Panel Design
This shows the finished panel layout.
Flight instruments are from left to right, ASI, Alti, Compass, VSI. Lower center is the EIS, with a Garmin GPS III+ to the right of that. On the keel is the radio, and under the keel is the control box for the strobe.
Switches from left to right are spare, aux socket (car cigar socket top right), GPS, intercom/radio, EIS, strobe. All switches have a fuse above, except the strobe whose fuse is in the control box. The fuse just below the cigar socket is for the RPM. In case you wonder I'm not a heavy smoker! The cigar adapter is for camera/phone charging etc.
The knob lower left is for the volume control of the audio alarm output of the EIS which is fed into the Lynx power adapter under the seat, fixed to the trailing link.
You can just see the PTT switch for the radio on the passenger foot bar which also shows the heatshrink protection from passenger feet. I keep it here when not rigged, and attach it to the control bar when rigged. The keel in front of the seat also has prop tape on it to protect against scuffs when getting in and out.
I started the panel layout by using a blank picture of the panel and then moving bitmaps of the main instruments around until I was happy. You can see those thought processes here.
Once the layout had been done it was time to transfer this to the actual panel. I found the easiest way was to construct to datum lines from which everything else was measured. A center line from strut down vertically was a natural one, and then one along the lower edge of the panel to provide a horizontal datum.
The first cut is the hardest. Make sure it is right! I think I
used a 3 1/8" hole saw for all the main instrument holes and then fettling
from there to get a nice snug fit. The compass hole, which was the first had
drifted to the left as I was drilling the pilot hole, and I hadn't
noticed
it! Arghhhh! Well fortunately the 2mm drift to the left was recoverable as the
hole was fettled to the right using abrasive paper to get the compass to fit
snugly. Phew! Won't do that again.
Then came the VSI and Alti, both of which have a D cut out to take the adjuster. This required making a template of the extra cutout and using a fine file etc to work a close fit, with constant in/out of the instrument until a nice fit was achieved. The ASI was a "simple" hole by comparison! I left the EIS hole until last of the main holes as I knew that the panel would be weakened by the material removal. The aluminium panel of the EIS would more than make up for the loss of material.
There is a hole either side of the strut for the alarm indicators of the EIS. The small hole top right is for a splash proof car cigar type socket for anything I have forgotten like a camera, phone charger etc.
This is a picture of the loaded panel. It looks decidedly distorted, but
that's an aberration of the angle I took the picture at with the camera and is
perfectly symmetrical in reality! The master key switch is shown lower right. A mistake here meant I placed it too close to the side of the pod and the
throttle cable wouldn't tuck up nicely between the key switch and the pod behind
the panel. Could have done better!
Fasteners are all stainless steel. The round black object to the right of the EIS is the base mount for a Garmin GPS III swivel mount. I spent a lot of time deciding on a suitable GPS position that would be easily visible, not effecting the compass, and able to be horizontal or vertical orientated. My preference is for horizontal, but you takes your pick! I found that if a component can effect the compass then by placing it lower that the compass plane the effect is greatly minimised. The batteries if left in the GPS do have a small effect, but then I never put them in! This picture also clearly shows the switches, mostly with fuses above. The swiches are 15A SPST, with waterproof rubber covers. The fuse holders are for 20mm fuses, with a hand turn top. The EIS was sealed with silicone and a thin smear was used to provide a panel barrier gasket as well.
A neat trick from a friend whose garage I took over for the build was to use the switch and fuse covers with some blue tack underneath and play around with their location until happy. I think this took a couple of hours, with canvassing opinion from all. Why so many switches? Well I decided that I wanted to be able to fully isolate every electrical sub system if I had to and it just looked the part!