Tubular Fairleads

[mhorowit]

In another thread we see mention of "tubular fairleads -

http://vb.taylorcraft.org/attachment.php?attachmentid=4039&d=1249146508

Apparently just like the tubing motorcycle handbrake cables run thru.
Anyone else using these? Any reason I shouldn't ? - Mike

[Hank Jarrett]

Re: Tubular Fairleads

Brake cables (activated by feet) have to be designed to take pretty high loads. Remember your legs and feet carry around your full weight all day and can apply forces 5 or 6 times that. The tubes the cables run in have to be supported to prevent deflection when the cables are in tension so they don't deflect out of plane and reduce the tension on the brake levers. The cables and tubes also have to be able to take the wear loads of the cables rubbing on the inside of the tubes. Lastly, this is a functional mod and will require proof to the Feds that your "new" system will work OK and be safe.
You could put them in under the floor boards and considering almost NO IAs know what should be there, and get away with it, but I sure wouldn't. If you want to do it, do the analysis, build a prototype and test it, go through the paperwork to get the job done legally. Then share the STC with the rest of us. ;-)
Hank
By the way, talk to the FISDO FIRST before you do all that work. PITA when you completely prove your design and they still don't like it. Remember they NEVER "have" to approve anything.

[Hank Jarrett]

Re: Tubular Fairleads

By the way, my Nieuport 17 design uses the cable in a tube system. But it is experimental, and I may not build it that way after seeing some REALLY COOL hydraulic disc brake systems that will fit inside a set of wire wheels!
Hank

[Marv]

Re: Tubular Fairleads

Mike the 46 BC12D1 i had did not have dual brakes. but the brakes on it had cables and pulleys and worked fine. If i was going to use heel brakes i would try to go that route. If i was keeping mechanical brakes and was doing 337 etc. i would try to put heel brakes on it like a champ. They were on the ruder pedals where you could leave your feet on the rudder pedals and have your heel brakes on at the same time. That is real handy when landing in high crosss winds. Marv

[mhorowit]

Re: Tubular Fairleads

... The cables and tubes also have to be able to take the wear loads of the cables rubbing on the inside of the tubes. .

Hank - during b'fast I was rethinking the fairleads. I'd be adding more friction to the system, so I sort of rejected the idea. Thanks for the input. - Mike

[jCandlish]

Re: Tubular Fairleads

The pilot side fairleads on my '39 have ~2500 hrs on them and they are just fine. The passenger side was added in 2005. The originals were 1020 and attached to the frame each in two places. They are flared at the ingress and egress.

I'm not familiar with the pulley system, but I imagine that if you don't keep the cable tension just right, the cable could jump the groove. With the dual brake system there is more chance of that happening, 'cause one side will go slack with every application.

My t-craft is #1368. I wonder when they switched to pulleys?

[3Dreaming]

Re: Tubular Fairleads

Pre war had the tubes, and post war had pulleys. Tom

[Hank Jarrett]

Re: Tubular Fairleads

Pre war had the tubes, and post war had pulleys. Tom

Not sure that holds true in all cases. Both my 41 and 45 have the pulley system. If it was the standard at some point a lot of your work is done for you. Cable tension adjustment on the pulley system is critical for good brakes, but the cable jumping the pulley isn't a problem. On mine the mounting strap is close enough to the groove to keep the cable in even when slack.
Hank

[Ragwing nut]

Re: Tubular Fairleads

My Deluxe had the tubes and was the 6th to the last pre-war built. They work just fine, friction was not an issue

[NY86]

Re: Tubular Fairleads

.. The tubes the cables run in have to be supported ... so they don't deflect out of plane ....

Hate it when that happens!