I purchased my RV-12 and am doing my 1st C.I. and see that the rudder cables are so slack, unless the pedals are depressed, that the cables rest on at least two of the bulkheads in the fuselage. I've read some of the comments on this forum and most don't have a problem with the cables being slack, especially since some RV fliers tend to keep their feet on the rudder pedals while flying. I don't always keep my feet on the pedals. Therefore, I'm concerned about wear to cables and the bulkheads. I did not see a post where someone indicated their cables rested on the bulkheads. I'm tending to think that I need to at least check the length/hole spacing of the cable links and if not correct, re-tension the cables by revision or replacement of the links to get these cables off of the bulkheads. Comments are welcomed and appreciated.
Van's Air Force
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Rudder cables resting on bulkheads
- Thread starter jrich
- Start date
RFSchaller
Well Known Member
For what it's worth we used to use an equation called Archard's Equation for tube wear from supports in heat exchangers. Among other variables contact force was dominant. It would seem that slack steel cables (hard) resting on aluminum (Soft) with little relative motion would cause negligible wear to the bulkhead. That would be my take on it.
Since you are currently doing the condition inspection, did you find any evidence of rubbing damage when you inspected it for condition
.If not (and I doubt that you would), then there isn't any need for concern.
Changing the length of the rudder cable links wont have any effect on whether the cables hang onto the bulkheads when no ones feet are on the pedals. All it will do is change the neutral position of the pedals for or aft (depending on whether you lengthen or shorten the links).
I'm (trying) to reset my stab cable turnbuckles after retensioning and resetting the stab/stick stops and can't help but notice that the rudder cable lies smack-dab in there, jingling and jangling around with the tensioned stab cables. I'm an old guy from a planet far away, but nothing about this situation, or these rudder cables lying loose in the tail section, resonate with anything I've learned over 50 years+ playing around with aeroplanes.
Bob Bogash
N737G
Bob Bogash
N737G
I can understand where you are coming from Bob, but then it also shows that none of that 50 years was working with RV's, because they have all basically been that way since the first one was built 40 years ago.
Actually Scott, I think if you look back, you will find that return springs were used on the earlier RVs. My RV-6 plans, circa 1989, called for these springs on the rudder pedals.
The RV-3 and 4 go back even farther than the 6 and I don't believe they ever had any springs.
You and I both know (we both were early RV-6 builders) that the springs on the RV-6 were just to prevent the pedals from falling back flat on the floor... it had nothing to do with the need to keep the cables tight.
I totally agree with you, Scott, on the fact that the rudder cables don't need to be held tight. However, as one of the archeologists who recently went through the RV-3 plans....they do show springs - probably just to keep the pedals from flopping.
Thanks for keeping me honest...
Though I guess I sort of have a Masters Degree in RV, it is obvious I do not have a minor in RV ancient history
