Cutting the panel | 1.23.2021 - 1.24.2021

My weekend project was to get the panel to the 99% mark for installation of avionics. Largely, I succeeded. There's only two more holes to drill, both of which I don't know the diameter of, because they're the only two switches that I don't have on hand.

On Saturday, I worked on locating and drilling the hole for the avionics stack and installing the front avionics rails. Our avionics stack currently consists of a GMC 507 autopilot control, GMA 245 audio panel, and GPS 175 navigator. Eventually, there will probably be a traditional second nav/com below these (GNC 255), but for now we're slumming it with a single radio and only GPS navigation. The radio will likely be installed within the next year, but we're holding off for now.

This hole was pretty simple to locate and cut. Every cut on this panel started undersized, because I only get one real shot at this, so I'd rather cut more out later than cut too much to begin with. I'd then either trim more off, or file the rest off.

Biggest tip: DO NOT cut the panel to the specs listed in the various avionics manuals. They all want it cut much bigger than it needs to be. Had I cut to this spec without checking everything with the avionics in the rack, I would have ended up with gaps to the side of the avionics, which I didn't want for a clean looking panel.

Hole cut and avionics racks getting test fit

Once the racks and devices were test fit, I sanded the back of the panel and attached 1/2" x 3/4" angle aluminum strips with the 3/4" side against the racks to form the front rails. This was left to cure overnight.

Here it is the next evening.

Note that the topmost portion of the hole doesn't have rails. That's where the GMC 507 is going, and it's typically just surface mounted to the panel.

On Sunday, I started working on cutting everything else out. This took *way* longer than I was expecting, and I spent ~6.5 hours triple-checking everything and then cutting the holes. Those AML 34 switch holes were particularly troublesome, since there's not much wiggle room from "too small" to "too big". Every one of them was hand finished with a file. I think I have 3 hours into getting the layout just right and cutting the holes. On 6 switches. Yikes.

Printed template taped on

I started with a scale printed hole template that was taped on, but then I realized after one hole that I had printable label paper. Printed on that and then adhered that on. Worked way better.

Each hole was finish filed until it was *just* big enough to get a switch into.

Cuts all done. I kind of messed up the rightmost one, but the switch bezel barely covers it and it's not as bad in person as it looks in this picture. Maybe 1/32" oops. Just for scale on how sensitive the size is.

Once the switches were done, I cut everything else out using various hole saws, templates, drills, and the jigsaw.

Almost everything cut out, MFD needs the edges trimmed more here.

And here's the final product installed in the plane:

Yes, I do see the irony in paying good money for a big sheet of fiberglass and then cutting nearly all of it out.

And just because Emily and I couldn't resist...

This whole project is starting to feel *very* real.

That's it for the weekend!
- Jeff