February 17th, 2013

Got a bit behind on the log so it's catchup time.

 This week I finished up the brace structure for the forward wing tank mount/main gear.

Next thing was to get started on the rudder pedal assembly.  The reason we do this now is because it is *so* much easier than trying to do it with the floor in place and having to lay upside down and work on it.

 I started out planning to only have brakes on the pilot side, just like we have in our Cherokee (and your car of course - funny how we're nervous about only one set of brakes in a plane when nearly every car only has one set...).

 Now I look at it I'm rethinking, but I have plenty of time to decide to add them later, so for now I'm just going to proceed with the one set of brakes.

 The rudder pedals/brakes consist of two welded tube structures, one behind the other; both left pedals are on the aftmost tube, the right pedals are on the forward tube. The tubes ride in bearing blocks supported by the F719 stiffeners and an additional center brace attached to the center of the firewall.

From Fuselage Kit

The brakes are a couple of pedals (or 4 if you opt for brakes on both sides) attached directly to small master cylinders attached to the rudder tubes.

 First thing to do is assemble the brake pedals. The pedal consists of a thick plate with lightening holes, with angles on the back (forward) side to provide a pivot point and provide a place to mount the plate that will actuate the brake cylinder.

 The RV has differential brakes, i.e. you can brake each wheel individually and independently.

 Here is the left pedal assembly after cutting some angle to length, fitting and deburring everything. I actually have the actuator plate backwards in the picture - it should be on the right. Realized it and moved it prior to drilling/riveting.

From Fuselage

I decided to leave the pedals bare metal for now. I may decide to paint them later. Once I match drilled the angle to the pedal I riveted it with some 1/8" AN426 (flush) rivets.

From Fuselage

After that, the actuator plate gets riveted to the correct side (left pedal on the right, right pedal on the left). 

The master cylinders are mounted vertically between the pedals. They will be match drilled to the pedals later when final fitting everything. I don't want to do that now because I want to sit in it and see how your feet naturally fit to the pedals so I can make sure the angles are correct (don't want to make it too easy to ride the brakes by accident).

 Once the brake pedals are done, the bearing blocks are drilled for the attach bolts. The bearing blocks are made of UHMW plastic, and although they are drilled to fit the tubes, you have to drill the bolt holes yourself, which entails making a very straight 3/16" hole vertically through about 1 1/2" of plastic that is about 3/4" wide.

After some experimentation, the best solution I could find was to clamp all three bearing blocks together to make keeping them plumb easier, then drill them all at once on the drill press.

From Fuselage

Because the throw on the drill press is not very far, and the plastic is fairly thick, and I start at #40, then do #30, #19, then finally #12, it takes a while.  Oh - forgot to mention the plastic heats up when drilling so it tends to bind a bit.  Suffice it to say I spent almost 2 hours drilling 6 holes between all the bit changes and moving the table up and down.

The black piece is the center section support - it gets cut in half after drilling so it can be mounted to the center support brace.  The blocks are taped because you can't write on the plastic very well.  I just used painters tape and peeled it off when I was done.

Once the bearing blocks are drilled, they are fitted to the rudder tubes and match drilled to the F719 stiffeners.  With the fuselage upside down a lot of time is spent head scratching, staring at the plans, test fitting, double checking, etc.

Here's what it looks like after the tubes are in place and I've started match drilling the bearing blocks to the longeron.  In this shot I only have the left brake pedal in, and the master cylinders are just free floating.  They will get brakes lines and such much later in the process.

From Fuselage

After drilling the outboard blocks, the center support brace is fabbed and drilled to one of the angles on the firewall.

From Fuselage

This is a shot of the entire assembly finished as far it is going to be for now.

Bearing blocks all match drilled and bolted, pedals complete (for now) and mounted.

 There is some provision for moving the entire assembly to accommodate different leg positions by drilling additional holes in the support structure. Right now it is set up for the forward most position (and most leg room). I will later drill some additional holes to allow moving it if I want, but will not be able to determine final location until the fuse is flipped upright and I can sit in it.

From Fuselage

February 10th, 2013

This week I worked on the spacers and support brackets for the fuel tank attach brackets. I don't know what it was about these things, but I had to make more of these than any other part so far.

 Ended up going through 5 parts to get 2 good ones.  I would make a part I was really happy with, then either drill it incorrectly, or make a cut in the wrong spot and have to start over.  Thankfully Vans gave me miles of .125 3/4 x 3/4, so I would just start another one and carry on.

 There's not a lot to see on this. There is a bracket on the inside, a spacer between the F9101 gear attach web and the skin, and then finally on the outside there will be an attach bracket that will bolt to the bracket on the fuel tank. The inboard structure is to beef up the area to provide enough support for the tank attach bracket.

Started off making a couple (left and right) of F996B spacers.  The plans are pretty vague on where this goes, so at first I used the spacer itself inside the two longerons to see about where it would fit.

From Fuselage

Next I fabricated a right handed F996C bracket. The bracket is made from .125 x 3/4 x 3/4 angle, there are various holes and cuts you have to make so it will fit between the longerons and line up with everything.

From Fuselage

Here's the part when it is more or less finished.

From Fuselage

Once I had the angle fabricated I realized my initial guess on the location was too far aft. Eventually I ended up measuring the drawings and scaling up the measurement and determined there was a rivet hole that matched the location shown on the plans, so I put it there.

Once all the parts are correct you match drill the angle, spacer and F9101 web to the longerons.

From Fuselage

Finally, a couple of "keeper" rivets hold it together.  

From Fuselage

Eventually the 4 remaining holes will be enlarged to 3/16" for some AN3 bolts that will bolt the attach angle to the brackets and the brackets to the web and longerons.  That happens later when getting ready to mount the wings.