I did a bit of wiring cleanup this weekend, did some prep work on the upper forward fuselage skin and spent a lot of time pondering the control linkage for the oil cooler door.

I'm slowly getting to the stage where I will be able to rivet the upper forward fuselage skin. I countersunk most of the holes where the lower edge of that skin overlays the upper longeron. There are eight rivets on each side that have very, very poor access due to the top of the landing gear boxes. A few brave builders manufacture special bucking bars to get at those rivets, but I've got so much stuff going through the landing gear boxes that I will do what most builders do - use blind rivets. The rivet of choice seems to be the CherryMax CR3212-4-4. Some builders (e.g. Larry Bowen) have used the CR3214-4-4, which has a smaller head, but I'm not happy with putting eight of those in a row, as the small head and big diameter of those rivets wouldn't produce as much "pull" strength as the solid rivets that the plans call for.

I drilled the holes for the CherryMax blind rivets out to 1/8 inch (the solid rivets used everywhere else on this skin are 3/32 inch diameter). I countersunk the 3/32 holes, and deburred and dimpled some of the holes on the skin (I only did the ones that needed the C-Frame dimpler and hammer, as that makes too much noise to do early in the morning, when Terry is still asleep).

One of the last big tasks I need to do before riveting this skin is to fabricate and install the control for my oil cooler air door. I built the sliding door a long time ago, but I never sorted out the control linkage. I had a couple of big-picture concepts, but they fell apart once I started pondering the intricate details. I spent quite a while sketching various concepts, cutting up cardboard to try mockups, and think I finally have a workable concept. One of the hardest parts was figuring out exactly which Bowden cable to order - there are so many different types, each with its own peculiarities. I don't have a lot of room to work with, so I needed to consider exactly how each type of Bowden cable would be secured, and how it would attach to the linkage before I could come to a decision. Anyway, I ordered a cable and all the attachment hardware. We'll see in a few weeks whether this plan will do the job.

I also painted the brackets for the heater box control, so I can install them later this week.