The last couple of evening I’ve been using trial and error to work out the right structure to support the wiring behind the sub panel.
One of the changes I’ve made is to rivet together two pieces of channel to reduce the sharp edges.
I also installed an adel clamp bracket on the right side of the subpanel to hold several wiring bundles.
Tonight I started on the daunting task of trying to tidy up the wiring under and behind the panel. It’s a giant, heavy, ball of spaghetti right now, and I’m not sure if I have enough length to position things where I need them.
I decided I needed some kind of frame behind the subpanel to support the main wiring harness. Using some spare channel, I mocked up a frame and started trying to figure out a solution. I eventually settled on two channels running from the sub panel to the firewall, and a cross beam made from another length of channel. I should be able to rivet the fore/aft channels on the sub-panel end, but not sure I’ll be able to get rivets in on the firewall end.
Today I installed the FlyLED controller board and the light dimmer circuit board. These both went of the forward side of the sub panel. The mounting hardware protrudes through the sub panel, behind the vpower unit.
I uninstalled the shelf that holds the vpower box and transponder, to allow access to drill the mounting holes for both boards.
Dad made a template to mark the holes, and then we drilled them to the correct size. The plastic standoff pins for the FlyLED board worked nicely, the only tricky part was mounting the board, which I did by feel, since there’s no easy access.
After some time off building for work and other events, I was able to get some time in the garage today. I made a cover for the fuse box, as I won’t be using it. It’s also a (hopefully) convenient location to mount the CO detector. I found a template on Vans Air Force, cut it out, drill holes, and countersunk for flush screws. I match drilled holes for the CO detector mount, then primed the cover.
I also rebuilt the bottom shelf on the pilot side, making a much stronger version. I have been iterating on the design several times, but think I have it right this time. I did a test fit with the vertical power unit and the transponder, and it looks good to me.
The last two days I’ve been working on the passenger side shelves for the engine monitor, air data computer, and the satellite receiver.
Tonight I decided where to install the standby battery and made the parts to mount it above the center channel about 3 inches aft of the firewall on the cover panel between the sets of rudder pedals. I made backing plates to reinforce the panel and to hold the nut plates.
It was a pain to work on this panel because the canopy release cable passes through behind the battery, and I can’t remove the panel without undoing work on the canopy release mechanism. So I drilled, deburred and riveted everything with the panel nearly in place, which was awkward.
Over the last couple of days I’ve been slowly refining the design and construction for the sub panel mounts on the pilot side. The two biggest boxes going in this area are the Vertical Power and Transponder unit. Originally I was planning to orient these horizontally, but when I installed the bank of switches, there isn’t enough room. So I switched the orientation to vertical. This also meant the standby battery wouldn’t fit, so that is going to move somewhere else. Tonight I finished the construction and test fit everything.
Tonight I worked on making the first mount for the sub-panel. This will house the GTR-20 remote com radio, and the GMA-245R remote audio panel.
Since my last blog post I’ve made multiple revisions to my plans for mounting the hardware. I’m reasonably happy with the final arrangement, and it’s good enough to get started building. I’m sure I’ll decide to change something else, but it’s time to get started making stuff.
Everything went according to plan, and it turned out alright. With no pre-punched or pre-formed parts the whole construction process took a lot longer.
Tonight I worked out how I plan to mount the GEA24 box. This will mount directly onto the sub panel, with a doubler on each side to support the nut plates and provide some additional strength. The box itself is not heavy, but with the cables attached it will be heavier. It also needs to be able to withstand repeated +6/-3 G loads without cracking, so I want the mount to be strong.
Space on the forward side of the sub-panel is tight on one side, and open on the other. I made up to backing plates, the drilled, countersunk, and primed them.
Tonight I came up with what I believe will be the right placement for the remote components behind the panel. Initially, it looks like everything will fit in with room to install all the necessary wiring harnesses and d-sub connectors. On the left side, I need to determine the orientation of the boxes. I think setting the vertical power and transponder vertically against the sub-panel, with the standby battery sitting on a tray at the bottom of the space will result in the best clearance. However I’ll keep options open and try both.
Now I need to work out the tray structure I need to build to hold these components. I’ve seen a few ideas, but need to settle on a plan.
