Bolting the vertical stabilizer onto the RV-12’s tailcone.
Being exhilarated after bolting the vertical stabilizer onto the tail cone was short lived ... noticed in the prints that the mounting hardware was not to be tightened. Apparently all the tail feathers are to be assembled to check for freedom of motion then disassembled to work on the fairings. Reading ahead to chapter 12 it appeared as though all the tail feathers are removed so work can begin on fitting the VS-1213 vertical stabilizer and R-1206 rudder tip farings. There is even some trimming that needs to be accomplished prior to attempting a trial fit.
The cut lines marked in red on the VS-1213 vertical stabilizer and R-1206 rudder tip fairings will allow the fairings to seat properly.
When removing the fiberglass, my suggestion is don’t use your good abrasives such as stone wheels for edge work. They will work well for a few minutes then as the epoxy begins to melt from the friction, it will clog the abrasiveness of the tool … and presto, it is toast. I used a Dremel outfitted with a cutting wheel along with sanding drums with 80 grit sandpaper. A sanding block with 80 grit sanding paper uas used for hand sanding to the scribe lines.
R-1206 rudder tip fairing fully seated and ready for drilling.
After the fairings are trimmed to seat properly the VS-1213 fairing receives a little more attention by way of removing material to create a recess for the rudder faring. The builder is instructed to purposely leave 1/8" more material than necessary along the aft edge of the fairing then mate the rudder onto the stabilizer and remove material until there is a uniform gap of 1/8" between the two fairings through the full range of motion of the rudder.
Aft edge of the VS-1213 tip fairing is left a little long and is to be sanded down to match the edge of the stabilizer skin.
VS-1213 tip fairing requires much more finessing in that a recess in the fairing needs to be made for rudder clearance. Note the red dotted lines are approximately 1/8" beyond the pencil line (which is the scribe line). The amount of material removed in this area will be based on the rudder movement.
Scribe line is in pencil the extra 1/8" line is in red.
Because the rudder rivet holes for the R-1206 rudder tip fairing have already been dimpled, it will be necessary to countersink the rivet holes in the fairing after they have been drilled. This will weaken the fiberglass and leave not much material for a rivet to grab, so thinking about adding some thin aluminum backing strips or aluminum washers for the rivet to set on. This will not crush the fiberglass as the rivet begins drawing down onto the fiberglass. At this point in time, I’m leaning towards just using a little fiberglass resin to either stick washers onto the backside of the tip faring or just epoxy a thin strip of metal down for a backing prior to match drilling. Have placed an order for the necessary materials to do the canopy … so for the time being, I have set this aside and will wait for the fiberglass materials and ponder the situation in the meantime.
Moving on, the tail cone fairing receives some attention. First, four templates are drawn onto masking tape and stuck onto the aft portion of the tail cone skins. These templates are used to determine the location for the holes mounting the fairing onto the tail cone. The fairing itself gets cut up big time and there are holes that need to be drilled into it.
Left top and bottom templates drawn onto masking tape. The lines with the X are drill points for securing the fairing halves.
Prior to cutting the F-1294A and F-1294B tailcone fairings, a few #30 holes are to be drilled into the fairings along with a few 3/4" holes.
Using a step drill to drill a 3/4" hole into the F-1294B bottom tailcone fairing.