Brief Description: Drilling through the Tail Boom Bulkhead
During the week, Aaron put together a useful weights and balance spreadsheet to compute the actual moment arm to see if it falls within the prescribed MAC (mean aerodynamic chord) limits. A 10 pound tail ballast is necessary to keep pilots in the 180 - 200 lb range within the MAC limits. Rather than throw 10 pounds of useless weight in the tail, why not install the future battery and radio antenna to that area! Unfortunately I soon realized that my plans were thwarted by this pesky bulkhead about halfway down the tailboom that keeps the ruddervator pushrods in place.
The Monerai uses a custom thin-walled aluminum tailboom to join the Empenage (ruddervators) to the fuselage. Inside the tail boom are 2 large push rods used to control the ruddervators. Half way down the tail boom is a bulkhead, approximately 3/16" thick, that has 2 guide holes for the ruddervator push rods. There are no openings or extra holes in this bulkhead. The only way to get wires from the tail to the cabin would be to drill a hole through this bulkhead. Since I have no way to reach my arm 6 feet into the tailboom and drill a hole I had to come up with something clever. I went to Home Depot and purchased a 10 foot section of 1/2" copper pipe, trimmed it to 7 feet and made some bushings on the lathe to make a 7 foot long drill bit! The drill bit to be used was a 1/2" harbor freight stepper bit that had a hex shaft. So, the bushings had set screws to keep the copper pipe, bushings and drill bit in place. Using a flash light and a lot of patience I got the hole started at a place on the bulkhead that had the greatest spacing between the rivets. I even deburred the hole afterwards using ane even larger stepper bit. Now I have a 1/2" hole to route the positive battery cable, radio antenna, and future tail light wire.
