Source: 2019 Q4 Beartracks, Mark Goldberg
Over the last year and a half, we have made a number of changes to the kits. The purpose of this write up is to detail the most recent changes we have made in the Quick Build kits.
But first, let me go back to May 2018 to begin. Bob Barrows made the trip to the kit factory with me back then. We successfully showed the workers some new tricks. Really three things:
1) Bob showed the guys how to drill the wings to the fuselage and drill the wing struts.
2) Bob showed the workers how to make up the fuel tank straps and install the fuel tanks in the wings with the filler neck sticking out.
3) Bob calculated the lead weight needed for the elevator’s counter weights when the elevators are covered with the lightest fabric, Oratex. The lead is melted and installed on the elevators. Room is left for more lead/epoxy slurry if a builder uses a heavier fabric process or sprays a lot of paint.
More recently, we made two additional changes to the kits. Ever since kit production began in 2001, many builders have modified the ceiling for a skylight instead of a fabric ceiling as Bob intended. Our intention was to come up with a ceiling modification where a skylight could be installed with no modification but fabric could continue to be used for those of us suffering through the heat of summer down South. Bob designed a system using 5052 aluminum of .050 as used on the fuel tanks.
As you see in the pictures, the very easy installation is to slide the Lexan in from the side for the two outer panels. The Lexan is captured on three sides by the channels made from the aluminum. This ceiling retains some of the “hump” in the middle so the fabric will behave if an all-fabric ceiling is installed. The aluminum channels are held by three “stand offs” welded to the tubing as opposed to the two that previously connected the ceiling to the tubing. After sliding the Lexan into place, it is screwed down to the square tubing above the upper longeron that follows the shape of the upper wing skin. It is recommended to use bigger holes (like 3/16”), then bush a #6 screw with nylon or rubber line. This helps prevent cracking as the Lexan expands and contracts differently from heat and cold than the steel or aluminum around it.
It should be possible and easy to install a Lexan panel on the center section also. A builder would use two additional pieces of the channel but facing the opposite direction of the existing channels running front to back.
At the factory in December, per Bob’s instructions – I showed the workers how to final drill the aileron and flap hinges to their spars after placing the ailerons & flaps in their correct positions.
Detailed photos of the new skylight accomodations: