Clecoing and adjust HS front spar

Posted Jan 13, 2024 2:00

By Fan Zhang

2 min read

Today I continued my journey of horizontal stablizer spar, HS-ASS-001-C-F-0 sheet 4, 5.

Clecoing

The parts are the longest I have dealt with so far, I cleaned out my work desk to make space and laid out all parts to be clecoed.

I actually found out that I forgot to clean and prime a few hinges when I did the initial cleaning. So I took care of that quickly.

Then I clecoed everything together. The spars were long and some parts are pretty thin. When I lift them it was shaky and twisty. It was a little nerve racking to be honest.

When working on rudder, VS etc, I found that many holes were not perfectly aligned, and sometimes I had to ream them to feed through the rivets. I really want to avoid this if possible on the HS spars. So this time I paid extra attention to the hole alignment before inserting clecos. Previous I was using the cleco as a guiding rod to align the holes, but I don’t think I should rely on that going forward. So I visually aligned the holes this time besides relying on clecos.

In one particular part, I believe it was the inner most rib (HS-RIB-005-X-A-0), 5 layers of sheet metal needed to line up prefectly. I just couldn’t do that. The rivet could not feed through no matter how many times I re-clecoed the parts. I switched to a different way later - I took a rivet and used it as a guide to line up the holes, then I put the cleco to fix the position. This actually worked. I was able to put through rivets without match drilling.

Measuring twist

The instruction says I should measure twist when skin is clecoed on. I haven’t dimpled the skin yet so not yet. But I still used a laser level to measure just the spars. I put a laser level on one end of the spar, verified the veritcal line touches the center of each spar rib except one (the outer-most rib). Then I verified the other end. The outer most rib (``HS-RIB-004-X-A-0`) was just off my a few millmeters. I didn’t try to bend or adjust, I am hoping this will correct itself when I have the skin on. I will deal with twist when fitting the skin in a few days.