(Page 40-01) Cutting holes for the lighting kit

I'm beginning to seriously question my decision to install the lighting kit: way more time than anticipated.  I'd probably skip the landing light if I had it to do over.  All three holes have full-size templates included in the build manual.  First step was to photocopy these and double check that the copies overlaid exactly on the originals.  I have in the past encountered copies which were slightly bigger than the originals.

I also think that paper expands or shrinks a bit with changes in atmospheric moisture, not good when the rivet holes shown on the templates have to match up with pre-punched holes in the hardware (landing light).  The holes for the wing-tip strobes are not critical since they will be covered by the fiberglass fairings which the strobes actually attach to.  In fact, the large hole specified could be replaced with a 3/4-inch hole easily done with a step drill.  A large hole is specified because the write up for the entire lighting kit assumes that the kit is being installed on a completed airplane and there's a need to reach in to the wing tip enclosure.  This job is made considerably easier when done during the build process.  In fact, it's hard to imagine doing the landing light installation after the fact.  The strobes wouldn't be a problem.

I cut out the cross-hatched areas in the template with an Exacto knife, taped the template to the aluminum, marked the hole with a Sharpie, then cut out the metal with an abrasive disk in a Dremel tool.  The last cutting pass was with an abrasive drum in the Dremel, followed by a 2-inch Scotch Brite wheel in a die grinder.  If I were doing it over, I'd put the Scotch Brite wheel in a drill since the die grinder has the potential do damage owing to the high speed.  Although the build manual doesn't say this, the template obviously must be flipped over when going from left wing to right wing.

I followed the same procedure with the landing light cut out.  This required temporarily clecoing the appropriate wing skin to the ribs, then making the cut.  I once again used the Scotch Brite wheel in a cordless drill for final smoothing, and was quite pleased with the results.  The problems arose after I drilled the rivet holes, which have to match up with stiffeners which have the holes pre-punched to accept nut plates (to be detailed in a following post).

The cut was tedious, the good thing being that there's only one of them.

The Scotch Brite wheel can be seen in the cordless drill.  I should have ordered one of these small wheels much earlier in the build.  From the start of the build I have made extensive use of a six-inch Scotch Brite wheel in a drill press for deburring, but access is limited for large parts.