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control cable lubrication

Kroil

I knew an old mechanic who had a cable lubricainting contraption made from an automobile master cylinder. He saved a lot of sticky cables. His lubricant of choice was Kroil.
 
Most cables have Teflon liners, and don't need any kind of lube. I would only try this if the cable got sluggish. Which might take 20 years.
 
This is a neat tip if you have motorcycle or bicycle style cables -but I am not aware of any cables like that in most RV's. Certainly our standard engine controls aren't (they are the teflon-lined ones mentioned by Gasman), and this tool won't work on them.

Paul
 
I agree with Paul and Gasman, the only part of standard aircraft control cable that can benefit from a little lube is the locking mechanism in the cockpit. If the cable is getting stiff then most likely the teflon liner has started to wear through or has started to melt.
 
Huh. So the cable in the video is not a standard aircraft control cable and the video is all a bunch of hooey? How could they get it so wrong?

Erich
 
You may find some of those cables on "other" homebuilts or ultralights but I've not seen any on an RV. The cable in the video looks like the cable on my lawnmower and bicycle.
 
Control Cable Lube

The control cable being shown in the EAA video looks like some simpler bike or motorcycle cable. Probably nothing wrong with that application if it's installation and purpose are understood. You can see the stranded wire core in a couple close ups. Our closest variety might be the Bowden cable we get for carb heat and/or cabin heat. Simple, solid core wire.

The control cables we would get from Vans in the Firewall Fwd kit are manufactured by Tuthill Controls. Sorry, don't know how to put links up here, so Google it. I had a custom one built up from a local distributor for my RV-8 prop control. He showed me all the goodies that went into it. Plus they are "permanently" lubed at time of manufacture. It's on there web literature. The inner core is a more sturdy coiled steel cable. That's the part that slides back and forth. I don't think they suggest lubing their cables since they put this permanent lube in there.

I had one go bad when the plane was new. Barely 100 hours. It was routed too close to an exhaust run and distressed the end of one cable. The green stuff kinda melted. The only symptom was a very, very stiff cable. It was the mixture, and thankfully the bad travel direction was going to full rich from idle cutoff. Replaced the cable, changed routing a little, and put another heat shield on exhaust pipe. Good to go at 365 hours.

I know these little rascals have been called John Deere cables from past postings on all kind of RV forums, but when treated right, they seem to do pretty good. I would believe heat is their biggest enemy followed by bend radius. Post mortem analysis of my old cable showed good lube inside the outer sheathing, but all kinds of distress and delamination of the inner teflon liner in the area where the heat was put on it. That what started it binding up. Whew, I'm done. Time for a drink. Fly safe, fellows, please.

Jeff Liebman
RV-8. 365 hours on the Hobbs
Superior IO-360 Hartzell BA Prop
Airglades Airport, FL
 
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