Building the Tail Section

Starting with the Tail

It really is a matter of personal preference as to what section of the plane you should start with... and go to next for that matter. I made my choices based on what required ancillary items I had available at the time. In other words, I knew I wanted to start building, but wasn't ready to buy the motor, retracts, etc., so I started with the tail section. After that, I was able to move on to the fuselage and get it as far as I could without a motor in hand. I used this process as I proceeded throughout the project, knowing I wouldn't have the funds to buy everything up front, and just did it bit by bit as materials became available.

OK, I started out by screwing up!

Well I quickly got my first rude awakening about how much different building from just plans is from building with one of those jiffy little "instruction manuals" that come with a KIT. Three words... STUDY YOUR PLANS!

Never having built a "scale warbird" I was unfamiliar with a section of the horizontal stab that sticks out from the TE of the stab, making it into somewhat of a "T" shape. I jumped in and started gluing sticks quickly without paying attention and noticed this small section that houses the elevator joiner and control horn armature, just below the rudder. DOH! That section was supposed to be built while framing up the hor stab. Oh well, improvise I guess. After finishing the stab, I was able to build the missing section offline and glue it to the stab. This made me slow down significantly throughout the rest of the process.

Horizontal Stab

The hor stab is framed up from sticks in two passes. You start by building the "upper half" of the airfoil, flat on the plans, and then sheet it. Next, you flip it over and build the bottom half of the airfoil right onto the upper half, and then sheet it as well.

Pay close attention to the plans when sheeting, as some of the sheeting is laid over the perimiter framework and some of it is laid up to the framework. It's not all done the same way, so be careful to check closely on each stab before putting your sheeting down.

The stab tips are made by sandwiching a thin piece of aircraft ply to act as a stiffening "core" between two thick balsa blocks. This is all cut and sanded to shape and blended to the shape of the overall stab airfoil. There is also a section in the center of the stab where four 1/4" sticks from the vert fin/stab will slide down into two slots in the hor stab, joining them strongly together. I reinforced the area around these slots a bit when building this stab

Vertical Fin/Stab

The vert stab is framed up in the same fashion as the hor stab, building the left half onto the plans first and then proceed to the right half, building it up onto the left. The rudder tip was made from a solid piece of balsa sanded to shape, and the long piece that gradually slopes the fin down into the top of the fuse is also solid balsa.

Elevators & Rudder

The elevators and rudder are also built in the two-pass method, but with a twist. They utilize a thin ply core throughout, like the stab tips do. So instead of building right onto the plans, you'll have to draw up the plans onto the ply cores and build onto them. Also, since the control surfaces of the SBD are fabric covered, you won't be doing any sheeting here on the ele & rdr.

Running your Music Wire

The ele & rdr use 1/8" Steel Music Wire as axles/joiners running through the surface pivot points and out to the control horn bay of the fuselage. You'll find drawings on the plans showing you how to bend and solder 4 pieces of wire to form 3 unique "armatures" that will need ball links soldered on as well. Boy, oh boy was this fun! Bending 1/8" steel wire into tight little shapes can be an excercise in humility. Get these as close to plans as possible, since they barely will fit into the fuselage as it is.

The elevator joiner wire runs through the before mentioned "T" section of the stab and has a second piece of steel wire soldered onto it to act as a control horn. This joiner wire goes through two hardwood bearings in the "T" section which should be reinforced a little in my opinion (I did).

TIP: The 1/8" wire is too thick to fit through the holes in the #87 ball links. Also, 4-40 rods are too thin to fit tightly and in my opinion, too thin to handle the load demanded upon them. I think this is an error in the Bates plans, since there is no ball link made that accepts a 1/8" wire, but I believe that the 1/8" wire is correct.

So, my solution was to slightly file the very ends of the wire armatures until the diameter was about 1/64" thinner and would let it slide into the steel balls of the ball links. This fit tightly and made for good solder joints, and left 95 percent of the armature at it's original 1/8" diameter. Oh yes, if you do this... bend your parts first and then file the diameter down. Don't do it the other way around because once you file the wire, it will break when you try to bend it angles of 90 degrees or more.

Note that the latest revision of the Bates plans has completely redesigned the elevator control with pull-pull linkage and non-joined elevator halves.

Pictures of the control horn armatures in the last former "bay" of my SBD appear later in this section of the site.