Friday, September 14, 2012

(page 21-07) Unhinged............                

After successfully match drilling the aforementioned seat back hinges, I proceeded to rivet them to the floor.  Unfortunately, I skipped one step -- removing two "eyes" from each hinge -- which must be done (obviously) before riveting (red arrows in the picture).  I therefore had the pleasure of drilling out 28 rivets in order to correct my error.  The band saw quickly removed the unwanted eyes and the ScotchBrite wheel (my new BFF) quickly deburred everything.  On the bright side, they were pulled rivets, which are way easier to remove.  I'm becoming quite the expert at drilling out squeezed or pulled rivets.

I'm longing to build some parts that the average person would identify as airplane parts.  Wings maybe?  The problem is this: Until all these parts spread around my garage coalesce into a fuselage, I don't have room to build wings.
(page 21-04) Little boxes..........                                  

The flaperon mixer assembly, pulley bracket assemble, baggage compartment ribs, floor ribs, etc., go together fairly easily with little confusion once I wrapped my head around the fact that some ribs labeled -R go on the left side of the airplane and some labeled -L go on the right side.  I guess they had a reason for doing this.  The discovery of this caused me at one point to think I'd made a massive error, but the pictures are quite clear about where everything goes.  Lots of nutplates to install, meaning lots of dimpling and lots of squeezing 3/32 rivets.  Things came to a brief halt on page 21-05 when reference was made to installing the autopilot bracket by referring to Section 39, which I thought I didn't have.  Turns out, a separate bag contains all hardware and instructions (Section 39).  Problem solved.


Real problems didn't materialize until page 21-06 where piano hinges have to be drilled for the seat back attachment to the floor.  My prior experience with drilling piano hinges was not a good one, resulting in a re-order from Van's.  Sure enough, the first hole I match-drilled through the hinge was off center (see picture).  The problem arose because the hinge is so far from the edges of the floor that it can't be clamped in place, and you can't see the hinge while drilling.  I solved the problem by sandwiching the hinge tightly between the floor panel and a 2x4 stood on edge.  Fortunately, I had an extra six feet (!) of hinge from my previous hinge misadventure.

Monday, September 3, 2012

(page 21-03) Baggage compartment floor...........                          

...yet another near disaster averted.  After reasoning out which holes required which of three dimple dies earlier, I somehow convinced myself that the dimpling of holes should have been symmetric left to right (it's not) and was ready to drill out approximately 30 rivets to correct my non-existent error.  Feeling disgusted, I took a break and went for a 20-mile bike ride, during which the increased blood flow to my brain caused me to realize I had done everything correctly the first time.  This project can be stressful.

After attempting to align rivet holes drilled individually through several relatively thick parts, it's often difficult (or impossible) to insert the rivet.  For the skin-to-rib holes, a 1/8th-inch drift usually lines the holes up enough to rivet.  For thicker parts (shown in the picture) this frequently won't work.  A chuck removed from an old drill (containing a #30 bit here) works well to twist the bit through the recalcitrant hole by hand.