14 May 2014

Wing Ribs, End Ribs & Trailing Edges + Fuselage lashing trimming

Over the last couple of weeks, we've finished all of the wing ribs for the center and middle wing sections, and the end ribs for the center section.  We've also continued to build more trailing edges, and Chris cut the remaining trailing edge cores, including narrower cores for the outer parts of the tapered wing sections.

We also trimmed the lashings on the fuselage frame that had been lashed a couple of months ago.


Ribs and End Ribs


Working on wing ribs and end ribs


Cutting out main spar hole with hot wand


A bunch of ribs with spar holes completed (with some remaining below)


Cutting triangle of foam out for trailing edge


Sanding inside of rib caps after cutting out foam triangle


Cutting foam core for end rib


End rib after gluing and clamping of full balsa face sheet


Cutting rib caps to proper width for end ribs


Applying glue to rib caps


Spreading the glue


Rib caps in place, peel ply in place, ready to put into shuck and under vacuum


Taped up in the shuck


Almost ready for vacuum bagging, putting bleeder cloth over peel ply


Ready for vacuum


Under vacuum


After vacuum


After Vacuum with tape removed


Finished end ribs (and all Center and Middle ribs) with spar holes complete


Foam-only biscuits (i.e. foam plugs) 


All of the foam plugs (aka "foam-only biscuits") cut to length, ready to install into the rear spars



Prep for Flow Visualization Tests


We are getting ready to do some flow visualization with a Naphtha/Lamp Black solution, to see if we get good flow over a bare Depron surface (thus meaning we don't have to risk bending the Depron when heating the Mylar, and making application of the Mylar on the remaining open areas of the wing simpler).   So we did some compatibility tests with Depron and Naphtha to make sure that the Depron didn't melt (it didn't).



Compatibility test of Naphtha on Depron




Making Trailing Edges



Cutting trailing edge cores


Completed cores (narrower cores for tapered tips at right)


Cutting Polyethelene sheeting for trailing edge build


Heating and smoothing the polyethelene sheeting (after unfolding it)


Cutting the Kevlar fabric for the trailing edges


Putting the epoxy on the Kevlar


Spreading epoxy out (under Polyethelene sheet)


Putting base sheet down (peeling top polyethelene sheet, leaving bottom sheet over top of Mylar on long board)


Placing the cores on the bottom sheet



Cores in place (4 cores, 8 feet long each)



Placing strengthening patch over junction between 4 foot core sections (it goes under the top sheet, there is a corresponding patch on the bottom side as well)


Smoothing out the Kevlar into the valleys between cores


Adding the 'magic strips' -- polyethelene strips covering about 95% of width of the trailing edges to prevent too much epoxy from getting sucked out of upper layer of Kevlar under full vacuum


Ready for vac uum bagging -- peel ply and bleeder cloth in place



Ready for vacuum



Finished Parts


Trimming Fuselage Lashings


Unbolting hose clamps



Removing the tape on un-epoxied ends of Kevlar Tow



Cutting excess ends


Cutting excess ends with razor blades


Kevlar lashings after trimming


That fuselage is light! (approx. 2691.4 grams -- under 6 lbs!)




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