Rudder cable vs. plastic bushings

Just hooked up my rudder to the cables and rudder pedals this weekend. Pretty cool. That said, the first thing that I noticed was that the cables make a modest racket sliding through the bushings. Got me to thinking... over the course of time, is this an issue? Will the cable gradually wear through the bushings and perhaps rub against the alum. of the bulkheads? If so, is this just an annual inspection item to make sure that the steel and alum. never rub against each other?

Has anyone tried running the cable in a piece of plastictubing to give it added protection? Am I overthinking all this and worrying about nothing?

alpinelakespilot2000 said:

Am I overthinking all this and worrying about nothing?

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Yes.

(posting additional words because VAF forums has a minimum post length)

It is a valid question...

dan said:

Yes.

(posting additional words because VAF forums has a minimum post length)

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Dan is too quick and too young....

This has been a question for a long, ...longggg... time, and this 1996 matronics posting on "good tips" might help....

Another idea that you might find useful. I got this idea from Andy Bajc
from Lincoln, Nebr. He built a RV-4 that won, I believe, "best metal"
airplane at Sun & Fun several years ago. He put a plastic "cable cover"
over his rudder cables. This material comes in 6 foot lengths, $1.00/piece
(from old invoice) and is slit the full length. It snaps over the cable.
When you use this you eliminate possible cable wear on the snap-in bushings
and therefor will probably never have to replace them. It also makes things
quieter as you eliminate the "sawing" noise echoing in the tail cone. I got
this cablecover from:
West Marine, 1-800-538-0775 (order), 1-800-262-8042 (customer service)

Bob Skinner RV-6

Cheap and easy...
Is it really needed? ... NO
Is it worth while? ... YOU DECIDE...
I'm going to do it...

gil in Tucson.... and this question was even asked to me this week by a RV-9A I did a TC visit on...

Pretty "slick"

I put the sail cable covers on my rudder cables. They are somewhat difficult to put on. I used a bent 1/4" pointed rod to push into the (already split)sleeves ahead of pushing the cable into it. This helped to open the split for easier insertion...along with the help of a little Boelube.
I'm still building but I can tell you the cable action is very smooooth...and quiet!

Sam

And if that stuff jams up somehow you'll be a ticked off dude! KISS

Hey, that sawing noise lets you know everything's "working!"

I used the slit cable covers up near the front
where the cable ends would catch on the
verticals just to the rear of the rudder pedals.
It is a good fix if you have the pedals angled
and to the rear because of a short inseam.

As far as hearing a sawing noise, no way.
My RV is the LOUDEST airplane I've ever been in.
I closed the canopy the other day before putting
my headset on and was surprised by the creaking
noise at the low temperatures.

I won't do that again,
Tom

History

dan said:

And if that stuff jams up somehow you'll be a ticked off dude! KISS

Hey, that sawing noise lets you know everything's "working!"

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Dan... I think there is a 10+ year history on it being OK....

Check out the covers on your next trip past a West Marine store in LA...

gil in Tucson
...but used to live 3/4 mile from the Marina del Rey West Marine store...

Rudder cable guide

I bough some clear polycarbonate tube that was just large enough to fit through the existing guide holes and has an I.D. large enough to work the cable through (actually pull it through with a fish wire.) I ran the poly from the bulkhead by the rudder pedals back to the second bulkthead behind the luggage compartment. Works fine, looks fine and I don't have to worry about catching on anything.

Paul
N694BP reserved

dan said:

Yes.
(posting additional words because VAF forums has a minimum post length)

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Dan-You've got a lot more hours on yours now than most. How did your snap bushings and rudder cable look at your last conditional? Any noticeable wear? I'm guessing no, from your response, but thought I'd check. Thanks.

alpinelakespilot2000 said:

Dan-You've got a lot more hours on yours now than most. How did your snap bushings and rudder cable look at your last conditional? Any noticeable wear? I'm guessing no, from your response, but thought I'd check. Thanks.

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The wear wasn't notable. I'll be doing a condition inspection in a couple of months and will obviously yap back if I see anything notable. 1132 hours now and lots of rudder cycles...

I had those plastic cable covers on a sailboat I used to own. They were covering the shrouds (wires that hold up the mast). I don't know how long they had been on there, but they were brittle, cracked, and peeling off in chunks. Probably from sun exposure, though.

dan said:

And if that stuff jams up somehow you'll be a ticked off dude! KISS

Hey, that sawing noise lets you know everything's "working!"

Click to expand...

Which... it did on my RV-4. The plastic covers were relatively easy to overpower but it was REALLY annoying. I took those covers off as soon as I landed.

Cable inspection

Recommended procedure for cable inspection, per AC 43-13b latest version Uncle Sam has on the web, Par 7-149.
CABLE SYSTEM INSPECTION.
Aircraft cable systems are subject to a variety
of environmental conditions...
d. Close inspection in these critical fatigue
areas, must be made by passing a cloth
over the area to snag on broken wires. This
will clean the cable for a visual inspection, and
detect broken wires if the cloth snags on the
cable. Also, a very careful visual inspection
must be made...

We also use this inspection technique for safety and hoisting cables as installed in the factories I work with, thus covering the cables with plastic sleeves is prohibited. 90% of broken wire strands are found this way, the cloth will find broken strands your eyes miss. Always use the cotton rag or cheesecloth for the inspection, snagging skin is just no fun! Just another data point for somebody's decision process.

A different procedure is defined for nylon coated cable, I have no experience with these and can't comment.

Don't ask what sizes, cause I don't remember, but I snapped a smaller size grommet into the standard rudder cable grommets. I used a Zona saw to split the smaller grommets, slip them over the cable, then pop them into the larger grommet. It buys time so I, hopefully, can repair it before sawing into the bulkheads. So far,so good.

Roberta

And the WINNER is Roberta!

robertahegy said:

Don't ask what sizes, cause I don't remember, but I snapped a smaller size grommet into the standard rudder cable grommets. I used a Zona saw to split the smaller grommets, slip them over the cable, then pop them into the larger grommet. It buys time so I, hopefully, can repair it before sawing into the bulkheads. So far,so good.

Roberta

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Just got my RVator #5 today. Lo and behold there was and article addressing the potential for the rudder cable to saw through the snap bushings. In what now appears to be a Van's endorsed solution, the article written by another builder describes inserting the smaller SB437-4 bushing inside the stock bushing, thus providing more material for the rudder cable to saw through before reaching aluminum! Good job "predicting" Van's solution, Roberta!

Whaddayano!!! Just seemed to make sense to have more material to saw through. A good, sharp Exacto Zona saw cuts through so you can open them up and slip it over the cable. Otherwise the cable ends are too big for the little grommets.

Roberta