Because the stabilator assembly is about to get really big really soon, I thought it prudent to dimple the ribs prior to assembly. That said, no work was continued on the spar box assembly except for dimpling the four small ribs already attached to the forward spar.
Prior to dimpling all the ribs an inspection was made to make
sure the outer skin would sit flat on the ribs. There were a few places where the fluting
caused small bulges where the skin would lay so the ribs were all checked and
tweaked as necessary with a small pair of flat nose pliers.
The dimpling was done with the pneumatic
squeezer with the small custom made female die on the inside of the flange as
to not mar the metal at the bend where the rib flange transitions to become the
rib’s web. Also of note, with the exception of the far outboard ribs, all of the
ribs have lightening holes that are raised from the web … this interferes with
the yoke on the squeezer preventing it from being square to the flange at various
locations on each type of rib. All the
holes that had good access were dimpled with the pneumatic squeezer the remainder were dimpled
with the custom dimple dies that are to be used with a hand pop riveting tool.
Dimpling the stabilator’s ribs using the
pneumatic squeezer and 120 degree dies.
Dimpling the problem holes with the hand pop
rivet tool and the custom 120 degree
dimple dies with the hole in them for a
nail to be inserted into the pop rivet tool.