Worked a few hours today creating more aluminum shavings and dust while finishing up the AEX tie down extrusion and preparing the tail cone bulkhead doubler plate. The tie down extrusion was shaped yesterday and all that was left to do was to drill out the hole to the proper size for a tap which was run down the hole to put in the threads the tie down ring will screw into.
After the tie down ring was completed, began
working on the tail cone’s aft bulkhead doubler plate which required the
removal of four manufacturing tabs on the band saw and some serious deburring ….
the metal required lots of filing and sanding to remove all the burrs from manufacturing.
Deburring the tail cone bulkhead doubler plate
on the Scotch-brite wheel.
Emory cloth wrapped around a file to smooth the
edges of the slots on the bulkhead doubler plate.
Once the edges and cutouts on the doubler plate were
all smooth, the countersink bits were brought out for the 16 #40 and 3 #30 holes
that require machine countersinking.
Machine countersinking the 16 #40 holes in the tail
cone bulkhead doubler plate.
A couple of days ago while digging out the rivet
gun I ran across a bottle of liquid Boelube I forgot about purchasing way back
in March. For those not acquainted with Boelube, it is a lubricant Boeing came
up with for use on drill bits and cutting tools to make them last longer and it
seems to make the drill cut better as well. The form I’m most familiar with comes in a
plastic container and has the consistency of crumbly wax. As the drill bit
spins, it has a tendency of flying off the drill bit and getting it on a
countersink blade is … well, problematic at best. The upside is that it is a
dry lubricant and does not leave an oily mess after the hole is drilled.
The liquid Boelube is more of an actual
lubricant and performed great while cutting the threads into the AEX tie down
extrusion which the tie down ring will screw into. I also placed a drop on each
hole that was countersunk and had great results.
The 16 countersunk nutplate rivet holes on doubler
the liquid Boelube used on the holes prior to countersinking.
Tail cone parts ready for a few rubs with a Scotch-brite
pad then priming.