Finding a place to mount the 2 Lightspeed Plasma III CD Ignition boxes really got me thinking of how to mount them and still have access and room for the wiring. I decided to mount each box flat against the F-7107-L and F-7108A forward fuselage ribs. I purchased 6 feet of 6061 aluminum Z-Bar 1/2" high with 3/4" flanges. I cut 4 pieces 7 1/4" long. Two for each ignition box. I marked the location on the vertical flat of the left rib for #30 rivet holes. Three AN470AD rivets in each Z-Bar. I drilled the 6 holes, deburred and then match drilled to the left rib. The right center rib has a 0.125 3/4" x 3/4" angle riveted to it to support the roll hoop brace. This requires the 2 Z-Bars to be spaced out from the rib to clear the roll hoop brace angle. I made up a Z-bar from 0.032 aluminum angle riveted together with AN470AD-4-4 rivets. I match drilled this to the center rib for AN470AD rivets. To support the bottom of the Z-Bars I cut an 8" piece of 0.064 angle stock. I laid this on top of the Roll Hoop brace angle and match drilled 5 #30 holes for AN470AD rivets. I also drilled for 2 MS21047L08 nut plates that the 2 Z-Bars would be fastened to with #8 screws. I laid the 4 Z-Bars on a table and laid the ignition boxes on top to mark for 4 nut plates that would secure each ignition box. I drilled all the holes and countersunk for AN426AD3-4 rivets. To support the bottom of the left rib Z-bars I drilled #21 holes for AN3 bolts through the #2 comm radio support angles and through the 2 Z-Bars. I cut a 2 spacers from aluminum tubing that would take up the space between the Z-bar and angle. I primed and riveted 10 nut plates and riveted and screwed all the pieces to both ribs. Using AN3-13Abolts I secured the Left Z-bars to the Comm 2 radio support.
