We've been doing the annual on our group's Cherokee, which unfortunately ran into a couple of major snags we hadn't expected. Ended up spending most of the last couple of weeks working on that instead of my project. Can't complain.
We do owner assisted annuals, and I've learned so much from Nick (whose Dad was an A&P) and our A&P that it's well worth the time spent. I always learn something new and nearly always get to work on something I'm about to do or need to do on my own project.
I was able to finish up the radio stack. I included more pictures of what I did. I can't claim it's the best way, but it did work pretty well. When I went looking to see what other folks had done I didn't find much but some taped together mockups and what it looked like from the front when it was done. Not a lot of help in other words. FWIW, this is what I did.
I cut out the hole in the sub panel with a jig saw. It has a fine blade and did a pretty good job, but once a fair amount of the material was cut I had to support the heck out of it to keep it from jumping all over the place. Then a mill bastard file did the rest. I used blue tape as a "cut to" line to make sure I'd removed enough material.
BTW - I arrived at this shape by using a couple of different squares to project the front opening to the rear - it's not really a straight line, so you can't lay them on top of each other (at least i couldn't figure out a reliable way to).
It worked out really well and the opening was almost exactly the right size, and is within 1/8" all around, which works for me.
I removed the ribs and center section so I could do the test fitting and filing on my workbench.
I wasn't sure how deep the trays needed to be mounted so the faceplate would fit flush with the panel, so I did quite a bit of tweaking on each tray to make sure it all fit. The only real gotcha was my SL40 was a bit rough along the sides, so I had to file a bit deeper groove. Bill at Up North had the groove perfectly placed and the depth would have been correct but for the side tabs being a bit rough.
The rest was just putting each in place, measuring a bunch of times, clamping it tightly, then marking the side angles for drilling.
I would mark it, then remove the angle, drill and bolt it in. I mostly used #6 flush head screws, but my Icom worked better with #8, so I used those on the A210 tray.
GPS 400 tray fits great. Rinse and repeat.
This is everything in place, but the rails not yet drilled to the front panel.
Back side view. I want everything to be removable so I can swap stuff out if I need to, plus it will leave a nice hole if I need to get behind the panel to work on wiring. The entire panel will be removable as well for good access.
Last setup before I mark and back drill the angle to the front panel.
Nut plates mounted (these are #6 as well) and drilled to the front panel.
I planned for a pretty snug fit in the sub panel. I don't want the stack bouncing around in turbulence. I originally thought to put an angle support below, but decided to mount about a long piece of angle and attach to the two aft holes on the GPS 400 mount. The rest fits snugly enough it won't move. I also plan to use edge grommet or some other anti chafe material around the periphery of the sub panel cutout.
Test fit in the aircraft.
All the avionics installed and snugged up. Very happy with how it came out.
Starting on the map box from Van's.
Finished riveting. I used flush rivets all around for a smooth finish inside. I just back riveted everything.
Test fit in the sub panel. I had Bill cut the panel based on the CD plans I got from Van's, and the dimensions were bang on. I think I will make it removable as well - #6 nutplates on the front flange.
I'd like to find a flush latch, but haven't found anything I like yet. I should have had Bill relieve the bottom side of the cutout for the hinge. I originally planned to put it inside but should have realized that wouldn't work. Had to spend about an hour filing the lower edge down to get a good fit for the piano hinge. Hinge will be flush riveted as well.
Next project was to find a home for the VPX. I probably spent a couple of hours trying various things before I settled on mounting it upside down below the two left side forward ribs behind the sub panel. I used some of the extra angle I got with the wing kit to fab a couple of rails. Everything will get nutplates so it's easily removable.
Top view. There is enough room to put something above or behind the sub panel. I don't plan to put anything above but definitely plan to use the back side of the sub panel.
Lower view. Most of the power will be doing either forward and down or to the right, so the large power on the right side will work well. If not, it's easily reversed because all the holes are symmetrical.
