Avionics shelf structure

Hi,

I'm fabbing a couple shelves in the tailcone for ADAHRS, ELT, COMM, etc and wondered if there was an 'accepted/best' way to attach the cross angles to the longerons/stringers?

Have not found anything similar in 43.13 nor searching forums. From forum pix is appears folks have either (B) 'hung' the angles from the longeron (bolts?) or (A) trimmed off and tapered one flange of the shelf angle and laid it on top of the longeron.

Probably would be easiest to 'lay' the shelf on top and attach with platenuts but it seems the trimming of the shelf angles would reduce stiffness and shelf strength. Been a long time since I did any structure analysis lol.




-dave

ADAHRS

It doesn't answer your question but I built a shelf hanging from the J-stiffeners and bulkhead.

It would be easier to add your platenuts to the new cross piece on the bench rather than adding them to the longeron.

az_gila said:

It would be easier to add your platenuts to the new cross piece on the bench rather than adding them to the longeron.

Click to expand...

Good point Gil. I was going to use AN3 and AN365s to attach the shelf if I used 'B' above, as only the bolts would be supporting the shelf (under positive G anyway

(In the sketch, the longerons run into the page)

I am assuming that you will be using two horizontally placed angles to support the shelf plate. If so, then I would place the angles on top of the longeron angles as such L-----_|. This allows you to bevel / taper the shelf angle ends.

Me too

The couple we have placed back there in the past, worked best as in your "A" drawing. We have moved most of that stuff back up front however, so we could get full utility of our 8. We found that it works best if the empty weight of an 8 is as close to the forward C.G. limit as you can get it as every thing you load onto the airframe for a flight will be placed aft of that point. Just what we did. Yours, R.E.A. III #80888

Avionic shelf behind the panel

Does anyone have a drawing or plan of a shelf that can be used behind the panel. I don't have my plans in front of me but it would go from the brace at the rear of the gear towers to the bottom of the panel. They are at different heights. Trying to plan placement of various parts that go with my VFR, G3X panel. Thanks,

Rich

This worked nicely for me. I mounted the Dynon Skyview EMS and ARINC-429 box, one on top and one on the bottom, to this shelf.

That is just what I needed to see. Looks good. Any other ideas/fabrications guys?
Thanks, Rich.

Tray

I used a couple of short sections of piano hinge, riveted to the baggage bulkhead, so the entire tray can be easily removed. Will try to post pictures when I get back to my desktop.

Here the one I just made. I plan on mounting gea24, gsu25, and gad27 on it