Thursday, September 20, 2012

Rolling The “Canoe”

A momentous moment at DOG Aviation … rolling of the “canoe” as it is called in the world of Van’s aircraft builders.  The tail cone “canoe” was successfully rolled and placed in the upright position on the workbench without incident.

Admittedly, rolling the RV-12 “canoe” is not much of an event when compared to my friend Pete’s RV-9A canoe rolling. Nevertheless, it felt the same … a joyous moment, celebrating yet another level of accomplishment.
                           Jan helping out with the rolling of the RV-12 tail cone “canoe” to the upright position.
                       Tail cone “canoe” sitting upright ready for the aft bulkhead and more skins to be attached.

Now that the “canoe” has been rolled there is a need to fall back a little in the instructions to finish up the rear bulkhead’s F-1211C hinge brackets. The hinge bearings require being match drilled to the F-1211C hinge brackets and aft bulkhead assembly.
                             Match drilling the hinge bearings to the F-1211C brackets and aft bulkhead assembly.

I’ve been holding off working on the hinge bearings and hinge brackets because I was initially planning on using solid rivets to attach the brackets to the F-1280 side skins. However, the sticky wicket is in order to do that, the bearings would have to be riveted onto the hinge brackets AFTER the brackets are attached to the skins because of reach limitations of the pneumatic squeezer.  Quite a gamble, but one I was willing to try taking because of the precision of Van’s parts manufacturing thus far. Of course, if solid rivets were used, the holes in the hinge brackets would have to be countersunk to 100 degrees as opposed to 120 degrees necessary for countersunk pop rivets.

The tipping point for my decision NOT to use solid rivets to attach the hinge brackets to the F-1280 side skins was the instructions. The plans are calling for the mating of the aft bulkhead/hinge bearing assembly to the previously assembled stabilator to determine the washer spacing and thicknesses required for free movement without binding. This is done prior to the aft bulkhead being attached to the tailcone. Once the washer thicknesses and spacing is determined, it will be documented and used later for final assembly. In my mind that is important ... because if I were to assemble with solid rivets, that test would not be possible and it would truly be hard testing the fit later using the stabilator as the moving part as opposed to the much smaller,lighter and easier to handle aft bulkhead/hinge bearing assembly.

Once the final decision was made to pass on the solid rivets, the hinge brackets needed to be countersunk for the 120 degree countersunk pop rivets using the countersink cage on the drill and a drill press for the inside row of holes which the bend in the hinge bracket prevented the countersink cage from sitting flat.
                          Countersinking the F-1211C brackets for flush rivets where the F-1280 side skins will attach.
                             Machine countersunk hinge brackets along with the match drilled hinge bearings.