Mounting avionics stack
I started looking more seriously at how to mount the avionics to the panel. The cutout Ross made in the panel is 6.25″ wide. The bezels on most of the avionics are 6.30″. The exceptions are the PMA 8000B audio panel which seems to be 6.33″ and the SL-40 radio which is about 6.27″. Also, the SL-40 does not leave a gap between the bezel and tray. The cutout must be at least 6.27″ wide for it to fit. So I spent the better part of an hour filing the edges of the avionics cut out. I’d like to actually have only half of the bezel stick out, but I’d have to make the whole cutout 6.33″ to fit the audio panel. That would leave a bit of a gap around all the other avionics.
The PMA tray is strange. Instead of securing the instrument via a cam at the bottom front like the Garmin units, it uses a weird screw/nutplate arrangement at the back. That would be fine except the tray is pretty loose at the front. I’m going to have to stick some UHMW tape in there or something to keep it from flopping around. (Edit 9/14/06: Mark from PS Engineering contacted me. Since the PMA8000B is plug and play replaceable with the GMA340, they have the exact same mount. I don’t have any doubt that the mount will be secure once everything is permanently installed. It’s just odd that Garmin hasn’t tried to standardize their equipment over time. I guess it’s an artifact of them buying up other products.)
I propped up the avionics at the back and did a dry fit in the panel. Looks like there’s a bit of a gap top to bottom. I’ll try to put most of that at the bottom where it’s less visible. I installed a couple switches under the avionics to make sure they were still accessible–no problem.
I cut a couple of lengths of 3/4″x3/4″x.063 angle to the height of the opening plus 1/4″. Now I just need to figure out how to hold the avionics in place so I can drill them to the panel. Mounting the trays to the panel is definitely not a plug-and-play process.