aligns itself in the die when extruding. If a solid billet is used as the feed material then it must first be pierced by the mandrel before extruding through the die. A special press is used in order to control the mandrel independently from the ram.[1] The solid billet could also be used with a spider die, porthole die or bridge die. All of these types of dies incorporate the mandrel in the die and have "legs" that hold the mandrel in place. During extrusion the metal divides and flows around the legs, leaving weld lines in the final product.[4]

And also the links in my previous post.
 

Heron

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Hello J.C.
What is Edgardo doing these days? Tell him to drop by and say hello!
How can I get a copy of his Gyro Bible?
Gracias
Heron (Pelé is better than Maradona) :D
 

J.C.Casabuono

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Hello J.C.
What is Edgardo doing these days? Tell him to drop by and say hello!
How can I get a copy of his Gyro Bible?
Gracias
Heron (Pelé is better than Maradona) :D
Hello Heron!

Edgardo is a man with to many interests, he left the aviation now, sold the hangar and both gyros...he is working in his company and living the life ;)
There is a lady that sell The Biblia of the Gyros and other aviation stuff...Norma Sansone [email protected] 05411-4865-6985 80$ or around 20 u$s.

Pelé is better than Maradona because he has 3 legs!...:lol:

Abraço

JC
 

J.C.Casabuono

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Back to the question, can someone tell me which ASTM specification number is labeled on the square tubes used normally to built your gyros? tks
 
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