Engraved America Captain 28" Shield With Backlight

I was asked by a coworker if I could make this project for her daughter's wedding. Apparently, the young couple are big fans of this franchise. The goal was a wall-hanging wooden shield with their names, wedding date, and the phrase "Endgame" engraved on it. I knew this was going to be a big job, but I thought I would give it a try, in part because the person who asked me to do this is amazing and constantly seeks out ways to make all of our work lives better, or at least more bearable (we are both nurses).

I hunted around on Thingiverse and found many models on this topic. I honestly don't remember which one I picked, I think I downloaded 2 or three and worked them up as models until I found one that looked like it would do the trick. My machine cuts 2" stock pretty readily, but much more than that gets iffy. After I sized the shield out to near the max size of my machine, I ended up flattening the Z a little bit to get it basically 1.75" thick hoping to leave 1/4" of the blank as a backing. It didn't quite turn out that way, but in the end, I made it work.

So I needed a 2" thick solid blank that a 28" circle could be cut from. At my local lumber yard I found a piece of red or soft maple that was 2" thick and 10' long. If I recall, this one board was about $105 at maybe $5-6/bdft. I cut 3 roughly 32" pieces from it, and the leftover piece I ripped a couple 2" wide strips that augmented to two sides just a little so I knew I had enough. I jointed all the edge surfaces and glued them into a panel, and flattened both sides on the CNC with a 1" surfacing bit.

My CNC is a 1st generation X-Carve that has been heavily modified with belt/motor upgrades, lift kits to the x-axis, stabilizers to the Y rails, an aftermarket Z axis, and a Demon controller.

I also used a little black acrylic paint for the lettering, and many coats of shellac, and after we decided to backlight it I purchased a couple of different LED light strips with battery packs and an RF remote control. To provide spacing off the wall I used a 3/4" piece of MDF about 2'X2"

When both sides were flattened I chose the prettiest side to be the face and secured the board to my CNC with the old blue tape and superglue trick. I drilled some pilot holes through the waste edge and used a few screws to try to hold the piece flat during that time. When you have a large unfinished panel that only one side is exposed to air for a period of time, even overnight, it is going to try to cup. This ended up being on the table much longer than the 10-12 hour total carve time, so despite this effort, it did cup a little and it made some extra work at the end, but I don't think you can tell very easily from the finished product. Woodworking, for me, is at least 70% learning to fix things I didn't do as well as I originally intended, and this was no exception.

I used the 1" surfacing bit for the rough carve. I normally use a 1/4" bit but this had so much material to remove I played with bits and feed speeds and according to the Vcarve estimate, a saved a couple of hours with this bit compared to a 1/4" end mill. Partially through the 2-3 hour rough carve, I noticed the machine was having a problem and I had to stop it. One of the pulleys for my 9mm belt drives had failed completely, spilling the tiny ball bearings and leaving the right y-axis motor disengaged. Fortunately, I caught it before the $100 board was damaged. But work froze while I ordered replacement parts. I took about a week to get the parts, and to have the time to install them, recalibrate the machine, and restart the carve. Once I did though, I zeroed the machine just a little bit deeper than the first attempt, restarted the rough carve, and it finished without issue.

In contrast, the detail carve went pretty smoothly. It took about 6 hours for the detail carve using a 1/4" ball nose bit. This is the largest ball nose bit I have, and I thought with the relatively straight lines and simplicity of this carve that it might work and (again) save a little time. It worked reasonably well though there were some areas in finishing that might have been better had I used a smaller bit. After the 3D carve I used a 60-degree V-Bit to carve the lettering. I realized later that I had specified a 1/8" endmill for clearing a 0.2" flat depth I believe, but I forgot to make that carve so the A's and M's and N's I think had some wonkiness, which I eventually fixed with a small chisel. Finally, I used a 1/4" endmill to cut the perimeter.

Before I could add a finish, I needed to attend to some details. I sealed the lettering with shellac, then applied black acrylic paint to the carved areas, sanding off any that escaped the carves and ended up on the surface. At this point, I realized my mistake with the clearing bit on the letter carving. I carefully chiseled those areas by hand to be recessed, then painted them black also.

The extra days on the table, while it was being repaired, had resulted in a little bit of cupping to the glued-up board. One side of the shield had a nice 1/8" backing, but the other came down to a sharp edge at the perimeter cut as that side had lifted a little during the carve and the wait for parts/repair. You can see in the first picture above where I added a few 1" wide strips of decreasing thicknesses on the right side of the back to bolster that edge a little bit. so that repair took a little unbudgeted time.

At some point, I suggested to my friend the idea of backlighting the piece, which she liked. I thought it would be relatively easy to do, and give the piece some pop at night or on special occasions I shopped around and ended up buying two light setups from the big-box store in the sky for about $12-15 ea because the remote control for the first one was infrared (IR) instead of radio frequency (RF). The RF one ended up working perfectly. I had the thought that if I shaped the piece on the back somewhat like the star, it might make the reflected light on the wall more interesting, being brighter at the areas around the edge which corresponded on the front to the points of the star at the center. This didn't really have any noticeable effect. When I cut the star-shaped piece I cut the circle also (just in case) and, to make it brighter, I ended up adding the circular piece to the back also, in order to put the lights closer to the edge. I also cut the cover for the door of the chamber in the 3/4" MDF for the battery pack and fitted it to the recessed area I had carved for that. I also cut a piece of white oak for a french cleat wall hanger and fitted that into the slot in the MDF I had carved for that purpose

Relatively late in the game, my friend told me that they planned to present this to the couple at the wedding reception, in some kind of dance that they had choreographed for this purpose (I know, I know... but it's her only daughter getting married, so at least she's not setting a precedent for 8 more lined up behind this one). So at 28"diameter solid with a 3/4" piece of MDF on the back, the thing is kind of heavy and I hadn't really counted on it being part of an interpretive dance, so I decided to add some temporary handles, mostly for fear of it getting dropped. I drew them out in my CNC software, carved, sanded them, and attached them with two carefully sized screws each.

At this point, there was a lot of sanding and card scraping. The recessed areas were a big pain, and I wasn't crazy happy with them, but they were too small for any power sanders and in the end, I did the best I could. The finish is about 15 thin coats of shellac, which I took a teeny bit of gloss out of with steel wool.

If I was going to do it over, I might look at a model with a smooth dome and carved lines to delineate the rings rather than the recessed rings so I could get a power sander to cover the whole thing.. Other than that, things went mostly according to plan. As always, I learned a lot. As you can see, I'm writing this 3 days before the wedding, which means I delivered this remarkably on-time, for me. I recommend putting the due date on the front of any project you make, as a way of keeping focused on getting it delivered on-time.

I hope this helps anyone thinking about something like this. I'd be happy to answer any questions about this or anything.