CF rudder brake pedals

[jimboflying]

I made some custom Carbon fiber pedals for the rudder and brake operation on my 2+2 project. I added some silicone powder to the West System epoxy to add some wear resistance and to make the black color throughout the depth. The end result saved some weight and should be durable.

 

[DENNY]

It might just be the angle of the picture but it looks like you will always be applying brake with any rudder application?
DENNY

 

[PA14driver]

What master cylinders are you using? They appear to have an attach point for an emergency brake cable. Access to bleed?

 

[stewartb]

You angle looks very vertical, but photos are deceiving. Clever idea. Is the raised toe adequate to keep from accidentally applying toe pressure below the raised part when depressing rudder? I converted my toe pedal arm from straight to arched to prevent unintended brake application from toes on the support. It was worth doing, too.

 

[jimboflying]

In answer to questions. 1: At the bottom of the CF plate is a hinge point that allows for rudder pedal movement without brake application.
2: Each cylinder has its own reservoir and fill port and the tab for locking the brake.
3. The final angle of the assembly has not been finalized yet as it is influenced by the rudder cable length and the vertical shaft adjustment on the brake cylinder.

 

[stewartb]

Whose masters? I'm not familiar with the external spring.

Fitting the brake pedal angle is a process. I've re-set mine several times.

 

[DENNY]

So are you going to have to lift you foot off the rudder pedal and move it up on top of the bump to apply brakes?
DENNY

 

[hotrod180]

It might just be the angle of the picture but it looks like you will always be applying brake with any rudder application?
DENNY

x2.
Depends on how your feet ride on the pedals,
but I'd think maybe the bump should be on the bottom.
I needed to add to the bottom of the pedals on my 180 to prevent uncommanded brake application.

 

[Mr. Ed]

My Maule has those master cylinders with the external spring. The springs only purpose is to depress that brake tab to the off position.

 

[skywagon8a]

My Maule has those master cylinders with the external spring. The springs only purpose is to depress that brake tab to the off position.

It also ensures the parking brake will not be applied by mistake. The end of that lever is pulled up and held by a cable while the pedal is depressed. When the pedal is released the lever grabs the brake pushrod holding it down. The spring is a safety feature which early versions of this type of master cylinder did not have.

I had one of the springless parking brake levers grab the push rod in a Cessna 170. Fortunately the landing was on snow, so some quick foot work saved the day.

 

[stewartb]

Groves don't have an external spring on the park brake arm. Maybe there's one internal? They work great.

 

[jimboflying]

This is the current pedal positions with temporary rudder cables. The brake reservoirs are Gerdes.

 

[stewartb]

Nice. That should work well. It looks like you have a long way to go but I look forward to a pirep.

 

[jimboflying]

I plan on flying it on Thursday. I just don’t know which Thursday.

 

[mam90]

The second Thursday of next week?

 

[jimboflying]

Should be ready by then!

 

[Crash Jr.]

How are you making it work so that the cylinders are pressed slightly when you're pressing the rudder pedal? Seems like just visually you run the risk of braking one side if you press the rudder pedal down hard.

 

[jimboflying]

Photos #2,3 of the original post show a hinge point at the bottom of the CF part so the rudder pedal post sticking up can rotate without depressing the brake. The brake cylinder also has a pivot point at the bottom where it attaches to the floor. You keep your heels on the floor and your toes away from the top where the bump is. It is like other toe brake systems with just a different top part made out of CF to save the weight of the metal casting.

 

[jimboflying]

Since it is Thursday I thought I would show the progress on the Pedals. They are working as expected.