06-13-2011: 2.5 hrs
Finished trim tab, riveted hinge to both trim tab and elevator. Fitted trim tab to elevator. Left elevator is almost done. Just need to bend the leading edge and safety wire the hinge pin. I back riveted some of the trim tab horn to trim tab rivets and got good results. Today's work is eventless except riveting the outboard bend of the trim tab. The drawing calls out CS4-4 rivets for all trim tab bends, the edge margin is pretty small, and I almost got zero margin for one of the two outboard bend rivets. However, the load in this area is very small, I will keep as is and add it to a "frequent check" list.
One rivet is added to address the short edge margin issue on the outboard trim tab horn
Piano hinge on the trim tab side is drilled. The edge margin is small, but it is per drawing dimension. Consider the load and number of rivets here, it is OK.
The hinge on the elevator side is clamped, positioned to be final drilled. It needs to be positioned carefully to have good alignment before final drill. When positioning the hinge, I connected the hinge to the trim tab for overall alignment
Hinge on the elevato side is drilled and clecoed to elevator rear spar
The edge margin on the fwd hinge (connected to elevator) is much better
Trim tab is clecoed on, the alignment looks good
Gap between trim tab and elevator is acceptable. You can see the bends on both the elevator and trim tab are not perfect, but should not be a concern functional and structural wise. A little filler before painting, nobody will notice this.
Hinge is riveted to trim tab
Shop heads of hinge to trim tab rivets
Trim tab inboard end bends are riveted using pop rivets. The rivet is flush head, but I didn't dimple the bend. So I used a oversized drill bit to countersink the skin. The flush head is very shallow, a standard 100-degree countersink bit will cut too much material. This is a low load area, countersinking should be ok.
Outboard end bend on trim tab is riveted together. The edge margin on the inside bend is very small, I might need to add another smaller rivet between the two. This is also a low load area, the two rivets only hold the bend together, will not transfer any structural load. Maybe two rivets with small edge margin should be ok.
Hinge is riveted to elevator rear spar
Shop heads of hinge to elevator rear spar rivets
Gap between trim tab and elevator after riveting end bends
Alignment after riveting is still good
Left elevator is almost done, just need to bend the leading edge
