Match Drilling The WD-1214 Flaperon Torque Tubes

Van’s RV-12 assembly plans instructs the builder to droop BOTH the left and right flaperons 1/8" prior to match drilling the flaperon torque tubes … so the metal shim pieces that were made for the occasion were used to create the droop. Using the sandwich method mentioned in the previous post worked out quite well and ended up being quite stable.

After the two 1/8" shims were in place and the flaperon drooped 1/8", pieces of flat bar stock were placed above and below the shims then clamped in position, sandwiching the shims in place.

A 1/8" thick piece of aluminum was used to verify that the correct amount of droop was achieved at the trailing edge. Looking good!

The right flaperon drooped 1/8".

After the flaperons were in a drooped position, a spacer 1/16" thick is placed between the WD-1215 flaperon torque arm and WD-1214 flaperon torque tube and the assembly is clamped for drilling. Prior to drilling, the WD-1214 torque tubes are to be positioned so the end of the tube is flush with the inboard edge of the WD-1215 torque arm. It was verified the torque tube was sitting flush on the spacer at both ends of the torque arm. At this point, the flaperon droop was verified once again and then flaperon torque tube was match drilled .

With the 1/16" spacer inserted between the WD-1214 flaperon torque tube and WD-1215 flaperon torque arm and verifying the torque tube is flush with the inboard edge of the WD-1215 torque arm the assembly is clamped for drilling.

Completed match drilling of right WD-1214 flaperon torque tube.

The above process was repeated to droop the left wing’s flaperon and match drill the flaperon torque tube. Now the wings will need to be removed so the bottom holes in the torque arm can be matched drilled into the flaperon torque tubes and all the holes enlarged to #12 so AN3 bolts can be inserted.

About to verify the left flaperon droop using a piece of 1/8" aluminum prior to match drilling the left flaperon torque tube.

This will be the last night the wings are left on until the RV-12 gets closer to completion. It will be much easier to move around the hangar without them getting in the way.