Stjohn's RV-7

6 hours.
The fresh air vents take in air from two NACA scoops, one on each side, just forward of the panel. Each one feeds a length of 2″ tubing that ends in an eyeball vent, similar to the ones on commercial airliners, the overhead ones that the inconsiderate nong next to you insists on keeping open and blowing frigid air into your ear while you’re trying to read or sleep. Rather than use the cheap plastic ones from the kit, I opted to spend the cabbage on the nice machined aluminum ones from SteinAir. The SteinAir vents are different in that they mount in a 2″ hole and are held fast by a threaded ring, while the Van’s ones are square and have four AN3 bolt holes designed to grip an angle bracket and a point on the panel. What this means is the mounting needs to be a custom fab, like so:

The next thing to do was dimple the angle for mounting to the side skin. Once that was done, and the part clecoed on, I could match-drill the panel attach hole, then put a nutplate on it. This took lots of measuring, then a bend, then some more measuring, then a few cuts, some drilling, and presto, it’s done.

The second one was easy, all I had to do was make the 90 degree bend at the right distance from the edge of a piece of scrap, then trace the outline from the original part on the opposite side from the bend. Some bandsaw and hole saw work and I got a mirror of the first one. Repeat dimpling/nutplate process.

With the eyeball mounted, it looks pretty sweet.

The only issue here is that the threads on the eyeball don’t go far enough. Minimum thickness this thing can clamp down on is about 3/32″, and my aluminum bracket is maybe half that, so I need to find or make a bushing for the backside so the eyeball can be screwed in tight.
After that, I deburred and dimpled the rest of the subpanel, plus I finished riveting on the weather seal angles. The left-side panel support rib, F-745-L has been truncated at the subpanel to make room for the EFIS. This is a common mod, and the F-745 ribs aren’t structural, so I figured I’d go ahead and do it. If you ask me, putting a panel support rib right down the centerline of the pilot seat is kind of dumb, but I can see where it maximizes efficiency in manufacturing, and it does stiffen the panel. The piece sitting on top of the subpanel in the photo is the aft-of-subpanel piece of the F-745-L rib. I’ll figure out another way to stiffen the panel.

Of course, the skin will have to go back on so I can matchdrill the firewall, as well as the center rib to firewall angle. I wasn’t quite ready to mess with the skin.. That forward top skin is a pain in the butt, so I decided to do something completely different: Start playing with the placement of the throttle quadrant!

The idea is to get the quadrant centered, and I figured I could mock that up by cleco-clamping it to some angle, then try it on for size. It’s easy to reach, doesn’t block the view of anything, and once it’s all bolted in with cables attached, should be solid. Not only that, the aluminum angle strung between the panel and the subpanel for the mount should help stiffen the panel.

This shows the placement relative to the pilot in fore and aft direction.

I have to consult the oracle of VAF to see if I’m even remotely on target with this quadrant thing, But it looks like it should be fine. I’m still avoiding painting the interior, go figure. But there’s plenty to do, like rivet on the firewall recess, fabricate the quadrant mounts, and maybe even do a couple of firewall-mounted items before I need to have a paint day. Then the next discrete step is that engine conversion, which, I gotta tell you, makes me nervous. More on that later.