Wood Sign
I wanted my sign to look old and weathered, so I started with some old redwood fence boards, carefully harvesting them from a derelict fence.
I trimmed them to the size and shape I wanted on a table saw, then ran them through a planer to get them to an even thickness. The laser cutter I wanted to use has a maximum depth of 1/4", so I planed them to 1/4".
My sign is 18" long by around 11" tall. I made two panels of this size and held them together with painter's tape, and printed out a mockup of my lettering so I could get a good idea of the sizing.
Then I took them to my local maker space for laser cutting. I'd emailed over a vector file of my font design ahead of time, and they were all ready to cut it for me when I arrived. The cutting took about 15 minutes per side.
Having tape on the back of the boards made it much easier to keep track of all the pieces, like the cutouts inside the "B" and "A", which will need to be glued back in later on.
I cut two panels and did a mirror-image of the text on the back panel. The sign reads backwards from the back, but this way the light passes all the way through the acrylic from either side.
Acrylic Panel
I used 1/4" acrylic, since that is almost the same thickness as the NeoPixel strip. But what type is best? There's a product available from Tap Plastics called Chemcast Edgelit Acrylic, which is around $20/sf. I already had piece of 1/4 extruded acrylic on-hand, which is a bit cheaper at around $15/sf, so I did a side-by-side comparison to see if the Chemcast was worth the price.
Conclusion? I couldn't tell the difference between the regular acrylic and the fancy Chemcast version, so I'd recommend going with the cheaper / easier to find variety.
If you're building an indoor sign like I am, it's easiest to attach the LED strip with clear packing tape. Not much sticks to the silicone sheath but packing tape holds them firmly and invisibly. I wouldn't use it in an oudoor setting -- better to use Devcon Silicone Glue if you need something weather-proof -- but the glue is messy and hard to use, and the packing tape goes on in seconds.
In order for the whole surface to glow, we need to rough the acrylic up a bit. I tried a variety of different grits of sandpaper and found that the rougher I made the surface, the brighter the glow. 220 grit sandpaper seemed to work really well without leaving a lot of visible individual scratches. Sand both sides for maximum glow.
I sandwiched the acrylic panel between the two sides, leaving room at the top for the microcontroller and IR sensor. I placed the sensor near the top of the sign so it could stick out a bit, and be easily picked up by the remote control.
I ended up hanging the sign really high in the air, and if I were to do this again I'd put the IR sensor on the bottom edge instead. Having it on the top makes it a little hard to reach with the remote.
I added narrow chopstick-shaped pieces of fence board around the edges of the acrylic panel, to block the light, and tacked in a couple of blocks near the top for more structure behind the hanging hardware. I tacked everthing together with wood glue and finishing nails.
I plugged the USB cable into the Feather before nailing everything together. This design does not easily allow access to the Feather, but as long as the USB cable is in place I can reprogram it if needed.
I finished it off with a hand-turned signpost and 45 degree crossbar for bracing, and added a recessed lag bolt from the back of the mounting board into the post for added stability.
I used knotted jute rope to hang the sign from the post and threaded the USB cable up through the rope knots and through a hole in the signpost, where it hides inside a narrow channel cut into the top of the post on the table saw.
Text editor powered by tinymce.
