Removing bumps on avionics trays

While trying to line up (the 400W bezel seems slightly taller/thicker) a GTR200 on top of a 400W, the front bumps (I'm assuming it's a spacer bump for removing/installation and cooling) interfere with each other when the bezel faces are flush. The bumps are are riding on top of each other making it hard to position the stack for securing and the gap between the 2 units looks kinda big.





The bumps on the rear of the unit fit much nicer together.



Can I file the bumps off of one on the trays to get the racks to sit nicer and reduce the gap between them?
Am I doing something wrong?

Thanks, Andy

Leave them...they set the min space between racks allowing adequate room for the cams at the bottom of the units which are used for insertion, removal and locking. Also, be sure to leave the same space below the bottom rack.

Study the cams on the bottom of the radios while inserting and locking the unit into the rack and you'll see the need...

As you show in the back, one bump will give you the adequate spacing. The fact that the bumps line up on the front shows a possible lack of planning on Garmin's part, especially since they don't line up in the back. Slide the GTX back to the bumps don't line up and verify that there is adequate clearance to slide the radio in and lock it. If so, then you could grind off one of the bumps.

As others have stated, you will need some space between the units, so you can't or shouldn't get rid of them entirely. Typically there is no need to get rid of the bumps anyway, after you get everything in the stack the position of your bumps may not be exactly where they are right now, so I'd maybe do a new fit check on it at that point.

I've seen people grind them off before, only to have to go back and put a "shim" or washer between their trays because they ended up getting radios stuck in the panel. I have however occasionally seen them slightly flattened if need be (but not usually ground off).

Just my 2 cents as usual.

Cheers,
Stein

Thanks for the replies!

I found the need for the locking mechanism clearance while stacking the boxes on a countertop. I think filing one of the interfering bumps will give me exactly what I'm looking for. Thanks again!

Thanks for the idea Stein, flattening the offending bumps did the trick! Much better than grinding....



Everything seems to fit together correctly, I've got a temporary .063 spacer between the GMC305 and the GTR200 to match the gap between the GTR200 and GTN400W. I made a little wiggle room when I originally made the panel angles, a .020 shim along one side snugly takes up the space without squishing anything. Now to drill some holes!