Sunday, October 28, 2012

(Page 21-15) Waiting for the Oracle to speak........

The vast expanse of aluminum known as the bottom skin is clecoed (only a few are shown inserted, a few hundred will follow), the various doublers and stiffeners are in place (the triangular pieces around the inspection plates and the unseen pieces that connect them), but I'm reluctant to rivet it all together because of the pending fix for the landing gear problem.  The Mothership has published a diagram showing where not to rivet in anticipation of the fix, but I'm still nervous. There are many hundreds of rivets that go into bottom skin, and I'd hate to have do drill them out.

There's a two-month lead time on the wing kit, so I plan to order it tomorrow.  With Christmas break coming up, I'm thinking I can finish the fuselage before the end of December.

Thursday, October 25, 2012

(page 21-13) Inserting the column...              


The control column (the horizontal shaft to which the joy sticks are attached) is nicely powder coated, and this powder coat must be removed from the bolt holes to allow the bolts to fit.  The instructions say to "finish drill" the holes with appropriate bits, but the center line of the holes is too close to the column to allow the drill body to fit.  Since paint is being removed rather than metal, a drill bit wrapped in tape worked well.

The challenge was inserting the control column through the lightening holes in the floor ribs (click on the picture and look at the lightening holes in line with the vertical red stripe on the cabinet in the background).  It seemed, for the first 15 minutes spent attempting this, that it wouldn't fit (not helped by the fact that I initially had the column backward).  The various ears welded to the column have to be rotated just so as each lightening hole is approached, and a fair amount of displacement normal to the column axis is required.  I nicked the power coat several times in the process, but that seemed unavoidable.  Once the column was in place, the real challenge revealed itself: getting the bolts through the ear holes and bearings with the appropriate washer stacks in place.  In retrospect, I should have super glued the washer pairs together rather than trying to tape them as suggested in the plans.  Turning the fuselage on its side helped.

Sunday, October 14, 2012

(page 21-10) Double flush?.........              

Forget the commode jokes.  The bearing bracket for the control columns requires that the rivets holding together the plates which sandwich the bearing be squeezed "double flush."  I had no idea how to accomplish this, and, in fact, had never heard this term before.  It's pretty easy to imagine what it means -- nothing should protrude from either side of the rivet hole.  Beyond the rather descriptive name, the build manual offers no clue.  Homebuilt Help video to the rescue.  Turns out you countersink each side of the hole, then squeeze the bejesus out of the rivet.  The shop head sort of conforms to the cone-shaped countersink (red arrow in the pic), but still protrudes a bit.  Apparently this is OK.  I don't know yet what part needs clearance here.  As usual, all will be revealed later in the build.

All the riveting beneath the seat floor and baggage compartment floor seemed to go well for the most part.  One particular nutplate, however, required squeezed rivets I couldn't reach (red arrow in the pic -- the rivet is below the horizontal flanges with the already-squeezed rivets).  The "no hole" extended reach, close quarters arbor for my Main Squeeze from Cleveland Aircraft Tool saved the day.  Pricey, but only way to do the job ($120 for the arbor alone).  Airplane buildin' ain't cheap.  I'm figuring I'll have at least $70k in this mofo before it slips the surly bonds of earth sometime in 2014.

Friday, October 5, 2012

(page 21-10) Don't build fuselage before wings...                     

...or at least buy the two kits at the same time (which I couldn't afford).  As described previously, for the rear stub spar, I had to file a "receptacle" in the fuselage kit to fit perfectly with the corresponding part in the wing kit -- which I didn't have.  I solved the problem by ordering the wing part from Van's and doing the requisite filing.  Why I didn't order the part for the front stub spar at the same time, I don't know.  I knew it was coming.  Trying to order the parts this time resulted in getting two sets of wrong parts, owing to a misunderstanding of what was needed.  This was a result of trying to work it out via e-mail rather than sitting for a while on hold (in fairness, it's usually not that long), then talking with someone in builder assistance.  It's all squared away now (I hope).

The bigger news is that the Spousal Unit (my beautiful and uber-smart wife, Karen, shown here with Drs. Parsons, Rhyne, Thomason and Hill at a celebration in the mountains of Virginia) successfully defended her Ph.D. dissertation in mechanical engineering ("A semi-quantitative schlieren high-speed flow diagnostic: analysis of high-pressure-ratio, over-expanded planar flow in rocket nozzles").  Now, the earth can resume spinning on its axis, the birds in the trees can once again sing, and the universe can breath a huge sigh of relief.  I hope to never again (or at least for a few months) hear the phrase "weak oblique shock wave."  There are good points and bad points to having a wife whose area of expertise is the same as your own.

How does this relate to building my airplane?  I should have a lot more time now to devote to that effort.  First flight is planned for 2014.