Saturday, July 4, 2015

Rigging Of The Rudder Pedal Cables Continues

Now that the rudder cables have been pulled through the tailcone it is time to begin rigging the rudder cables. In essence, what is about to transpire is the rudder pedals are going to be locked and the rudder cables will be temporally attached directly to the rudder pedals … then pulled taut by pulling aft on the F-1258 cable links temporarily attached to the aft end of the ruder cables. When the slack is pulled out of the cables, the links will be clamped in place on the rudder horn and the hole in the rudder horn will be used to mark the F-1258 cable links for drilling. After the holes are marked and the F-1258 links drilled, the links will be moved forward and permanently installed onto the rudder pedal horns. Smart people at Van’s … it is far far easier to take the slack out of the cable and mark the links for drilling at the tailcone end … as opposed to doing this while all scrunched up between the center tunnel ribs.

The rigging process begins by temporarily attaching two of the four F-1258 cable links (that have a center line drawn on them) onto the aft ends of the F-1239 rudder cables. The rudder cables are pulled forward and temporarily attached onto the horns on the rudder pedals. Maks sure to keep a string tied onto the rudder cable at all times to prevent it from dropping onto the tailcone.
F-1258 link with center line temporarily attached to the aft end a rudder cable.

The rudder cables were pulled forward and temporarily attached onto the rudder pedal horns. Blue masking tape was used to hold the bolt in position on the rudder pedal horns so I could screw the nut on one handed.

Next a rudder stop needs to be fabricated. The plans give instructions on how to make a the rudder stop using wood from one of the Van’s shipping crates. The rudder stop is used to lock the rudder pedals in a neutral position.  So I had to put aside the metal working tools and break out the jig saw to become “Samurai Woodsman” and cut up some wood from a shipping crate to fabricate the rudder stop. A 6" strip of plywood was removed from the lid of one of the shipping crates, then cut into two pieces 16 1/2" inches long. The remaining scrap of wood was cut to 5 1/2" to form the "H".
Cutting the 5 1/2" piece of wood that creates the center of the “H” … the two larger strips of plywood in the foreground have already been cut to length.

The two long pieces receive cutouts at both ends. One of the cutouts will slip over the rudder pedals and the cutout at the other end will sit on the F-1202F bulkhead. The 5 1/2" piece of wood is used as a center spacer to nail the two longer pieces onto … forming a “H”.
All three pieces ready to be nailed together to form the “H” shape of the rudder stop. Note duplicate cutouts were created on the two longer pieces of wood.
Results of playing “Samurai Woodsman” with the jig and band saws. I cheated a little as the center piece should be 6" high … did not want to cut another piece out of the plywood so the center is a little shorter than the plans call for … no big deal it is only used to keep the two larger pieces spaced parallel. The “H” looks like the plans (except for the short center piece of wood) … so time to put away the “Samurai Woodsman” tools, clean up the saw dust and put the rudder rigging stop to good use.

The rudder pedal rigging stop is installed on the pilot’s side … the forward portion of it sits on top of the left and right rudder pedals. The aft portion of the rudder pedal stop sits on top of the F-1202 bulkhead. This locks the rudder pedals in the neutral position so the slack can be pulled out of the cable and the drilling location marked onto the F-1258 cable links.
The fabricated rudder pedal rigging stop installed on the pilot’s side.

The plans instruct the builder to center the rudder then pull back on the F-1215 cable links to remove slack from the cable … while pulling back on the links a clamp is to be used to secure the links onto the rudder horn. I was doing this by myself and was making the rudder move either by pulling the slack or while clamping with one hand. After a few cycles of frustration, decided to just lock the rudder by using strips of wood clamped onto each rudder horn to prevent movement while the rudder cables were pulled aft and clamped onto the rudder horn. Measurements were taken from the center of the holes in the rudder horn to the tailcone’s aft bulkhead and equal position was achieved at around 2 3/8" (if memory serves me correct). The clamping worked out great!
Rudder locked in a neutral position by using two strips of wood clamped onto the rudder’s horns.
View of how both sides of the rudder was clamped in a centered position.
Closer view of the left side of the rudder horn clamped in a centered position.

By having the rudder locked, I was able to pull all the slack out of both rudder cables and clamp them onto the rudder horn by myself. Once clamped in position, the hole in the rudder horn is traced onto the F-1258 links. Of note, this process will create long and short F-1258 links. Not to worry … this is because the arms at the rudder pedals are offset … so this process is creating long and short F-1258 links to accommodate for that difference.
The F-1258 links for the left rudder cable will become the long links.
The F-1258 links for the right rudder cable will become the short links.

By this time it was getting late so did not finish drilling the links … so that will be the first task during the next work session.