Monthly Archives: June 2020

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Rudder Pedals and Brake System (2)

Due to an interference between the original brake lines and the forward tunnel cover, I decided to a redo would be appropriate.

For this attempt at bending, a jig based on the exact firewall geometry was first emulated with coat hangers, then laid out on the workbench.  The wooden constraints matched the indented box and helped make the two 45degrees bends in quick succession align properly.

 

 

The remaining bends were rough bent with the Imperial tube bending tool. The final configurations were carefully adjusted by hand.  Since these were with the ‘hard’ aluminum, the risk of cracking or compressing during the manual operation was minimized.  I am much happier with the final outcome.

 

Here the forward tunnel cover was relieved about 1/2″ from the stock cutout.  Even the new, better fitting brake lines would not fit into the original space.  On the right, the pilot side flexible lines were cable laced together on the workbench.

 

 

Here the rudder pedal / brake assembly is fit into the bearing blocks and bolted to the mount plates.  The flexible lines were hand tightened to check for lines rubbing together. Pinch points will be covered with plastic spiral wrap, then final cable lacing where needed.

 

 

The left photo shows building a cardboard template for cutting ceramic mat insulation for the forward tunnel.  RV10s generate plenty of heat transfer from this location as the engine exhaust pipes are immediately on the opposite side of the firewall.  The right photo shows relieving the stock Vans fuel valve bracket to accommodate the Andair valve and TS Flightlines flexible fuel hoses.  More on both these items later.

 

Rudder Pedals and Brake System (1)

The continuation from the brake line fabrication is preparation of the rudder pedal system.

The bearing blocks and mount plate were laid out with the corresponding hardware ready for processing.  The blocks appear to be black Delrin (or equivalent).

 

 

 

 

The center bearing block was measured, then drilled with a #10 drill to accept AN3-22A bolts.  The block was then cut in half for later mounting to the rudder pedal brace.

 

 

 

The side bearing blocks were drilled about 1/8″ deep using the mount plates as a template.  The remainder of the hole was completed in the drill press to achieve perpendicular alignment.

 

 

 

A feature recommended by other builders for the side bearing were oil holes added to the bearing blocks. These facilitate lubricating the friction points after installation.  The depth and location are first checked before going to the drill press.

 

 

 

This photo shows the completed bearing blocks after addition of the oil holes. Deburring the Delrin on the inside of the bearing hole required the use of a Dremel tool.

 

 

 

 

Spacers for the lower brake cylinder attachment point were made from AT6-058×5/16 tube. These are sized to accommodate AN3-12 bolts.

 

 

 

 

The main pedal parts were staged for match drilling and preparation for priming (SEM Self-Etch Primer) and final paint (PPG Concept – Boeing Grey).

 

 

 

Parts staged, primed and painted.

 

 

 

 

The brake doubler plates and brake pedal side plates were riveted together to make the brake pedal subassemblies.

 

 

 

 

All the prepared parts and hardware were stage for attachment to the pedal levers.

 

 

 

 

The Vans kit uses Matco brake components.  Here the completed pedals are enhanced with AeroSport pedal extensions 3D imprinted with N190XB.  Next actions are to fit these units into the fuselage, then attach soft brake lines.

Brake Lines (2)

After bending the under seat lines, the next step was install RattleTrap xTreme sound dampening material and continue with line fabrication.

Because of the adhesive backing on the foil sound dampening (potential fire hazard), that material will only be installed under the seats and rear portion of the tunnel.  Eventually the forward tunnel and engine-side firewall will be covered with Fiberfrax ceramic mat and stainless steel foil.

 

 

Here are pictures of the brake lines installed under the left seat and tunnel.  The material used was 1/4″ diameter ‘hard’ aluminum tubing. Flexible and stainless covered Bonaco lines will be used for the pedal connections, but the idea here was permanently install the fixed lines in static locations. Hopefully they should never need to be removed.

 

 

The bends on the right line were made more complicated than needed, but this line did fit well.  The lesson learned was applied to the left side, where the construction was simplified during the bending process.

 

 

 

The left photo show the AirWard parking brake kit which includes a Matco hydraulic valve.  That right photo is the forward tunnel after the heater plenum was installed with #6 screws.  If in the future the brake lines ever do need replacing, having a removable plenum will make the job much easier.