I've spent gobs of time thinking about switch layouts and drawing out various setups. I finally landed on a design that I think makes logical sense, so I bit the bullet and drilled the holes for the switches. I now have the entire panel cut, with two exceptions: I still need to put a hole in for a keyed switch and I also need to cut the opening for the future IFR GPS.
I wasn't going to use a keyed switch, since most planes that use electronic ignition these days don't bother with them, but I decided that in this day and age of lawsuits, it probably makes sense to put one in as a legal buffer. The key won't control the mags like in a traditional setup. It will simply be in series with the starter button, so the starter can't be engaged without the key. It's completely unnecessary since the master also has to be turned on for the starter to work, but I just shudder to think of my plane sitting on a ramp somewhere and a "the world is all about me" parent letting their kid get into the plane and push buttons. Without a key, the right combo of flipped switches will energize the starter, which can kick over the prop and hurt someone, even though the engine wouldn't likely fire. Of course that would be my fault somehow. So the keyed switch is simply my way of getting a slight edge up on an unscrupulous lawyer.
Here's the layout, pretty much set in stone at this point:
On the left are the engine and avionics related switches (Master, Avionics, Alternator, Pmags and Auto Pilot). I put the AP switch here, because it needs to be turned on before the master is turned on in order to initialize the servos. Above that block of 6 switches is a single toggle for an alternate static source. This will probably be off for the life of the plane, but who knows. It's a toggle with a 1/8 port for the static line from the back of the plane and an opening to cabin air. If the static ports of the plane get plugged, I can flip the switch and change to getting static air pressure from inside the cabin. That obviously throws instruments off a bit in terms of accuracy, but still allows them to function well enough to get the plane on the ground.
Below the engine/power switches are the key switch (still not drilled) and the push button starter. Then below that are the headset jacks. I plan on using a headset with a lemo plug (gets active noise reduction power from the plane vs battery packs), but decided to go ahead and put the lemo jack plus the traditional 2 plug jacks in, just in case I ever switch headsets. The audio panel harness that AFS built came with both setups already wired, so aside from drilling two more holes, it was no more effort to just include them in the panel.
In the center of the panel are the "flight" related switches, grouped by functional use. On the left are the boost pump and flaps, in the middle are lights (navigation, landing, taxi), and on the right are pitot heat and defrost. The defrost is going to control a couple of small computer fans on the glare shield. Defrost is probably the wrong descriptor - it's more like a defog function when sitting on the ground and the humidity is high enough to fog up the canopy before takeoff. In reality, I'll probably have this switch on all of the time, since I think the more useful use of these fans will be to pull hot air from behind the panel to keep the avionics a little cooler.
On the right side of the panel are random things that the pilot won't need access to most of the time. On top is the ELT activation/test panel, then a small push to talk button for passenger use if ever needed (the passenger stick has a PTT button, but I decided not to connect it since I'd rather the stick be removable without having to deal with wire connections). Below that is a 3 port USB charger, then the passenger headset jacks.
