<July 31, 2005>
Still More Rudder - Deburr, Dimple and Countersink
Will this rudder ever end?!?! 8^) I started the day by deburring and dimpling the second rudder skin, then I completed the edge-finishing on both. After than I went right into countersinking several of the parts. I finished the day with a soapy scotchbrite scrubdown of all the parts, then hung them up to dry. I will etch and prime all the parts tomorrow in preparation for assembly.
Here is the R-912 Counterbalance Rib after match drilling to the Counterbalance Weight. Since I didn't have a #10 dimple die, I invented my own method. First I dimpled the hole with a #8 dimple die (I did have that one), then I drilled a piece of scrap wood with the appropriate size hole, and I used my #10 countersink to make what would effectively be a female dimple die. I then inserted a #10 screw into the hole, though the rib and then the wood die, and capped it off with a washer and nut. I took a wrench and tightened the nut the point where the screw head sat flush with the rib. This method seemed to have worked well for me.
I countersunk the R-916 (AEX) Rudder Wedge. I did this by first clamping it to the edge of a piece of scrap wood, match-drilling each hole in the wedge into the wood, and inserting clecos every so often. The holes were drilled into the wood to accept the pilot of the countersinking bit.
Countersinking the Rudder Wedge was a piece of cake using this method. You can see that if you didn't have the wedge at the edge of the table (wood) the countersink cage would hit the table.
All done! The second side was even easier as the holes were already drilled into the wood. All I had to do was use a couple of clecos to hold the wedge still while I countersunk. The entire process took me about 30 minutes and was much easier than I thought it would be.