What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

Radio stack cut out width

storkeye

Member
Friend
I'm in the process of drawing up my panel on FreeCAD ready for cutting. I'm planning on installing a Garmin system with a GNC 255 radio, GNX 375 navigator and GMA 245 audio panel.

Looking at other peoples panels that have been cut the radio stack seems to be a standard width but when I check the manuals for all 3 devices they require different width cut outs.

Is there a 'standard' width cutout that I can use for CAD or is this something that is undersized and then final sized when installing the device?
 
A little slop will help

When I build my -7 I made the width of the radio stack cutout exactly 6.25 inches as that was the standard width of all the avionics, and the racks etc. all installed fine (SL30, GTX-327). When I replaced the GTX-327 this year with the GNX-375 I naturally assumed the rack would slide right in, unfortunately I found that the 375 rack was exactly a couple of thou wider than 6.25 inches. As the rack support sides behind the panel were aluminum alloy angles it was not a simple filing job to get the rack to fit.
I would suggest giving yourself a little width wiggle room for the racks and use spacers as necessary for the mounting screws.
YMMV
Figs
 
Cutout

Yes there is a standard with 6.25" for the cutout.
This applies when mounting the rack from the back of the panel.
It is the most common situation with a relatively thin panel as in a small aircraft. Having a thicker panel the rack have to penetrate the panel to get the
radio to latch properly. This requires a slightly larger cutout.
However a larger cutout can´t be noticed when the radio is in the rack.

Good Luck
 
Yup

I have nearly the same equipment and just went thru this. The GNX375 was a pain because it was a little off from the others.
I recommend you get the trays and fit them when cutting the holes or programing the CAD machine. The trays have little tabs the stick thru the panel’s hole for proper alignment.
Also, Garmin does not do a good job of dimensioning the height of the stacked avionics. The true height I had to find by trial and error; the drawing dimensions just weren't right when the boxes were stacked due to the face plate overhangs.

When I do this again for my RV15, I am going to cut a metal trial mockup to get the dimensions right before committing the dimensions/ design to a panel blank.
 
Last edited:
Back
Top