Avionics Stack Cut-Out
Hi Russel,
By using/measuring several typical trays (Garmin, ICOM, PS Engineering), I came up with a panel cut-out width of 6.1875 inch (6-3/16) and 6.3125 (6-5/16) between the mounting angles behind the panel. The 6.1875 panel cut-out allows for the trays to be mounted behind the Vans .063-inch thick instrument panel. I tried fitting the transponder, radio, etc., with this configuration and they slid-in and locked fine with some depth to spare between the back of the avionics bezel and the panel.
As John says, the standard panel cut-out width is 6.250, and the trays are mounted flush with the front of the instrument panel instead of behind it. I wanted my trays behind the panel so that the cut-out could not be easily seen behind the avionics front face bezels. Note: I don?t know if you can mount the trays behind a thicker instrument panel (.090, for example, ala Affordable Panels) and still slide-in the avionics and lock them.
As far as the tray mounting angles are concerned, it appears that they must be at least 6.300 inches apart so that any typical tray can fit between them. (The ICOM tray was slightly wider than the Garmin and PS Engineering ones.) I installed my angles 6.3125 inches apart figuring I can always shim the trays to center them.
As far as the height is concerned, it?s a good idea to add between .032 and .063 between each avionic component in order to promote some air circulation between them. This is usually done by stacking the trays with spacers. Then measure the total stacked tray height and cut.
Note: For the panel cut-out, you can always go narrower/lower and widen later. It?s more difficult to start wider and narrow later! The space between the mounting angles needs to be decided up-front, though.
Good Luck!
Bill Palmer
