The user interface for your aircraft. Great airplanes make the controls disappear. You fuse with the airframe feeling the landing gear as an extension of your feet and the wingtips like fingers brushing through the airstream. With practice, humans are quite adept at integrating their sense of self with external technology. This kind of symbiosis tends to come with mastery, but we're all too aware of how clunky user interfaces can frustrate this seamless connection. ![[Instrument Panel-20241228152543716.webp]] Operating under this basic assumption I allowed myself to spend a bit of extra time to design a panel that will hopefully feel like second nature quickly. For better or worse the decision tree collapsed pretty quickly based on my preferences, the limited space of the fuselage, and other constraints. ![[Instrument Panel-20241228152554988.webp]] Even though I like traditional instruments, I decided to go with a glass panel for a few reasons. They act like annunciators. Instead of having to constantly scan the instruments for non-standard operating parameters they do this for the pilot and throw warnings when some sensor input is out of range. With traditional instruments this is also possible but adds a lot of complexity to the installation. The other reason is autopilot-based navigation. Being able to sync a flight plan and have the airplane fly a multi-leg track can be very useful in some circumstance. This can make VFR flying in the complex European airspace a lot more relaxed. It reduces the number of constant cross checks and frees resources for working the radio or looking out for traffic. Also see → [[Avionics and Electrical Overview]] ![[Instrument Panel-20241228152607669.webp]] When it comes to glass panels they are a bit like mobile operating systems. Some like iOS others Android. I have a preference for Garmin because I find their UI cleaner and more to the point. Good installation documentation was also an important factor when choosing the system. The G3X docs are great. Anybody who has the endurance to plough through the 1000-page PDF will be rewarded with a lot of confidence in installing advanced avionics. Unfortunately, the stock panel does not provide enough space for the GSU 460 display. The good news is that building a new panel allowed for a very central piece of the airplane to be optimally modified and customized. At least this is how I convinced myself to invest the extra time. ![[Instrument Panel-20241228152620816.webp]] The fix was easy, increase the vertical panel real estate. For ergonomics I also opted to increase the panel slant a bit. ![[Instrument Panel-20241228152631639.webp]] I cannot stress enough how important it is to verify the space requirements behind the panel. Even though I must have spent hours doing this I had some close calls. It is very easy to miss possible interference with the fuselage tubes, especially when increasing the slant. ![[Instrument Panel-20241228152642306.webp]] Building molds for composite parts can be very time consuming. My goal was to leverage my fine box cutter skills to make a quick layup on a foam core. ![[Instrument Panel-20241228152652309.webp]] ![[Instrument Panel-20241228152703423.webp]] <iframe src="https://www.youtube.com/embed/X3CNdPoJOGg?si=bqeJBHv8BFxBa5ld" frameborder="0" allowfullscreen style="width: 100%; aspect-ratio: 16/9;"></iframe> Working with composites is time-consuming, yet it is also forgiving. Take, for instance, the time when I didn't quite achieve the correct slant angle—I simply incorporated the necessary wedge by pouring in some micro-balloon epoxy. ![[Instrument Panel-20241228152714886.webp]] "Simple changes" have a tendency to percolate, with airplanes. Correcting the angle at the bottom required a correction at the top. Custom washers did the trick. ![[Instrument Panel-20241228152723667.webp]] ![[Instrument Panel-20241228152733038.webp]] The exact layout placement is anchored to the center display and the engine controls. Latter have to clear the fuselage tube in the back. From there I indexed the rest. ![[Instrument Panel-20241228152746200.webp]] Generally speaking a lot of moving targets started to emerge in this phase of the build. Many of the panel control placements depend on the firewall layout. Where are the primer lines routed? Where should the cabin and carb heat controls penetrate the firewall? I decided to switch gears and do the firewall layout first and then work myself back to the panel from there. There is a lot to keep in your head at the same time. At times I wished I had chosen a kit that was more opinionated about the firewall forward components. On the other hand the satisfaction of solving all these challenges is very rewarding, addicting even. Who doesn’t like a good riddle? ![[Instrument Panel-20241228152757262.webp]] After about five panel layout iterations, I committed. At this point, I had done so much manual precision cutting that I felt confident I could do it by hand. My process is to draw the cutlines on tape. Then, I cut along these lines with a box cutter and remove the tape exactly where the material should be removed. Finally, I cut to about 1mm, of the blue tape edge and sand the rest. ![[Instrument Panel-20241228152806901.webp]] For the 57mm round gauges, I used a large step drill, then an end mill on a Dremel to cut close to the tape edge, and finally just various grits of sandpaper. This made it quite easy to get a perfect friction fit. ![[Instrument Panel-20241228152814525.webp]] The final step is about refining the surface. This is basically just a matter of sanding it smooth (100 and 320 grit) and spraying two to three layers of clear coat from a spray can. I got the best results with matte clear coat (2K). Sanding usually exposes low points. These can be filled in by brushing on some epoxy. Sometimes multiple iterations of sanding and brushing are necessary. This iterative process avoids having to sand off more than the first layer of fibers. In the end, this is a tradeoff between the number of iterations and how much material to sand off. ![[Instrument Panel-20241228152823757.webp]] ![[Instrument Panel-20241228152837653.webp]] ![[Instrument Panel-20241228152847228.webp]] ![[Instrument Panel-20241228152856600.webp]] ![[Instrument Panel-20241228152905726.webp]] Comparing the design files with the final product is always interesting. It was not a 1:1 translation. Rather, I caught some problems along the way which had me move the prop control over a bit. I also needed to swap the BAT breaker with the wing tip landing light control dial. Finally I had to rotate the GMC and RDO breakers to increase the clearance in the back. ![[Instrument Panel-20241228152928245.webp]] Getting hands-on with the panel is the ultimate test—it highlights what works and what doesn't. I have to say, it feels quite natural. The way it allows you to index your fingers on either the bottom ledge or the top edge for all of the controls is particularly nice. Can’t wait to fly it! ![[Instrument Panel-20241228152938366.webp]]