RV-9A Subpanel mapbox question

jlfernan · #1 08-04-2007, 08:11 PM

To any junior or aspiring engineers out there...What is the purpose for the subpanel? Is it a structural member or is it there just to provide support for any deep instruments/avionics? The reason I ask is I just started my mapbox install and while looking at some folks websites, I've seen some funky things!
The instructions are very confusing and the photos Vans includes made things worse. Just wondering.

bsacks05 · #2 08-05-2007, 07:24 AM

Jorge,
I'm not sure what the exact function of the subpanel is but I did not want to cut into mine. Instead, I shortened the map box to about seven inches. Maps don't fit now, of course, but I still put lots of stuff in there. Batteries, checklists, flashlight, etc...

jlfernan · #3 08-06-2007, 10:12 PM

How are you supporting the back of the box?

bsacks05 · #4 08-07-2007, 05:54 AM

Jorge,
The angle around the front of the box is the only support. Since I cut the box down there is realy not that much weight to worry about.

N941WR · #5 08-09-2007, 06:21 AM

Jorge,

Some place in the directions Van's mentions you can cut that sub-panel as needed.

Because of my panel layout I did not install the map box but did cut a hole for my radios and transponder.

Good luck.

flybill7 · #6 08-09-2007, 06:42 AM

Quote:

Originally Posted by jlfernan

To any junior or aspiring engineers out there...What is the purpose for the subpanel? Is it a structural member or is it there just to provide support for any deep instruments/avionics? The reason I ask is I just started my mapbox install and while looking at some folks websites, I've seen some funky things!
The instructions are very confusing and the photos Vans includes made things worse. Just wondering.

Jorge, I am almost done with the mapbox. Did it strictly by the plans. The only tricky part was figuring out the vertical dimension of the subpanel cut. The drawings show a horizontal dimension but not the vertical. But it wasn't that big a deal. The subpanel angles support the mapbox end, not the subpanel itself, so you can rivet the angles where they need to be. I have pictures of the install on my page. http://www.pilotbill.com/Panel/Panel_30Jun07.html.

Bruce Reynolds · #7 08-09-2007, 09:08 AM

The subpanel is only about 8 inches from the panel and most radios, transponders, etc are about 12 inches deep. The subpanel provides support for these items. The subpanel could be a bulkhead just like the rest of the bulkheads aft of the baggage compartment, but it is there to give you comething to attach things to. You can't just attach radios to the panel alone, they must be supported at the other end of the tray also. It's the same with the map box. When I first flew my -6A, I had vacuum gyros installed and they were long enough that I had to cut large clearance holes in the subpanel for them. I have since removed the gyros and now I just have a lighter plane.

Bruce Reynolds
RV-6A, 450 hours (on grass)

kentb · #8 08-09-2007, 09:59 AM

I would add 3/4x3/4 angle around the hole to give the radio something to rest against. This also strengthened the sub-panel. I also place uhmw tape to keep the radio from being rubbed the wrong way.

Kent

alpinelakespilot2000 · #9 08-09-2007, 11:08 AM

I am planning on putting my mapbox very low on the instrument panel if possible. As a consequence, I will need to notch out the bottom of the subpanel. (It seems like about 1/3 of the back of the box will hang below the bottom flange of the subpanel.) I'm wondering if it would be sufficient to attach a doubler to the subpanel, reinforced with the angle, that extends low enough to wrap around the bottom of the map box. Is notching out the bottom of the subpanel any worse than cutting a square hole up higher on the subpanel. Any thoughts?

kentb · #10 08-09-2007, 12:37 PM

Quote:

Originally Posted by alpinelakespilot2000

I am planning on putting my mapbox very low on the instrument panel if possible. As a consequence, I will need to notch out the bottom of the subpanel. (It seems like about 1/3 of the back of the box will hang below the bottom flange of the subpanel.) I'm wondering if it would be sufficient to attach a doubler to the subpanel, reinforced with the angle, that extends low enough to wrap around the bottom of the map box. Is notching out the bottom of the subpanel any worse than cutting a square hole up higher on the subpanel. Any thoughts?

Its position was about 2 inch below the bottom of the sub-panel. I used three pieces of 3/4 angle to frame the sides and below the EFIS unit.

Kent