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Permalink Reply by John Austin on November 29, 2014 at 3:37pm

Kevin,

There are many ways to approach this! Are you suggesting a "hinged-down" panel where the entire panel tilts down? Some have done that. Not quite sure what you meant about installing a tray, though? I took another approach and have now installed 3 sub-panels in my 750. With a sub-panel, you just remove a few screws and that entire group of instruments is pulled out. It also provides a generous access hole to reach things behind the other sub-panels. Some have installed access panels on the top of the glareshield, but I personally think that is of limited value because it is hard to easily see and access things by looking/reaching up-and-over-and-behind the vertical instrument panel. That being said, Walt Snyder made an easily removable tray in his glare shield which neatly holds GPS pucks, etc., and provides some access behind the panel, too!

John

N750A

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Permalink Reply by Kevin Lippert on November 30, 2014 at 8:45am

John,

Thanks for the reply. I was considering pull out tray, then maybe some type of hinge for the panel (I did find the pics of this, too complicated).  I like the sub panel idea and seems fairly easy.  Any suggestions from your experience?  Anything you would do differently?  Pics?

Thanks

Kevin

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Permalink Reply by James R Depfer Sr. on November 30, 2014 at 10:43am

Although I didn't think about it at the time, and the forum posts on the subject were after I completed my panel, I would do what John suggested. The dynon will probably not be the only instrument you'll want to access from the back later on.

Without any front access to the instrument wiring, etc. I've spent hours just making a minor "ONE" wire repair, and a small modification without front access. Its not easy laying on your back trying to do something up under your instrument panel.

All of my access problems are really John's fault, since he originally recommended the access panels after my panel was done :)

I do have one question, concerning access panels though. What do you do to keep wiring up out of the way, and at the same time have enough slack to pull the panels and instruments forward to get access ???

Jim

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Permalink Reply by Walt Snyder on November 30, 2014 at 12:44pm

Kevin,

The sub panel way that John describes really makes it easy for access, and it doesn't get any simpler. I kept my panel very simple, and all of my switches and breakers are on one sub panel where you undo 4 screws and you can pull the whole thing out for access. I also have an MGL glass panel, which provides a huge access area, merely by undoing 4 screws and pulling that out with a service loop. The key is the wiring the service loop.

You have to keep in mind while you're wiring to allow a service loop in you wiring, the length depending if you want to just have the sub panel or glass panel hang out a few inches or further, On mine I can pull it out about 12 inches from the panel, which seems to be fine for me. The loop is bundled and then zip tied to allow me to pull it out a little and then cut the zip ties if I want to extend the full service loop. 

My transponder and comm also have the service loop, to allow me to pull it out and disconnect the harness, etc outside of the panel. It's not really a loop per se, just enough wiring to pull the glass panel, the sub panel, avionics, etc out for access and not have to go underneath for anything. 

Another thing to keep in mind if you go this route is try to keep it simple and all switches and breakers in one area, etc, so your holes should only be for your glass panel, one for the breakers and switches sub panel, and one each for you comm and transponder, and maybe one for anything else you may have. The only other hole I have is for my ELT, which has to be there. My switches for trim, flaps, AP are on my stick, (HOTS concept, hand on throttle and stick) which enabled this set up. Even if you do have other electrical items on you panel, the access by you glass panel alone should make it easier to get to them. 

There's unlimited set ups and approaches on panels, and simple and in the field access is what motivated this one. There's a lot of other pretty sweet ones I'm sure you've seen, and the sub panel approach could probably be used on those also.

Walt Snyder

You can see how the MGL would provide a huge access when it is removed, and how the breaker/switch sub panel would be easy to work on with the service loop. (this one is the mockup of the final one and just resting in place. That's a SAT phone peeking it's head over the glare shield tray)

This is the removable tray for stuff that usually sets on the glare shield that John mentioned. The bonus is it also provides access if needed

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Permalink Reply by John Austin on November 30, 2014 at 4:18pm

I can't add too much more to what has already been mentioned. I found that .063 is plenty sturdy for the subpanels so they will lay flat, etc. Make at least one sub-panel big enough to accommodate the largest EFIS you could ever conceive installing. Also, it works perfectly OK to overlap the sub-panels so that one row of screws holds the edges of two sub-panels. I personally like stainless screws with nutplates - you're going to be taking them in-and-out more than you would think and the stainless holds up well and doesn't scratch easily, etc.

I originally only put in two sub-panels and "permanently" made cut-outs in the base panel for several things. In retrospect, I wish everything had been installed in sub-panels! So, later, I added the third sub-panel by cutting a hole in the base panel and overlaying it with the 3rd sub-panel. I only needed to add one additional nut plate for this one, so I used a free sample of a "Click-bond" nut plate which is bonded rather than riveted ... works great. However, they are pricey if you have to buy them! Here's some before-and-after pics of the new sub-panel which shares screws with another panel. The orange thingy sticking out of the panel is the Click-bond fixture that aligns the nut plate and holds tension on it 'til the adhesive cures.  You can see where I outlined in red where the new installation would overlap the existing panel:

John

N750A

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Permalink Reply by John Austin on November 30, 2014 at 4:59pm

BTW, the one big boo-boo I made when originally doing the panel is that I did not allow enough service loop for the Ray Allen trim indicator! To completely remove the sub-panel, I have to remove the 4 tiny, tiny screws in the back of the trim indicator to let the LED unit and attached wires slip out. Ray Allen Co. very graciously sent me a new external housing (for free!). I'm going to make up some sort of "slip on, slip off" back to the housing case so I don't have to fool with those tiny screws ... drop one of those babies and they're gone for good! Ha! 

However, even if one has a generous service loop, there still is no easy way to disconnect the wiring from the indicator - so, maybe that one would do better "permanently" installed rather than in a sub panel!

John

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Permalink Reply by Richard Simmons on December 1, 2014 at 7:15pm

I added access panels on the outer cover.

Attachments:

• IMG_5742.JPG, 1.7 MB

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Permalink Reply by John Austin on December 2, 2014 at 7:23am

Very nice! Looks like very professional workmanship!

Your approach works great on the 601/650 because the canopy swings up and out of the way. However, since the 750 (like Kevin and I have) has a fixed windscreen, access above the panel is not totally out of the question but is less useful because the windscreen and braces are in the way when one tries to look in from above.

John

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