S

Steve Sampson

Well Known Member
Having checked out the controls, I find the rudder cables are interferring with the rudder stops. (It never occured to me to rig the cables before it was painted.) The cables can ride under the stop and come close to locking up. Am I the first to manage this and what is the normal fix. Can I put a slight bend in the SS end fitting perhaps?

There is a sequence of pictures here, http://gikonemp.blogspot.com/2008/03/so-what-have-i-done-wrong-here.html#linksand I would really appreciate the '-4 team's' thoughts.

I have checked back against the plans and I cant see what I did wrong. I would have thought this would be a common problem, hopefully with a common fix, but I have never heard anyone mention it before and cant find it with asearch.

Thanks.
 
Steve Sampson said:
Having checked out the controls, I find the rudder cables are interferring with the rudder stops...
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Well I'm not a four guy but I had the same problem while building my six. I have seen lots of flying RVs with the problem too, but it is often set up so the cable could only jam when there is no tension.

To fix mine I just made a slightly different stop that cleared the cable.
 
Steve Sampson said:
Having checked out the controls, I find the rudder cables are interferring with the rudder stops. (It never occured to me to rig the cables before it was painted.) The cables can ride under the stop and come close to locking up. Am I the first to manage this and what is the normal fix. Can I put a slight bend in the SS end fitting perhaps?

There is a sequence of pictures here, http://gikonemp.blogspot.com/2008/03/so-what-have-i-done-wrong-here.html#linksand I would really appreciate the '-4 team's' thoughts.

I have checked back against the plans and I cant see what I did wrong. I would have thought this would be a common problem, hopefully with a common fix, but I have never heard anyone mention it before and cant find it with asearch.

Thanks.
Click to expand...

I did the same on my -6 but caught it as I was installing and adjusting the rudder pedals. I initially and logically, or so it seemed, aligned the horn of the stop with the horn of the rudder so that they would make the most rigid contact. However the cable centers on the rudder horn and therefore also aligns with the stop horn allowing it to interfere and rub on the slack side. I ended up raising the stop by about 1/4" to clear the cable and still make contact with the rudder horn.

Obviously a common problem.

Jim Sharkey
RV6 - Wiring etc
 
I've seen these small 'eyebolt' type screws used on quite a few -4's. The 1st pic is ours (we bought our -4), but I don't have a part number. I used these on my Champ, if no one posts the part number, I can on Monday when I get to work.

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I drilled mine out and swapped sides, so they are upside down now

that gave plenty clearance

sure seems a common problem!
 
Low n Slow said:
I've seen these small 'eyebolt' type screws used on quite a few -4's. The 1st pic is ours (we bought our -4), but I don't have a part number. I used these on my Champ, if no one posts the part number, I can on Monday when I get to work.
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Hmmmm........don't know about the eyebolt. The eyebolt has eliminated the safety margin of the clevis on the end of the rudder cable (double shear) because it is mounted in single shear. Seems like a lot of potential load on that little eyebolt. The eyebolt probably has about half the load strength the rudder cable attachment would have if attached per plans.

Don't think I would do this on my plane.
 
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Sam Buchanan said:
?The eyebolt probably has about half the load strength the rudder cable attachment would have if attached per plans.
Don't think I would do this on my plane.
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I?m sure you?re correct that it may not provide the maximum strength and it requires a very tight fitting hole, but I?ve seen more of these on certified taildraggers than I can remember.

Soon after I bought the plane I had a rudder failure during which I applied as much force as my adrenaline pumped leg could provide (see dent on corner) and it?s still as tight in the hole as the left side.
http://www.vansairforce.com/community/showthread.php?t=21073
 
I also had this problem on my-4
I trimmed down the stops so they were shallow giving minimal projection from the skin then fitted stop bolts to the rudder bracket. the bolts were adjusted by fitting a machined spacer under the head. has worked Ok for he last7 years.
 
Hi Steve!
You did nothing wrong, the same happenend to me. I called Vans, and they said someting like:" You're the first guy to ask, but you are right, it will interfere...." I just re-designed the stops, turnded them upside-down, bent them a little, cut them down as much as possible and now they are perfectly out of the way of the rudder cables. Your fuse is painted already, do you have the stops on it? This would mean destroying your nice paintjob....Another guy here just bolted a block of alloy onto (under) the rudder foot to get the cables more downwards, because he does'nt want to destroy his paint. It works well. I also riveted a thin piece of urethan to the contacting face of my rudder foot, now it stops the rudder more like a "pop" than a BANG :) Good luck!
 
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Thanks for all the messages/ideas/support.

Dirk, yes the stops are on and that is why I am going slowly before I fix because nearly all solutions mess up the paint. You can see it here Dirk.http://gikonemp.blogspot.com/2008/03/so-what-have-i-done-wrong-here.html#linksI have asked VANS if I can bend the stainless fittings on the ends of the cables. I think a small bend would be a solution.

What a shame VANS dont keep a public list of 'gotchas'!

I also like the idea of dropping the atach point though I am not yet sure how to do it.

Thanks everyone.
 
"What a shame VANS doesn't keep a public list of 'gotchas'!"

Perhaps we could get a 'skickie' in here for everyone to post their tips/fixes/gotcha's in...

I know there's a search function, but trust me, the output is a _lot_ to wade thru...

Dave
 
If you use the delrin rudder stop in your tail, is there any reason at all to install these metal, external stops?

The only reason I can think of is to use for a rudder lock, as identified in other posts on this site. In this case, the stop could be constructed in any manner, as it really doesn't need to match up with the rudder yoke to function as a stop.

For those who have not reached this point in the construction process, it would be one possible solution to heading off a future problem.
 
dsb said:
"What a shame VANS doesn't keep a public list of 'gotchas'!"

Perhaps we could get a 'skickie' in here for everyone to post their tips/fixes/gotcha's in...

I know there's a search function, but trust me, the output is a _lot_ to wade thru...

Dave
Click to expand...
I built mine per the vertical dimensions indicated in the plans and have no interference. That said, I had to build about three sets because Van's (horizontal) dimensions were too small to limit the rudder travel appropriately.
 
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