Carlson Skunk Works

I keep putzing along and making progress. I am amazed that there are getting to be fewer and fewer “projects” to complete each day! I am starting to feel like one of these days the plane will be done.

So one of the unfinished items from last post was the seat and baggage area. Other than upholstery the seat and baggage area are now complete.

The back of the baggage area is a wooden frame with a 1mm plywood front. I added a couple of small wood blocks behind it on the window framing to keep it from falling backward into the fuselage. The whole assembly is easily removed to allow access to the elevator bellcrank and aileron cable ends.

Another item was the air intake which got crunched when the plane took a nose dive. This has been cleaned up, straightened and reinstalled.

I still need to safety wire two bolts and castle nuts toward the front of the assembly.

Before I can glue the plywood over the nose and dash I want to get the wiring and plumbing installed. The first order of business was to figure out how to activate the starter motor. The C-85 has a “pull starter” that requires a cable or rod to be run from an arm on the starter to the cockpit. Here is how I finally decided to do this:

I used a 3/16″ rod for my actuator and bent it at a right angle, then threaded the short end.

I eyeballed the anticipated run for the rod and drilled a hole in the firewall. The hole is large enough for a steel tube to extend through the firewall and act as a guide for the rod. Another hole was drilled in the instrument panel where I wanted the end of the rod to be accessible for starting the engine.

Of course, the rod had to go over the fuel tank and miss the filler neck, but everything just seemed to work out.

The next thing was how to actually pull the rod from inside the cabin. I had some left over pieces of Delrin, so I drilled a 1″ hole for my finger to go through and a hole for the rod to go through. I used the Dremel tool to shape the edges and make a notch to accommodate a nut and washer.

Next on the list was to decide how to control the throttle. Yesterday I spotted a throttle and mixture control quadrant on Barnstormers, so I contacted the seller and it should be shipped later today. I have quite a bit of Belden cable left from the trim control, so I started working on running some of that.

This looks like it will work out quite nicely! The next issue is how to mount the throttle quadrant assembly? So I added a piece of wood reinforcement between the fuel tank restraint and the instrument panel. I won’t be able to complete the installation until I have the throttle quadrant, but this is a good start.

As long as I have good access to things, I decided to complete the fuel gauge sender installation. I had the base of the sender in place on the fuel tank just to keep dirt out, but I needed to install the float. Following the instructions that came with the unit was pretty easy. The hard part was getting the assembled unit into the fuel tank. I ended up loosening the sender rheostat so it could slide down the support and fit through the hole. Then I could slide it back into place and tighten the screws to secure it. The other surprise was that the float now sits toward the side of the tank rather than toward the center of it. If you use one of these, be sure to take into account which way the float will extend from the support before you weld the mounting ring to your tank. The holes in the mounting ring do not allow for multiple positions of the sender!

So the wings are done, that means that I need to finish the fuselage. There are quite a few details that need to be dealt with before I can start covering and painting.

One requirement is that the plane be fitted with an ELT. I purchased a used Pointer ELT at the AirVenture Fly Mart a couple of years ago. However, I thought I would just buy a new Ameri-King AK451 from Aircraft Spruce instead. I ordered the new unit, but was informed that these are no longer available from AS. At that point I decided to use the ELT that I already had. Parts are available for it from AS, so I can still get a new battery and it is still legal.

My ELT needed an antenna, mounting tray, and new battery at a minimum. I also wanted a remote switch. When I added up the cost of these on AS it became obvious that a bit of time looking for used parts might save a considerable amount of money. I was able to get the antenna, mounting tray and antenna cable on Barnstormers. I still will need a remote switch and a new battery. The switch kit is available at a reasonable price from AS and will be part of my next order. I will order a new battery just before the final inspection. That will get me the longest time before it needs to be replaced again.

I bent up a mount for the antenna and bolted it in place. Then I attached the antenna cable and zip tied it in place.

Another thing that needed to be done was to improve the tail spring mount. There is a large bolt holding the front of the leaf spring in place and I had a couple of threaded rods farther back to hold the leafs straight. The threaded rods needed to be replaced. I decided to make a “U” type of bolt with nearly square corners at the “U” end. So I got a piece of 3/16″ steel rod, bent it to shape, cut it to length, and threaded the ends of the legs.

That worked pretty well and I was having some issues with finding bolts to hold the horizontal stabilizer to the fuselage, so I got a piece of 1/4″ steel rod and repeated the process.

I will probably need to cut the threaded ends off a bit, but that can wait for a while.

The elevator cables rubbed against each other near the middle of their runs. I tried to come up with some type of small separator, but couldn’t get things to work quite right. What I finally came up with was a chunk of PVC pipe that would sit between the cables and have guide notches cut in it.

The plans call for the fuel tank to be mounted in the nose of the plane aft of the firewall. I followed the plans to build the fuel tank, but found that the specified mounting method just didn’t work for me. So I came up with this mount:

That holds the tank up and across the top I added a wooden restraint to hold it upright and generally in place.

The curve of the top of the fuel tank is not the same as the curve of the top of the firewall. That put the fuel filler neck and cap inside the nose of the plane. I took the filler neck to a friend who cut it and added a piece of tubing to extend it to reach above the nose deck.

That worked out quite nicely. HOWEVER … while working to get the fuel tank in place I managed to push on the nose of the plane just a bit too much and it v.e.r.y..s.l.o.w.l.y tipped over onto it’s nose! Fortunately the engine was not running and the “tip over” was very slow, so damage was minimal.

Only the air intake box was bent and I think I can straighten it. It will need to be removed from the carburetor, though.

So, with that experience behind me, I tied the tail of the plane to the workbench.

The next project was to design and build the seat and luggage area. I decided to have a bench seat with a back rest that would tip forward for access to the baggage area.

Under the seat will be storage area for an emergency kit, some tools, and misc items that do not need to be accessed during flight.

The luggage area is behind the seat and has enough room for a couple of suitcases, a small tent, and a couple of sleeping bags. I still have to build the retaining wall/device so my luggage doesn’t end up in the tail.

The seat and luggage area are easily removed, should that become necessary, by taking out a couple of AN-3 bolts.

In my “spare” time I have been helping my son insulate and sheetrock his garage. He suggested that we move the fuselage into the long bay in his garage this winter, so we can finish it up and have everything ready to fly in the spring.

Now, on to the rudder pedals, brakes, and instruments!