Match Drilled Bottom of Center Fuselage

I finished match drilling the bottom of the center fuselage. I was able to flip it upside down onto my EAA standard workbench. It fit perfectly. The more I know about building, the less inclined I am to "reinvent the wheel". Two feet by five feet is the standard EAA 1000 workbench. Several times I've had the workbench be the exact size I've needed and I don't think it's a coincidence. My recommendation to builders just getting started is to do what 10's of thousands before you have done unless there's overwhelming evidence to change. They usually did it for a reason. I'm trying to keep as much of the experimental out of experimental aviation as I can.

Working on Center Fuselage

Ready to match drill the center fusleage. Getting to be a rather large structure now. I may have to build another sawhorse to be able to flip the section to work on the bottom. Either that or lie on my back with the work above me.

The center fuselage is where the seats, control sticks and baggage compartment are and where the wings will attach to the side.

Finished Aft Lower Fuselage

I've finished the aft lower fuselage. I'm happy with the quality of the work. I was kind of playing to see if I could make show quality rivets. The key is definitely getting a good dimple. I had a few that were under dimpled and you can see a slight pucker around them.

 

Now it's on to the center fuselage section with the seats ribs. Lots of different tasks.

Redneck Ice Chest Air Conditioning

Here's the rough prototype of the Redneck air conditioning Austin and I made. We only spent about $60 because we already had the cooler and bilge pump. If you're starting from scratch, expect to spend about $100. Sporty's Pilot Shop sells fancy but functionally the same units starting around $500 and up! My daughter is using it now in her car as her a/c is kaput. It's meant to go in a small airplane. It is possible to install an automotive freon type system in a small airplane but they start at about $5000 for a portable system and go way up if it's permanently installed. You can buy a lot of ice or freeze a bunch of gallon milk jugs of water for that money.

We looked at several different designs but chose this one for several reasons. With the blower on the outside, it creates suction that helps keep the ice chest cooler lid closed. Also, with the screw-in plugs, the ice will last a lot longer when you're not using it as you can seal the two big holes (vent and blower).

We also liked the design of blowing air over the chilled heater core instead of just blowing it over ice. That keeps the humidity lower as it's doing basically the same thing as a freon system.

Hopefully, the pictures and video will answer most of the questions but here are some things that might not be clear. We didn't get a good picture of the plenum but all we did was take some scrap aluminium and mark a square the size of the heater core and added 1 1/2" to form a lip that we folded up and riveted to form an open top box. I used the skin from a rejected trim tab. Everyone that's building an RV knows what that is and probably has one. Some weather stripping would help seal it. The strap goes across the bottom to hold the heater core in. The plenum makes it cooler and more efficient by making all the air go past our heat exchanger (heater core) plus it makes room for the elbow of the blower to come down through the hole in the lid. It also eliminates a lot of sealing to the bottom of the lid that's required without it. We don't show it but another female clean out (or knockout) goes on the end of the blower so you can put a plug in it. Also, the wood block above the plenum shouldn't be there. That's to fill the hole in the bottom of the lid from one of our earlier attempts. On our next one, the plenum will screw right to the bottom of the lid.

The bilge pump and blower were both bought at Academy Sports and made by Attwood. Walmart probably has them, too. Get the smallest as they put out plenty of volume. The white 3" plastic pipes, clear tubing and electrical box were bought at McCoys but Lowes or Home Depot will have them, too. Get the size tubing that fits your heater core and bilge pump.

We got about 5' for the return line as it can be used for draining the water. We didn't need any extra electrical line as the pump and blower came with plenty. The two switches and a 12 volt "cigarette lighter plug" came from Radio Shack. The heater core is from an automotive parts store. I had to keep asking for the cheapest they had. It's hard to buy something from the chain stores without telling them what vehicle it's for. I think this is from an 80's Ford truck but didn't care as it was the right size and only $19.95.

We haven't finished all the sealing and such as this was just a prototype. It cools unexpectedly well and you can hear how well it seals in the video when the vent plug is removed.

Finishing Aft Fuselage

Almost finished riveting the lower section of the aft fuselage. The upper skins get put on later. I was trying to show the quality of the rivets in this picture. After about 10,000 rivets, I think I'm starting to get the hang of it.