Rudder pedal installation

It was now time to install the rudder pedal assemblies. Since these are not the plans version of the pedal design, I had to come up with my own method of installing them. I followed the same method I used for installing the speed brake actuator to the back of the pilot's seat. The idea being to glass a strip of 1/4" plywood with tee nuts onto the floor pans and bolt the rudder pedal u-channel onto it.

So here are the rudder pedal assemblies...



I started out by cutting two trips of 1/4" plywood (1.5" wide and 16" long). Recall that the u-channel is 14" long - I added an extra 2" so that the pilot will be able to adjust the pedals forward or aft during preflight - more on that later.

Before cutting the strips, I used my router to apply a 45 degree lip on the inboard and forward edges - hence the 1.5" width (recall that the u-channel is 1.25" wide - the additional 0.25" allows for the 45 degree transition ramp between glass and plywood). 


I then used the drill press to make three holes - using a drill bit size that allowed the tee nut to be inserted into it.


I then lined up the wood strip with the u-channel and marked the holes onto the u-channel.


I then moved the u-channel back an inch and marked the holes... and then back another inch and marked those holes - thus creating three stations which the pilot has the option of adjusting the pedals to.

To drill the holes, I clamped the wood strip onto the u-channel and match drilled them. IMPORTANT NOTE: I only used the original drill bit used to drill through the wood to mark the u-channel; I then used a smaller drill bit to drill through the u-channel (the size of the bolt diameter, not the size of the tee nut shaft).


When installing tee-nuts, it is difficult to put them exactly where you want them. To avoid any error, I passed bolts through the u-channel, installed the wood strip onto the u-channel, and then started to hand tighten the tee nuts on...


This assured me that the tee nuts would be installed exactly where they need to be.


I tightened them enough so that I could remove the bolts and have enough grip to remain in position. I then hammered them in - making sure they were as flush to the surface as possible.


Now that the strips were complete, I prepped the surfaces for bonding... here I am sanding away...


To keep the resin from getting into the tee nuts, I passed cling wrap through the threads...


And used a knife to trim them flush.


I then cut 6 plies of BID at 45 degree bias (3 plies for each strip) and got ready to prepreg.


Prepregging the first strip...


I then painted the top surface with plain epoxy and applied flox to the underside...


I then painted plain epoxy onto the interior of the nose and positioned the strip in place. I then applied a bead of flox all around. Notice how the 45 degree edge faces inboard and the gap between the nose panel wall and strip gets filled in with flox.



I then brought the prepreg over and positioned it in place.. using a brush to tuck all the corners and get all the air bubbles out.. also making sure to have at least 1" overlap onto the wall, floor and edges.


Then the left strip...




I then peel plied all the edges for a nice smooth transition...



After cure, I had to trim the overhang...


I used the multi tool for a rough trim...


And then hand filed for a smooth finish...



I now had to open up the holes and expose the tee nut threads.


I started out by making a small hole in the center using a very small drill bit...


I then opened up the hole with a countersink bit at very slow speed to make sure I wouldn't damage the tee nut thread below.


With the tee nut exposed, I now had to remove the cling wrap inside the thread. At first, I tried using a very small screw driver, an exacto blade, tweezers... and nothing worked. After getting fed up, I used a drill bit slightly smaller than the tee nut thread and the cling wrap came right out. I was scarred to damage the threads, so I made sure to drill extremely slow.


Taaaa-daaaaa! Tee nut thread exposed and zero epoxy in the the threads...


Test fitting the bolt...


With all tee nuts exposed... it was time to bolt the assembly onto the floor. Notice how I have 3 options on where to place the assembly. I consider myself a tall pilot (6' 1") so I am mounting the assembly at the farthest forward position.


I used AN3-3A bolts with AN960-10L washers.


So if a shorter pilot wants to fly the airplane, he or she can simply remove these bolts and place the assembly 1" or 2" aft of the current position.


I then reconnected the pedal pushrods and completed the rudder pedal assembly installation!


10 comments:

Co. said...

I usually fill nuts with wax melted from a candle using a heated spoon, it had worked pretty well for me .

Capt Meatballs said...

I like the tee-nuts idea, I think I will steal it! :-)

Matthew Elder said...

I typically use plain old painters masking tape to cover the back side of t-nuts... This keep the crap out, and the bolt goes right through it. Keep the size down to just about cover the hole only.

Ray's blog said...

How do you actuate the rudders to the stops before brake actuation. I probably just don't understand the full system you are employing.
I hope to get down to see your ptoject soon!

Ary Glantz said...

Each pedal has a metal tab facing aft at the top of the pedal corner. A clevis will get attached to this tab, which will be attached to the cable that runs all the way to the aft end of the fuselage, through the firewall, pulleys will redirect them through the wings and finally to the rudders on the winglets. Let me know when you want a tour of the garage!!

Ray's blog said...

But it appears that the brake master cylinder will be depressed as soon as you begin pressing on the pedal. The rudder should be fully deflected before the brake is activated.

Ary Glantz said...

Not so. The pedal has half travel prior to hitting the large washer... so the pedal first deploys the rudder (prior to any braking), then begins to brake after the rudder has hit the full limit stop. It will be more clear after I make the cable connections in later chapters.

Brian Ashton said...

Hi Ary, Do you have a materials list for the hardware that connects the rudder pedal to the Matco MC4 master cylinder? Thanks, Brian

Ary Glantz said...

Brian, see if this is what you are looking for: http://www.aryjglantz.com/2014/05/rudder-pedal-assemblies.html?m=1 Otherwise, let me know and I'll try to clear it up.

Brian Ashton said...

That's exactly what I was looking for... thanks! Brian