Building the Case
Now that we have our models, we need to make the laser cuts and assemble the pieces. You’ll probably want to practice a few cuts beforehand, and make sure you’ve got everything planned out. Measure twice, because you can only cut once! I opted to go for a hardwood case to match my keycaps, and having wooden peripherals leads to a very unique look.
Cutting your Boards
The exact methods for making your cuts will vary drastically depending on a wide variety of properties. The material used (wood vs plastic vs metal), the thickness of the layers, the speed/power of the laser will all change the settings for your laser cutter. I’d recommend consulting anyone you may know with more experience cutting for advice. However, there are a few things I learned myself that you will want to keep in mind.
Keep your files in order!
I made a few mistakes and changes in the middle of the process, and forgot to keep track of which models were correct, which were bad, and which I needed to re-cut or fix. This turned into a mess of wasted material and frustrated sanding to repair mistakes that simply wouldn’t have happened if I had kept my ducks in a row.
Make critical cuts a little wide
After I had made my cuts, I noticed that since I had them at the exact size of my components, the fit was a little too tight. I had to go through and sand/file down a lot of my boards to allow the components to fit snugly. If I had increased the size of my screw holes very slightly, there would have been enough room for my standoffs to fit properly. This will vary, of course, on the laser cutter and it’s operation.
Make the right cut
Cutting with too much power, too slowly, or with gunk in the way can all affect the quality of your cut. Remember that the laser works by burning material away – you’re going to have to monitor just how much you remove. Make sure everything is flat so you’re cutting straight, and do a number of practice cuts on scrap material so you know how everything is going to turn out. You will probably have to do multiple passes as well.
You’ll want to do some practice cuts. Start with low power on a piece of paper that you have taped down to the cutting surface. Use this to line up your future cuts. Move on to thicker material, such as cardboard and a piece of scrap, until you’re confident your cut will be clean.
Plan the number of middle layers
Since this design works by ‘sandwiching’ some middle layers in between the top faceplate and the bottom, you’ll want to know just how many layers to cut for your standoffs to work. It’s okay to cut an extra just in case, but you’ll want to have enough!
Make your Cuts
Go make your cuts! Even if they aren’t perfect (I know mine weren’t) you can fix it all with sandpaper and a little elbow grease. Here are how mine turned out:
As you can see, they were charred around the edges and needed a lot of work to clean up. I wound up using my router table to finish the cuts that didn’t go through all the way on the laser, and this caused pieces to break! The blue tape you see is holding them together until the wood glue cures… whoops!
What I wound up with was one bottom plate, 5 middle plates, and one faceplate. I fixed the screw holes (because I didn’t do them right the first time either…) and got started on basic assembly.
Let’s give the pieces a light sanding with sandpaper and wipe them off. This isn’t totally necessary as we won’t see the top or bottom of the center pieces, just the outside. We’re going to do a full sanding later.
Assembling the Parts
Assembly is pretty straightforward once the pieces are ready. The middle layers are stacked up, and a hex standoff is placed through each hole so that they are held in place.
We’ll then countersink the top and bottom screw holes. Be very careful with this step, we can easily break the faceplate if we aren’t careful. Practice on some scrap first! For those who are unfamiliar, countersinking lets you put the top of the screw flush with the face of the wood. Here’s a picture:
Remember during assembly that the faceplate will be fragile as it is quite thin. You don’t need to put the screws in very tightly, as that could break it. It’s just a numpad after all!
Lets grab our sandpaper and use some elbow grease to clean up the inside, since the cuts probably aren’t perfect. We’ll clean up the outside so that all of the pieces match together smoothly. We can use a disk sander to speed up the process, or could easily do this by hand as well, but we invented tools for a reason. After sanding each individual piece, let’s assemble everything together and sand it as one piece, which will give us very smooth edges.
After we’re done with rough sanding the pieces down to size, let’s some fine sandpaper by hand. This will cause the wood to become quite smooth, and give it a very clean look. I made sure to be extra careful with the faceplate, as it is very thin and a risk for breaking. I’m very pleased with how mine turned out!
Things are already looking really good; you can see the countersinking on the faceplate very clearly in the pictures, and at this point we’d be ready for the electronics. I decided to put in a few switches just to make sure.
I decided to finish the wood to see how it would look. Since it is a numpad, it wouldn’t see much wear and tear (and no weathering) but I wanted to see how the finish would affect the color. I used some danish oil and, following the instructions on the container, applied the finish to the faceplate as well as the rest of the case.
As you can see, it turned out great and I am very happy with the look. The finish made things a bit darker which really matches the keycaps and compliments their color range.