Trim Tabs Complete

I finished the trim tab a.k.a. AST a.k.a. anti-servo tab a.k.a. Flettner tab last week.  I'm finally getting around to posting the pics.  I also have advice for -12 builders to pass along that didn't get mentioned in my previous posts.

Firstly the CFO picked me up a pair of clamps from Harbor Freight on sale for two bucks apiece.  Do I have an awesome wife or what?!  They came in handy for holding up the trim tabs for final riveting:

And here it is getting all buttoned up with the pop rivets:

And now for the builders advice.  It should be obvious but in case it's not, you should be using this squeezer yoke for riveting on the horns:

and not this one:

I mention it because how I was going to rivet on the AST horn (top picture, right side) was a bit of a head-scratcher 'til I figured that one out.  The other advice I have for riveting the AST horns is to only give 'em a half-squeeze 'til all five rivets are in.  Then go back and squeeze 'em down to final size, but not too hard.  It just seems to work better with the thin aluminum AST rib doing it that way.

And here they are:  Two halves of the AST trim tab, which will eventually go at the back of the back of the plane:

Tah-daah!
Up next:  Section 9: Stabilator

Another AST Oops

Page 8-3 has you disassemble a length of piano hinge by removing the hinge pin and then trimming the two halves to the prescribed length.  Then you drill 33 evenly-spaced holes to match the pre-punched holes on the AST skin and spar.  To drill the holes in just the right place Van's provides a nifty drilling template shown in the picture:

The bottom hinge half is the one I drilled before I carefully read the instructions.  The top hinge half is the way it was supposed to be drilled - with one row of holes, not two. 

Another 15 bucks down the drain.  Sigh.

Warning to other builders:  Before you start on this, use a Sharpie to cross out the upper row of holes on the drilling template.  If you're a tired it's entirely possible to repeat the above "oops" again.  Don't ask me how I know.  And if we ever meet - don't bring it up.  It's embarassing.

I'm trying to decide whether to include the cost of my screw-ups in the cost tally -- it's not really fair to Van's to inflate the airplane building cost.  The CFO says "Yes."  "Definitely yes."

AST Oops

This is an AST trim tab spar.  Nuthin' fancy - just a piece of angle aluminum with pre-punched rivet holes spaced about an inch apart.

Here I'm spraying it with primer "just because".

Here it is leaning inside the garage door track, you know, so it doesn't fall over between the first and second coats:

This is me getting distracted and completely forgetting about the AST spar (wait for it...)

And here's the 150 lb garage door closing on the spar still leaning inside the door track:

OUCH!

Tried to bend it back into shape but it's a goner.  No way the precision-punched holes will match up to the holes on the trim hinge or the skin.  So it's $8 to replace three soda cans worth of aluminum angle + $7 shipping from Van's.