Rudder cable bulkhead hole

beberle · #1 12-11-2012, 06:47 AM

I'm having a problem with rudder travel. Right rudder is fine, the clevis just hits the snap bushing in the left bulkhead. After much research, I'll be adding the split tubing to smooth that out.

However, Left rudder travel seems to be limited either by rudder cable length or because the right bulkhead hole is too low. The clevis body doesn't move far enough aft to hit the snap bushing because of cable tension.

Any thoughts?

robertahegy · #2 12-11-2012, 09:47 AM

Have you set your rudder stops yet? With the rudder stops set to recommended travel, this might be a non-issue. I know this is very close and I wondered about it when I built my 7A. Never had a problem once completed, though.

Roberta

beberle · #3 12-11-2012, 11:43 AM

I just purchased my 6-A two months ago. The rudder will come close or hit the right stop, but the left won't because of the cable bend at the 1st bulkhead. I'll have to measure the rudder deflection left and right to see where I'm at.

gasman · #4 12-11-2012, 02:21 PM

If your kit was purchased around mid April 1998, Van's shipped the wrong cables to a few customers. The correct cable number is F-6121.

Drawing #40 shows them to be 161" eye to eye.

AF_Alan · #5 12-12-2012, 09:31 AM

I recently connected the rudder cables on my 9A for the first time and found the same issue...good throw to the right but less than 1/2 deflection required on left pedal due to cable angle between pedal and co-pilot 1st bulkhead, exactly like your picture.

Appears my problem is that I positioned the pedals for comfort (tops leaning slightly forward) instead of vertical. My plan is to lengthen the rudder cable links (F-6119) about 1" to get the bottom edge of the pedals further forward from the 1st bulkhead. Haven't tried it yet. Downside is potential to ride the brakes on the ground or having to add an aftermarket extension on pedal bottoms.

Good luck!

alpinelakespilot2000 · #6 12-12-2012, 09:50 AM

Quote:

Originally Posted by AF_Alan

My plan is to lengthen the rudder cable links (F-6119) about 1" to get the bottom edge of the pedals further forward from the 1st bulkhead. Haven't tried it yet. Downside is potential to ride the brakes on the ground or having to add an aftermarket extension on pedal bottoms.

Alan,
Unfortunately, changing the length of the links will probably not address your issue, at least not fully. It's largely a function of how long the cables are. One thing that I found helped was to insert the bushing from aft side of the bulkhead. Though counterintuitive, it better guides the clevis toward the hole in the bulkhead. This topic has been addressed a number of times in the past, so if you search a bit in the archives you should find some more to mull over. Good luck.

jimbower · #7 12-12-2012, 10:21 AM

My rudder cable clevises were knocking the snap bushings out too...then I inserted them from the front and all was well.

Jim Bower
St. Louis, MO
RV-6A N143DJ
Flying

az_gila · #8 12-12-2012, 11:38 AM

This is a -6x correct?

There was a change in hole location on the vertical web (F-602) nearest the rudder pedals when Van changed from the floor mounted pedals to the overhead hanging ones.

The hole was changed to be 7 inches above top surface of the lower longeron.

Rev R6 on sheet 25

Do you have the lower old hole locations?

WenEng · #9 12-12-2012, 12:47 PM

What makes me think so is the higher angle from the Clevis to the snap bushing and the shortness of the link. Az_gila has a point to check out first. Setting pedals is such a personal thing. The previous owner may have had short legs, or wanted the pedal bottoms canted rearwards more for the neutral position. The further forward the rudder pedal bars are located and drilled through the longerons and the further towards vertical the pedals hang, the lower that angle is. For peace of mind, why don't you clamp the rudder in neutral and disconnect the two links and see what it looks like with the rudder pedals in a nearly vertical resting position (maybe canted aft just a little). You may end up making new links, each side being a different length.
See this link for just one example.....
http://www.rivetbangers.com/forums/v...asc&highlight=

airtractor8 · #10 12-13-2012, 06:57 AM

Quote:

Originally Posted by beberle

I'm having a problem with rudder travel. Right rudder is fine, the clevis just hits the snap bushing in the left bulkhead. After much research, I'll be adding the split tubing to smooth that out.

However, Left rudder travel seems to be limited either by rudder cable length or because the right bulkhead hole is too low. The clevis body doesn't move far enough aft to hit the snap bushing because of cable tension.

Any thoughts?

I had exactly the same problem with my 93' RV6. The rudder cables clevis would hit the snap bushing before reaching full travel. It was the same on both sides. The cable also did not have a straight pull just like your pic but probably not as bad.
To fix this I elongated the hole in the bulkhead so I got a straight pull for the cable and then made a "U" shaped stand off from .032 and riveted this to the rear side of the bulkhead. It had the hole in it for the snap bushing. Doing this placed the snap bushing further rearward and so I got both a straight pull for the cables and no fouling of the clevis end to the snap bushing.
I originally thought about adding the split tubing as you suggest but that did not solve the cable being deflected as shown in your pic. I am sure if left like that it will wear through the snap bushing and you will have cable wearing on bulkhead in no time.
A written description is always harder to understand than a picture so I will take some for you and post here tomorrow. It was an easy fix.