Regardless of the material you choose be certain that you use seamless
tubing.
There are three manufacturing methods used to make hollow shapes. The cheap
way is to form a tube from sheet stock and weld the seam (yuk!), a better
way is to extrude over a spider die which still has seams at the
microstructural level, and the right way for pressure applications is to
extrude the metal over a mandrel that is punched through the billet creating
a monolithic tube with no seam. Extruded tube is cold drawn to final size.
I used brass inside the fuselage and stainless steel on the exterior.
McMaster-Carr was my source:
Brass Tubing .085" ID, 1/8" OD, .020" Wall, 6' Length, P/N 8950K51
Type 316 Stainless Steel Seamless Tubing 1/8" OD, .085" ID, .02" Wall, P/N
89785K811
There were times while attempting to get the bends oriented correctly that I
doubted the wisdom of using rigid metallic tube rather than the factory
supplied, very flexible, easy to install plastic. Each time I questioned my
choice I remembered how my Lotus caught fire when the plastic hydraulic
clutch line ruptured and dumped brake fluid on the exhaust pipe, and my
doubts went away.
Buy extra lengths of tubing because unless you are an expert at tube bending
you will make mistakes.
...and Fred F. is correct that brass will work harden, but so does aluminum
and stainless steel. I doubt that there can be sufficient flexure to cause
a metallic brake line to fail (if the gear legs flex enough to fracture the
brake lines you've got worse problems to worry about).
Best regards,
Rob Housman
Europa XS Tri-Gear A070
Airframe complete
Irvine, CA
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com]On Behalf Of Alan Burrows
Subject: Europa-List: Brake Pipes
<alan@kestrel-insurance.com>
Has anyone got any better solution than the standard plastic pipes used
on the Trigear finger brakes. I am thinking of using copper is that the
best option or is there something better?
Many Thanks
Alan
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