NSR Nylon Brake Line

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TFF

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His plane is something similar to an RV 8 but his own design with Grumman folding wings. It would be great if he would bring back the build thread.
 

GESchwarz

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Ventura County, California, USofA.
The main reason I wanted to use Nylaflow is the ease with which I can snake it through the airframe. Plumbing it with aluminum sounds like a major project.

I'm thinking as long as it is protected from the heat and the sunlight the Nylaflow should be okay.
 

Dan Thomas

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Sep 17, 2008
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Context matters. Carts, ULs, Bush planes, etc are typically open wheel designs with short duty cycles and/or low energy requirements. RVs are typically heavier ( higher energy), frequently faster (again, higher energy), and the brakes are typically inside an insulated container (wheel pant).
And isn't the RV trike steered using brakes? Castering nosewheel?
 

Dan Thomas

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The main reason I wanted to use Nylaflow is the ease with which I can snake it through the airframe. Plumbing it with aluminum sounds like a major project.

I'm thinking as long as it is protected from the heat and the sunlight the Nylaflow should be okay.
As I mentioned earlier, check out the nylon air brake tubing. Go to a big-truck dealer's parts department, or a farm equipment dealer. The black stuff is most UV-resistant, but it comes in other colors too. Air brakes are critical systems, used on buses and big trucks at 70 MPH on crowded highways, and that tubing had better last for years running along the frame out in the sun and wind and snow and ice and salt and dirt, and in the hot engine compartment. It's way better stuff than Home Depot tubing. Go here: 90924 100 ft. DOT Approved Nylon Air Brake Tubing, 1/4 in. O.D., Black | Imperial Supplies

Scroll down and look at the technical specifications. Tell me if they're no better than the Nylaflow.
 

reo12

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Jan 15, 2021
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My Orion Aviation Falcon had Hager brakes with nylon lines. I was pretty disappointed with the brakes function. Squishy and able to run out of travel on the grip mounted brake lever. I changed to automotive steel
brake lines and only used nylon at the stick pivot. I was considering using all steel line by forming a coil in the line at the pivot to absorb movement.
 

Dan Thomas

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The working pressure as well as the rupture pressure is too low on the Nylon air brake tubing.


BJC
It works fine for a lot of lighter homebuilts. Working pressure of 150 PSI assumes a constant pressure, while braking is very intermittent. Burst of 1200 is way beyond most aircraft brake pressures, including a Cessna's. I had that tubing on my Jodel for 20 years without any problems. It held even when I used my park brake that could put an awful lot of pressure into the system.

But every homebuilder has to decide for himself.

Some of these specifications are intentionally conservative to protect the manufacturer. For instance, PEX water system tubing has a working pressure rating of 160 PSI at 74°F, lower at higher temperatures. I did a bunch of it plumbing my basement bathroom, and wondered about how well those fittings were gripped with those tiny little ridges on the fittings, so I made up a test piece a foot long, with a PEX plug in one end and a female pipe fitting in the other, both retained with the crimp rings as per usual practice. Took it to the shop and filled it with 5606 hydraulic fluid and connected it to my hydraulic test pump and gauge, and covered it with some rags to limit the mess when it let go. I pumped it up slowly, and at 910 PSI the tubing split. Fittings never budged. I stopped worrying about the basement plumbing. I showed that thing to the plumbing inspector and he took it back to the office. He said they all wondered just how good that stuff was.
 

Arno

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Nov 11, 2021
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The copper-nickle alloy is probably what I would use, except for the flex points. Weight is neglible.
 

Bill-Higdon

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Feb 6, 2011
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Salem, Oregon, USA
Some people are running a larger outer tube to act as a conduit for the actual brake line so if it has to be replaced you can in theory pull out the old 1 & push in a new one
 
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