My first exposure to flying was Army helicopter flight school, class 69-13. We were taught to keep our head out of the cockpit, up and looking for other planes in the crowded skies, but at regular intervals to scan the instruments, and we had lots and lots of instruments to scan.
Now I am flying a gyroplane, and the skies aren't as crowded these days, so when I fly, I am looking around as much as possible enjoying the sights the Lord has made, but still looking out for the other guy. I look to my instruments to confirm what I am feeling as to altitude, speed, and direction of travel. And if a "funny" sound comes to my ears I am scanning the engine instruments for a confirmation that all parameters are in the normal.
Last summer I decided to build a Super Bandit and to layout and build the best dang instrument panel I could. The Bandit's designer, Mr. Joe Souza, had selected a sloping fiberglass pod that afforded an aluminum faceplate, the size of which is about 17" by 5.5". Now I had to decide what I wanted my panel to have. I had requested over the Internet, and by writing, 35 catalogs from aviation, auto, electronic, and general metal supply companies to allow me to shop around for the best equipment at the best price. It really amazed me that the same instrument or gauge, even the same brand and EXACT in every detail could cost up to twice as much from catalog to catalog. After reviewing all the catalogs, I selected these instruments from the following places:
2 1/4" airspeed indicator $134.95 Lockwood Aviation Supply
3 1/8" 3-pointer Altimeter $185.00 AirStar Sales
2 1/4" Vertical Speed Ind. $139.00 AirStar Sales
2 1/2" Compass $ 49.00 AirCraft Spruce
2 1/4" Slip Indicator $ 32.95 Leading Edge Air Foil
2" Tiny-Tach $ 47.00 AirStar Sales
2 1/4" Digital Oil Press $ 29.95 Summit (Intellitronix Corp.)
Oil Sender unit $ 19.25 Summit (Intellitronix Corp.)
2 1/4" Digital Water Temp $ 29.95 Summit (Intellitronix Corp.)
Water Temp Sender $ 15.95 Summit (Intellitronix Corp.)
Rotor Tach (bike comp) $ 14.95 Harbor Freight
Volt meter/Clock $ 19.95 J.C. Whitney
Air Temp In/Out $ 15.95 Radio Shack
Fuse holders (5) $ 12.50 Digi-Key
Ferrite Beads, Caps $ 9.50 Digi-Key
Switches (1 main, 4 med) $ 12.00 JAMECO
Assorted Shielded cable $ 22.00 All Electronics
I chose most of the instruments and gauges of the 2" and 2 -1/4" size to save on space, but just because a gauge is advertised as 2 -1/4" does not mean that the body of it (behind the panel) can't be much larger. Also some of the instruments might be deep such as the altimeter at over 7".
I use AutoCAD to do mechanical drawings at work. After getting all the instruments and gauges, I measured the actual size of them and the size panel cutout each required and made a precise 1:1 scale drawing of each. If you don’t have a CAD program, you can do the same thing by using 3x5 cards and cutting them out in the shapes of the instruments (hint, put a pin hole in the center of the mounting holes and in the center of the panel cutout, as it might not be the center of the instrument) The next step is to figure out where each instrument should go. AirCraft Spruce has several good examples of functional layouts in their instrument section.
I chose a straightforward logical layout. I placed the compass in the top center and the airspeed indicator centered just below it. To the right, I placed the altimeter and then the VSI so that all my "air" instruments are clustered together. Above these, I placed my engine tach and my rotor tach side by side. Because my rotor tach (bike computer) is surface mounted, I had room underneath it to mount a slip indicator which has a rather large solid body behind the panel. On the far right, I made a bracket to hold my ICOM radio. Below it is a hot, fused, power switch wired thru some caps and ferrite beads, to aid in noise suppression, to three power outlets for the radio, my GPS, and a spare.
On the bottom, to the left of the air speed indicator I place the digital oil pressure indicator, then the three lighting switches (strobe, landing, instrument) and their fuses followed by the digital water temp gauge. I originally had normal needle gauges but wanted the more precise, easy to read, digital engine gauges. Above these, I placed the digital clock/stopwatch/volt meter and the digital air temp gauge. The temp gauge also has an "external" temp probe on a ten-foot wire that I epoxied to the surface of my intake manifold directly under the carburetor to monitor for carb ice. And the Master Power and ignition switch in the top left.
Using my CAD program, I moved the instruments and gauges around to try and give them as much room as possible from each other. Then I printed out on our "B" size printer at work, a 1:1 (life size) drawing of the gauge locations each with a small x's in the center of the instruments and centers of their mounting holes.
Here is a $5.00 trick to save you costly headaches. I next went to the local metal supply and bought a sheet of .020" thick aluminum about the same size as the front panel. I then taped the 1:1 of the panel to it, used a center punch on all the x's and cut and drilled this thin sheet like it was the real panel to fit check everything. Yes it took an exrtra Saturday but I found I had to move the Compass down because it was so deep the sloping of the pod would not allow it to fit (remember you are dealing in three dimensions, not two) so it was worth the time and $5.00 not screw up the good panel plate. (it is also good for testing paint)
A cost saving note on the circular hole-cutting tool used for instruments and gauges. It is listed in the AirCraft Spruce catalog on page 452, #12-10600 for $8.95. I have seen this exact same tool in other catalogs for up to $39.00 ! It works great on .050" aluminum if you follow two simple rules. Using protective pieces of wood or old pieces of tupperware, clamp the plate you are drilling down very, very firmly, and lower the hole cutter with your drill press very, very slowly.
A few other suggestions: Use your sample panel to test if any of the instruments or gauges interfere magnetically with the compass. Don't use steel for a front panel; it breeds rust and corrosion, and it will become magnetized, throwing off your compass no matter where you mount it. Likewise don't use steel screws and nuts for mounting hardware; use brass screws and nuts. To make sure that they are really brass, try "picking them up" with a magnet. Real brass has no attraction to a magnet. On the back side of all your mounting screws, after you tighten the nuts, coat the exposed threads with a hot glue gun. The nuts won't vibrate loose, and it can be pealed off with tweezers if you do need to remove a gauge. Use tie-wraps, waxed lacing cord, or even dental floss to bundle all the wires and hoses behind the panel tight, so that they don't rub, chafe, or flex.
I am very happy and proud of the way my instrument panel came out. If you take your time, you too will feel proud every time you look at yours, and maybe it will cause you to remember to look at your instruments more often. Enjoy your view.
You can see the whole story of my Bandit build, as
well as this story, with Internet jumps to all the suppliers listed, at:
http://home.pacbell.net/tsled