Fisherck

Glad you enjoyed it!

It's the little things in life right now! It always helps to have a bit of humor

That looks great! Nice use of plywood and watercolors on each layer.

Great idea, thanks for the suggestion! That's a nice easy way to make sure that they stay rigid while the epoxy is setting, but I can out the silicone mold after to make getting them out easy.

Glad you like it! I just added a pdf file of the project up with the other file types. I haven't used PDF before for laser cutting, so though it looked good to me when I exported it, let me know if you have any problems with it.

Glad you enjoyed it! And good question, my mixing ratios were by volume.

Glad you enjoyed it! It's become one of my favorite personal projects because of how simple the design ended up being, plus it's easy to customize the engraved surface. I'll definitely be using this in the future as a gift idea.

Glad you liked the Instructable! The purpose of gluing the two pieces together into one is to essentially make the map as thick as the bottle caps (~1/4 in), which helps keep the bottle caps in place (they won't get accidentally bumped and pop out). Instead, you could laser cut the map out of 1/4 inch plywood (the laser cutter I was using could only do 1/8 in). You also could probably get away with just using one 1/8 piece as well, you would just need to be a little more careful when putting the bottle caps in.

The material that the paint is on should not have any affect on the resistance (as long as the material itself isn't conductive). You can control the resistance by either changing the amount of graphite powder you put in the paint, or by how much of the conductive paint you apply to the paper (a thicker coating will be less resistance). Paper should work fine, but one thing I would be careful about is making sure to not bend the paper too much after the paint is applied, because that could cause the paint to crack and break the circuit

For the most part, the bottle cap size is pretty universal. I haven't found any bottle caps that won't fit this. I designed the cutout so that the 4 semicircular grooves were just a little larger than the diameter of the bottle caps, so that they would have an interference fit. This will allow a little bit (but not much) of leeway, and if the bottle caps are smaller, they won't stay in place, and if they are too big, they won't fit.

Glad you enjoyed it!