Rudder system rigging

Basically what the title says. Tonight I got the rudder pedals rigged up.

Last time, I quit for the night after realizing I needed the rear pedal hardware in place before messing around with the pedals. Here’s a look at what the attach between the aft rudder cables and the short ones attached to the pedals looks like. I put the bolts in here last time just so they’d have somewhere to live:

So I went poking around trying to figure out where I put the rear rudder pedal kit. That’s building in a nutshell, you can spend an amazing amount of time wandering around the shop looking confused. Anyway, once I got the kit and the proper hardware, I got the idler arms installed, and then the cables reattached. Basically, the only difference here is that the connection between the two cables also is in common with the top of an idler arm. The rear pedals are a couple plunger-type pieces that push on the tops of these idler arms.

Here’s the new/correct rigging up here:

With that done, the final step was to attach the forward ends of the cables to their anchor points on the firewall. The basic way the rudder cables function is that the cables pass through S-shaped passages on each pedal. When a pedal pivots, it “wraps” the cable with that S-shaped passage, thus pulling on that cable (or relaxing, depending on direction of movement. At the same time, if the pedals don’t pivot, they can slide forward or back (for adjustment) without pulling the cables. Kind of ingenious, really.

Anyway, at this point the resting position of the pedals are adjusted by moving around washers on the forward cable anchors. The shanks of these pieces are way longer than the holes they go through, and by changing the distribution fo washers between the forward and aft sides of the firewall, the resting position of a pedal can be changed. So the procedure is to clamp the rudder in a neutral position, and mess with the washers until the pedals are vertical. I ended up setting them up with a slight rearward angle, as otherwise they get really close to the firewall at full deflection. I can always tweak this down the road, of course.

With that done, I had a functional rudder system. Which I of course tested by climbing in and actuating the pedals. Which was cool, but I also noticed a sort of chafing noise, which concerned me. I got Josie to come out and look around while I work the pedals, but there seemed to be no single source of the chafing. Some research on VAF seems to indicate that it’s not unusual for the cables to make contact with the snap bushings that line bulkhead passthroughs, but I’m still unsure about the sound. Time to go make a post and ask.

The other thing I noticed while sitting i the cockpit is that the rudder pedal assembly isn’t as secure as I’d like. The forward-aft slide bar is bolted securely in place, but the nylon blocks at the left and right sides, which I thought were supposed to rest on the floor, don’t. Thus the pedal assembly can rock left and right a bit around the slide bar. There’s another thing to ask about…maybe I’ll need to add some spacers down there. On the other hand, if it fits tight against the floor, seems like that would make adjusting the pedals challenging, so I’m kind of unsure here.

But hey…rudders!

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