Re-covering tail, Balsa prep and Fuselage tube shaping

Here's a quick post on the work we've done in the last month up to Thanksgiving.

Among other things, we've done some re-covering experiments with the tail, we've prepped and laminated all the balsa for the remaining biscuit doublers for the plane (mostly for the main wing spar and tail boom), and we've shaped and fitted most of the tubing for the fuselage and made composite sandwich gusset material for the bottom bracket in preparation for lashing together the entire fuselage frame.

Not shown in the photos below are the cleaning and prep of the main wing spars and tail boom for biscuiting (we're about half done with that), and also all the CAD work we've continued to do in order to create all the cut files for the ribs and rib doublers (we have the files for the wing root ribs done, which will let us start building the plane from the 'inside out' since the three middle and center sections of the wing all use one rib profile, but we have 32 unique rib profiles that need to be completed, along with all the doubler files, in order to build all the variations of the tapered outer wing sections).

Cutting Mylar to fit the tail surface

Trimming Mylar

Tightening the Mylar covering on the test Vertical Tail surface.  We've only used regular Mylar so far, which doesn't shrink a lot and leaves wrinkles over the leading edge.  We'll try tensilized Mylar in the next few weeks, as it seems to shrink better, in order to see if we can get a smoother surface on the leading edge.

A sample decal in place.  We'll use this same process for sponsor's decals on the fuselage.

Cutting balsa to laminate two sheets with ~20 degree angle between grain of each sheet.

Laminating two balsa sheets at ~20 degree angle to each other.  The finished sheets will be laser cut to make biscuit doublers (in a balsa/foam/balsa biscuit that goes inside the carbon fiber tubes).

Initial cutting of the miter shape into the carbon fiber tube, using a paper template.  We leave a bite extra and sand to the finished shape in an iterative process while fitting multiple times as we sand.

Underlying balsa after removing the carbon fiber.

Cutting the bulk of the excess balsa plug off prior to sanding.

Sanding the balsa plug and edges of the carbon fiber to the final miter shap (aka "fishmouth shape'), using a paper template as a guide.

Final sanding of edge during fitting

Fitting a tube miter on the Fuselage Frame (Chain Tube to Top Tube)

Fuselage Frame with 4 of the 5 main tubes fitted and ready for tacking and lashing

Carbon fiber-Nomex honeycomb composite panels under vacuum (one is 1/16" thick, the other 1/4" thick -- these are to be used as gusseting material for the bottom bracket attachment to the fuselage frame at the Chain Tube).

Completed CF/Nomex panels

Hot wired root airfoil sections, ready for rib cap laminations

3D Print in ABS of the hook on the Lift Wire Clamp, to test sizing and fit with the sailing thimble used at the end of the lift wire.  (actual part will be machined out of aluminum and will include 'wings' that get lashed onto the main wing spar).