Chapter 7 Mod – Installing threaded CL & sidewall ‘bungs’

Today I removed the few remaining toothpicks holding the Nylaflow conduit in place.  I trimmed the rudder cable channel of any excess & high micro, and then razor cut any excess foam & micro from the main gear extrusion bolt hole plugs.  I then sanded the newly emplaced foam/micro bolt hole covers to finish.

On the fuselage bottom I used 2 long AN3 (3/16″) bolts threaded into 2 aluminum threaded inserts (Note:  These inserts, or ‘bungs’, are also used to mount the bomb-looking baggage pods to the wings.) that would be mounted into the fuselage foam on the underside fuselage centerline.

Chap 7 Mod - Installing bottom fuselage CL mounts

Chap 7 Mod - Installing bottom fuselage CL mounts

I then taped the 2 bolts to a yardstick and then micro’d the 2 threaded aluminum inserts into two holes that I had already placed and drilled in the fuselage’s centerline—one fore and one aft of the landing brake.  Since there is a slight curve to the fuselage from fore to aft, I weighed down each end of the yard stick and then rechecked that the bolts were 90° to the fuselage.  Now “90° to the fuselage” with a slight curve means that they are not exactly parallel: the curve will create about a 0.5° to 2° offset between the bolts.  This offset will be manageable and the impact negligible.

Chap 7 Mod - Installing bottom CL mounts

Chap 7 Mod - Installing bottom CL mount

Chap 7 Mod - Installing bottom fuselage CL mounts


Chap 7 Mod - Installing bottom fuselage CL mounts

As I was preparing for the installation of the bottom centerline threaded inserts, I also prepped the right inside fuselage wall so that I could have a threaded hard point mounted inside the fuselage wall for mounting a rear seat component, mounting tab, etc.  This is located just behind the front pilot’s seat on the right side:

Chap 7 Mod - Installing fuselage sidewall mount

The pics below show the outside foam plug, with the micro (and a bit of flox) curing.


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