Horizontal stabilator Part 1/4

Today I also did a lot of work on the Horizontal Stabilator.  All of the HS doubler and spar countersink holes were drilled earlier this week while I waited for paint to dry..  so today's progress was good.   Here is what we're building:

Today's work consisted of building the spar box -- thats the HS-1202 Forward main spar, HS-1216 Aft main spar, HS-1211 x 2 (top and bottom).  There are 4 square ribs inside the spar box and some doubler plates.  Since good progress was made, here's today's video:

More progress was made today after the video such as match-drilling the upper and lower control horns, match-drilling the counter-balance flanges on the forward and aft side of the spar box, match drilling the counter-balance arm..  disassembled everything and deburred.

Drilling through steel (the counterbalance arm) was tough.. unwelcomed change from drilling through aluminum for the past two weeks!  

There was a little art involved when drilling the CB arm.  Remember, here is what is looks like upon final assembly:

They have you rotate the arm and the two flanges for it by 90 degrees.  This is so that you can drill holes into the flange & arm straight down.. rather than sideways.

So the deal is to insert the arm through the front flange.. and then through the back flange.. until the arm is flush with the back flange.  Easy enough...  but then you have to rotate the arm so that the flat end of the arm is flat, like you see in the above diagram.

I had a digital level which measures down to 0.1 degrees..  I placed it on the spar box and it read 0.5 degrees (i guess my workbench isn't exactly level.  I then placed it on the flat end of the counter-balance arm... I rotated it until it also read 0.5 degrees.  I used a C-clamp to lock the arm in place (to the rear flange)..  then started to drill #30 holes, then final-drilled #12 holes.

Tomorrow, I should be able to get the spar box done and all the ribs attached.  Doesn't sound like a lot, but I haven't prepped or painted any of tomorrow's parts yet..  After that, i'll be stuck until I get a piano hinge... but hopefully my shipment will come by then.