First the lens was coated with painters tape to prevent unwanted scratches while working on it. Knowing that quite a bit of material is ultimately removed from the lens, the outer edges of the lens were zipped through the band saw to remove the portions of the lens that were raised from the bending process … while at it, most of the material that would ultimately be removed anyway was also removed. Now having flat Plexiglass to work with made the rest of the process much simpler than last time.
Using the band saw to trim the excess material
off the landing light lens prior to reforming the lens with heat.
Earlier in the morning the DOG Aviation R&D
department played around with scraps of Plexiglass from the first lens after
placing painters tape on them. It needed to be determined if using a heat gun
would fuse the tapes glue into the Plexiglass when it got hot enough to reshape
a bit … it does not.
Donning a pair of gloves, the lens was heated up
with a heat gun set to low until it was good and hot (but not pliable soft or
almost melting) and the bend was gently relaxed a bit. The Plexiglass was given
a good heating a second time and then pressed up against the leading edge of
the wing to cool … it dawned on me the perfect shape the lens needed to be was
sitting right in front of me … staring at me. Because there is a tendency for
thicker Plexiglass to want to go back to its original shape, the process needs
to be repeated a few times. The end result was a much faster and better initial
fit than the lens for the left wing.
Holding the hot Plexiglass lens firmly up
against the wing’s leading edge
to cool so the lens gets reshaped to match the
wing's leading edge curve.
After the landing light lens was reshaped, it was
placed behind the cutout in the W-1203 skin aligned for best fit then drilled
and secured with Clecos.
Match drilling the right wing’s landing light
lens to the holes in the W-1203 skin using a special Plexiglass drill bit.
The landing light lens was drilled to #30 then the
holes are re-drilled to #27 because screws will be going into the lens. After
drilling the holes out larger, the lens needs to be machine countersunk. This
is because the W-1203 skin gets dimpled for a #6 screw … that dimple will rest
into the countersunk portion of the lens. The #6 screws that secure the lens have
a 100 degree taper so the #27 countersink bit was installed into the countersink
cage and all the mounting holes in the lens were machine countersunk to accept a
#6 dimple. A scrap piece of aluminum was dimpled to a #6 for the purpose of
being used as a gauge to set the countersink cage to the proper depth for machine
countersinking the lens holes. After the
right landing light lens was countersunk, the left lens was removed from its
resting place and also countersunk.
Using the countersink cage with a #27 bit to machine
countersink
one of the landing light lenses clamped onto a piece wood.
