RV-14 Question On Horizontal Stab Skin

This evening while dimpling the skins to my horizontal stab I noticed that the dimples were flat, well formed, but just didn't look like the other skins I'd done. I stopped about half way though and stuck a 426-3 rivet into one of the undimpled holes...it wouldn't fit.

I went back and looked at the manual for quite some time before determining that nowhere does it say to final-drill the skins out to #40 on the stab. We were told to Final-Drill the vertical stab in step 1 page 06-04. The rudder had us match drill a few of the holes, but none in the field of the rudder.

On the rudder, drilling was not necessary...but a 426-3 rivet would fit into the pre-punched holes in the rudder.

I'm using Cleaveland dies and the male has no problem fitting into the pre-punced hole. After the hole is dimpled, a 426-3 has no problem fitting....and no, I'm not underdimpling.

So here's the question, for those of you building the -14...did you predrill the prepunched holes in the stab?

Thanks,

Fred

Reflex said:

So here's the question, for those of you building the -14...did you predrill the prepunched holes in the stab?

Click to expand...

On the skins - not required.
On the ribs - required because they are actually RV-10 parts (reference the part #'s)

Scott,

Many thanks for the reply. I figured that it's possible to do, but it would require a step calling for placement of the stab skins in the jigs and placing the stab skeleton in the skins and held in place by clecos followed by match drilling.

Just thought it odd that a -3 rivet wouldn't fit in the holes. Perhaps it's just a little primer keeping them from fitting.

Thanks again,

Fred

You'll run into a bunch of similar situations as you progress ..

I just follow the directions as best they are written and then just determine based on how the hole looks (does it need deburred?) and how rivets fit (Does it need match drilled?).

I'm on the elevators now .. the instructions are great but there are situations where you may have to use the experience you've built up on the previous assemblies to make a determination.

Really just keep in mind the reasons for dimpling and deburring .. aesthetics and preventing shearing (dimples wearing and falling out).

If you have to jam a rivet in then go ahead and match drill it again, things shift slightly sometimes, inspect for burrs, repeat, etc.

Edit: unrelated but since you're just getting started this may help .. that rivet gun with the anvil can do some cosmetic damage to the skins (burnishing?) .. I simply had to get over it and keep in mind the painter can fix just about anything, including smileys. I think I'm up to around 4 smileys so far, I just put a yellow "smiley" sticker over them and move on.