Fuselage side walls - prep

For the side walls, I started out by cutting the 0.8" thick H45 Divinycell foam boards down to 23" wide. This would give me the extra panel I needed to glue onto the back to complete the 103" length required. I used packing tape to temporarily hold the pieces together before they are wet micro'd together.

Taping the boards together makes it very easy to glue them together. Especially if you don't have anyone helping you. You simply use the tape as a hinge like so.

Then pour wet micro in the groove.

Then lay the panels flat and let the excess micro pour out.

Then squeegee it for a smooth clean bond.

Once the micro had dried, I sanded the top edge flat. I then used the measurements called out in the plans to draw the bottom loft line (measuring from the top).

To help me loft the bottom edge line, I inserted nails into the foam and forced a long scrap foam board up against the nails. This gave me a perfect loft line to trace out.


Here's the result of the lofted line.

Since the fuselage walls are mirror images (with the exception of the right wall control side-stick recess; shown later on), I repeated the gluing process above. After it was cured, I placed it underneath the wall with the markings and match-cut them to size. I used a knife to cut the foam, intentionally leaving about 0.25" overhang.   

I then used a sander to fine trim both fuselage walls equal. Again, I left an overhang (about 0.1") so that I could later flush trim the foam and fiberglass flush with the longeron edge using a router after completing this chapter.

 And presto! Two fuselage side panels!

The plans calls for an 8" diameter recess located on the inside of the right fuselage panel. This is to give the pilot more knuckle room when controlling the side-stick. To do this, I started out by tracing an 8" diameter circle using a compass (centered 7" below the top longeron and 7" aft of the instrument panel). 

The plans say to remove 0.5", so I took out my handy router, and adjusted the bit height accordingly.


Here's the router removing foam material. I didn't have a circular guide, so I had to eyeball it.

I love this router! I can't imagine having to do this any other way. It removed 0.5" exactly (I used my digital caliper to verify!)

 I then used a 45 degree bit to help get started on my transition.

I then sanded the edges round and presto... a nice 8" diameter recess!

I should note that I did not make the fuel site gauge depressions at this time. This is because I might incorporate a mod that has you cut the passenger storage compartment cutouts (on the fuselage sides) a few inches further aft. This gives the passenger more elbow room. The fuel gauge would simply be relocated slightly inside the storage compartment (yet still be visible to the pilot during flight).

I decided to keep working and so moved on to prepping the longerons, stiffeners and LWX/LWY pieces. I used a 1/4" router bit to radius the top edge of the top longerons. Do not radius the lower lip just yet; you have to wait to install it so that you can radius it WITH the stiffener. I didn't bother trimming them in length since Aircraft Spruce had shipped them to 104". The plans say to leave a 0.5" overhang in the back... I figured it couldn't hurt to leave it an extra inch long for now; regardless, it will be trimmed when the firewall is installed in the following chapter and will make for an easier installation.

Here I am using my band saw to trim the stiffeners. I created a jig to hold the stiffener to an approximate 5 degree angle.

(UPDATED NOTE: while working on Chapter 21 - the strakes, I noticed I installed a 0.5" thick stiffener. The plans show a 0.4" thick stiffener. At the time, I thought nothing of it and installed the 0.5" thick strip. Problem with that is 0.1" will have to be milled later in order to make the cutouts for the baggage compartment cutouts - see plans pg 21-2. Not a big deal, but if I were redoing it, I would have purchased a 3/8" thick strip instead of 0.5").

They came out beautiful!

While I was at it, I figured I would prep the lower triangular longerons as well. Here I am using my drill press to make holes for the positioning nails (one hole every 6 inches). 

LWX and LWY - I didn't have 2" spruce, so I epoxied two 1" pieces as indicated in the plans. I let them cure overnight, held together by clamps.

The next day, I cut the LWX and LWY pieces to size. Similar to the top longeron, I intentionally left the LWY pieces extra long. Here is a pic of the left and right LWX and LWY pieces.

I started to cut the fiberglass cloth that will go on the inside fuselage walls. The plans calls for UND at a 30 degree angle... this took up a LOT of counter space.

Here I am test fitting the cut cloth.

Now that I had all the cloth pieces cut to size, I marked them so that I knew which orientation they had to go before rolling them up. Good thing I did this! It saved me a lot of guess work later on when it came time to actually glass it!