New Cooling Outlet Skirt

 

When I made the last skirt it I made it with a steeper angle, from the bottom of the cowl.  I decided to make another one to replace it at a shallower, more streamlined, angle to see what happens to the cooling.

It's still the same length, about 3 1/2".  

I riveted it to the front of the short skirt, from a couple versions back, so I had to locate the old rivet holes without taking the cowl off, etc.  Some of the holes were easy to mark from the back side.  I made a card stock pattern of the new skirt until I had a pretty good fit, adding holes as I trimmed it to fit.

Some of these holes were well located, others had to be adjusted to get the pattern properly positioned.  As a result I couldn't easily use them to transfer the locations to the aluminum skirt.  Instead, once I had it Clecoed in the proper position, I drew a circle up close around each Cleco clamp.

I punched a hole at one end of the strip of aluminum, with the Whitney Punch, and used it to Cleco one end of the pattern in place.  Then I punched a hole at the other and Clecoed it, so the pattern wouldn't move.

I used my Optical Center Punch, centered on each circle, to mark the center of each rivet hole.  The Cleco housing is slightly smaller in diameter than the hole in the base of my Grizzy Optical Center Punch.  Looking through the magnifier lens you align the drawn circle with the edge of the hole and mark the center.

How well did it work?  I made the skirt at home and Alodined it, finished, done, took it to the airport and Clecoed it in place.  Every hole fit perfect.  A light clean up of the new 1/8" holes with the #30 drill and all the rivets went right in, not bad.  

Now I just need to go flying.  It was close to dark when I finished.