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Subpanel Mental Block Help

J

jchang10

Well Known Member
Builders, I need some help getting over this major mental block that I seem to have regarding mounting the various misc subpanel black boxes like: manifold pressure sensor, fuse blocks, lightspeed module (future), and engine monitoring box, etc.

Because the entire subpanel structure is riveted in place and will basically never ever get replaced easily due to being riveted in and the windshield right above, I am having a hard timing just drilling mount holes in fwd fuse ribs and such to mount black boxes directly. I keep wanting to come up with a better method for future access, as well as changes. Maybe use a platform sistered to a rib with standoffs? Maybe use standoffs instead of just mounting direct to rib?

On the other hand, this is my 5th year, so once again, I feel like I am needlessly prolonging the build by debating over these "mundane" issues for most others.

I am writing, because maybe all I need is a pat on the back and a kick in the butt to just do it? IE just go ahead and mount everything directly. Odds are, you will never ever see these areas again. PS. Yes, I have been told i have commitment issues.

Thanks for any insights!
Jae

Capture.JPG
 
My main panel is in 3 pieces, and the two on the sides are arranged to lay flat for service. This allows access to the sub panel items also.

I had posted photos on the sticky about panels, but the photo hosting site is TU.

I will get more shots up here in a while.

To do what I did, you have to have all the wiring go towards the bottom edge of the panel, and have enough slack to pull the panel section out a couple inches, then lay it down.

Good luck,
 
I didn't do anything special here. I figure removing the EFIS screens and 696 mount will create enough "holes" to work through that I won't need to remove the panel to work on the subpanel in the future.

-Rob
 
RV10Rob said:
I didn't do anything special here. I figure removing the EFIS screens and 696 mount will create enough "holes" to work through that I won't need to remove the panel to work on the subpanel in the future.
Click to expand...
I also am using this method. I have two 8.5" GRT displays, a Garmin 695, an avionics stack. These instruments all have large rectangular openings. The wiring is very accessible from underneath the main panel. If I ever have to get back to the subpanel I can take out any one, or multiple instruments to get to the subpanel. I did mount a "shelf" behind the subpanel, secured to the firewall and the back of the subpanel for my AHRS unit. I did cut a whole in the subpanel for access to this shelf. However, if you do not need behind the subpanel then the instrument holes should provide adequate access to anything on the subpanel.

Of course, all of this discussion is due to the flat panel instruments I have installed. If you are using round gauges YMMV.
 
Subpanel mounts

I'd like to throw my opinion in for the subpanel mounts as well. I have a dual GRT, EIS, and full avionics stack. I am having no problems with access to the subpanel components with the screens removed and under the panel. If I need to ever get back to them I just pull the seat and a control stick and I can lay on my back and reach everything.

Eric Kallio
 
So then did you start mounting black boxes on the aft facing sub panel first? It sounds like most have not had to mount anything forward of the sub panel then?

I was actually going to start mounting some things like the "manifold pressure sensor" on the forward part of subpanel, then work aft, thus, installing things in hard to reach areas first.
 
The manifold sensor has a tubing connecting to it. I found it easier to mount that sensor in the engine compartment and run the wires out through the firewall. This is with Dynon equipment your may vary.
 
subpanel layout

I have all of my grounding tabs, terminal and fuse blocks, and avionics contactors on the firewall. A bit of a reach to get to, but it is an open area and keeps the higher voltage wires away from avionics and antenna coax cables. On the forward side of the subpanel is the invertor/dimmer control board, llightspeed Plasma III control box and the avionics cooling fan. Should have put the manifold pressure box there too, but I had a case of rectal cranial inversion (Head up A@$) and put it on the aft side (so I had to run the tubs through the panel after splicing into the ignition box) with the GRT EFIS RAIM GPS box, XM weather receiver, ADI Back up battery box, and the other things that are more likely to be accessed over time. Everything I anticipate needing access to is available by removing an EFIS screen, or reaching up on the firewall. The items on the forward side of the firewall are a little more challenging to get to, but still not that much more difficult.

Eric
 
jchang10 said:
So then did you start mounting black boxes on the aft facing sub panel first? It sounds like most have not had to mount anything forward of the sub panel then?
Click to expand...

I mounted a couple things that I don't expect to access frequently on the forward side of the subpanel (e.g. safety trim, avionics cooling fan). I did this while the entire top forward fuselage section was upside down on a bench, so it wasn't a big deal. If I do need to remove them, it'll be a pain, but not impossible.

Most things, however, I put on the aft-facing side.

-Rob
 
Boy, i still can't decide: cut big subpanel access holes like William or no, like most others.

Looks like Ivan also cut large access holes, for many of the same reasons. Continues for the next few pictures.

http://albums.phanfare.com/5187035/2292606_4807168#imageID=83785792

Frequently, i catch myself overdoing things. i just can't decide if this is another one of those occasions or not. Almost ready to flip a coin.

IMG_0178.JPG


I started marking out where to cut the radio stack. Then i figured instead of cutting out "just enough" for the radio stack, why not cut out plenty to the left or right. It would give:

1. Plenty of room for the avionics stack, including a future Garmin 430 upgrade.
2. In the future, if i decide to move the avionics stack further out to the right of center, the subpanel cutout is already done.
3. Give access to the firewall.
4. Gives plenty of room to route wires thru the subpanel.

The major downside is the loss of mounting real estate.
 
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Just a thought ----

One thing for you to consider is that the rear of the radio tray should be fastened to the sub panel, not just cantilevered off the instrument panel.

I am dealing with that at this time, and the task is a bit more difficult due to the over sized hole in the sub panel.
 
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