HOW TO: Fixing the AM Armor Back Plate Overlap Issue

[A.J. Hamler[TK]]

Now, if there’s a consistency among owners of AM armor it’s that they love their armor and consider it the best around.  However, AM owners admit that the armor does have a couple quirks and the bottom edge of the Back Plate is one of them.  

 

For some armor, the bottom edge of the Back Plate has a nice, flat return edge that mates flat on the top edge of the Kidney Plate.  AM armor is different: That bottom edge isn't anywhere near flat, and the outer tips bend down and out like little "wings."  The end result is that no matter what you do, those wings will overlap the Kidney, which is a no-no in general, and a roadblock to attaining Centurion.  This detail from the back photo from my EIB submission shows the problem:

 

 

Notice in the above photo that the actual bottom of the Back Plate is right on top of the Kidney where it's supposed to be (red arrow), but those wings overhang at the sides (green arrows).  What's worse, with those wings overhanging they tend to pull the Back Plate out and down over the Kidney pretty much every time you move.  Here's a look at it from the side with the armor on my worktable.

 

 

How bad the overlap is varies from Trooper to Trooper, depending on body characteristics.  If your upper back/shoulders arch out at an angle, it's a bit easier to get the bottom of the Back Plate to rest atop the Kidney.  In the photo below, I'm holding the Back Plate out at an angle, and you can see that it almost works.

 

 

If your back arches out, great, but even if the Back Plate is resting in the right place along its width at this angle, good luck getting it to stay there -- your strapping is likely pull the Back Plate down over the Kidney every time you bend forward. 
 
I had brought up this issue way back during my build and got a number of suggestions, most of which dealt with heating those wings and bending them up to make them level.  But I could tell that heating and bending would really warp the side edges of the Back Plate because of the amount of return edge I'd retained there, so I balked on heating.  

 

I corresponded with JustJoseph -- who also has AM armor and knows exactly what this issue is like -- and he agreed that just trying to reshape them with heat could badly mis-shape the side edges, and suggested that the only real way around it is to start cutting off return edges to reshape those pesky wings.  Again, I put it off because I wanted those edges to stay (my shoulder blades tend to push the Back Plate out, creating gaps at the side that I wanted to minimize with as much return edge as possible).  You may feel the same way, but if you want to reach Centurion level those edges have to be dealt with.
 
After giving it a lot of thought, I determined that a combination of return-edge trimming and heat would be the best way to go and that’s the fix that worked for me.  I started by outlining the cuts I planned to make, and here you can see my proposed cut on the sides...

 

 

... and, rotating the Back Plate, you can see how that proposed cut moves along the outer tips of the bottom.  My proposed cut line ends short of the center of the Back Plate, leaving most of the return edge along the bottom/center in place.

 

 

It took a while to pencil in these cut lines, as I kept redoing them to ensure I started with the minimum amount needed -- I didn't want to cut too much.  I wanted to do this in extreme baby steps: Do some cuts, then do some heat and see what I got.  Then trim some more and heat some more, and check it out.  By the way, remember that last photo above.  You'll see it again a bit later.
 
So, first I used Lexan scissors to cut off most of the waste up to my lines.

 

 

After that, I used a cutter drum on my drill press to shave the Back Plate smoothly down to my lines.  Don’t have a drill press?  A sanding drum in a Dremel-type rotary tool won’t be as fast, but it'll get the job done.  Then, I heated those trimmed wings up using a hair dryer and did some bending, starting with the right side wing.

 

 

In the photo above, you can see the result after several cycles of trim/heat, trim/heat, trim/heat.  I was indeed taking it slow.  Satisfied that I had the right side as good as I could get it, I did the same trim/heat, trim/heat, trim/heat routine on the left wing.

 

 

OK, both sides are looking pretty good, and you can see how the bottom edge is now more or less straight across with no corner wings dipping down.   Lastly, I heated both sides a bit more to curve the outer edges inward to more closely match the curve of the top of the Kidney to help the Back Plate rest more firmly in place.

 

 

This whole process may take several hours, but it’s best to go slowly.  You don’t want to trim any more than you have too or, worse, ruin the Back Plate and have to buy another one and start over.  Hey, remember earlier when I said you'd see that photo of my proposed cut lines again?  Well, here's that same photo, but I've superimposed red lines where I ended up making my actual final trims.

 

 

Yeah, I ended up taking a lot of plastic off, and as time-consuming as it was it was worth it when I reassembled all the straps and hung the torso on my mannequin to see how it came together.  As they say, your mileage may vary -- you may not need to take off as much; you may need to take off more.  The amount I cut and reshaped ended up looking like this:

 

 

That's about as perfect as I think it can be.  I still don't like the way the AM armor isn't flat along that bottom edge -- that bottom return edge is angled, not flat.  I may address that somewhere down the road and you may want to, as well.  But this fix will eliminate the issue with the overhanging Back Plate.

 

A.J.