Spider Capos are very interesting musical tools that allow the user to capo individual strings on a guitar. All you need to create one of your own is a CAD program and a 3D printer (with filament, of course). This assembly is made up of 9 distinct, easy-to-design parts; The rod, the 2 end pieces, the 4 (or 6, see Step 3) pegs, and the 3 spacers. The way this assembly is designed, it can be used on either a guitar or a bass guitar. I printed mine for a bass guitar, but there is very little difference between the build for a bass and the build for a regular guitar. Sizes generally don't matter, as long as they stay consistent throughout the design process. The last thing to mention is that there is a locking system, made with drafted rectangles and spacers. This is a very fun build with a great result!
Step 1: Main Rod
The first step in the Spider Capo assembly is the Main Rod. Everything is built around the main rod. Sizes are subjective in this assembly, but this specific build is 3 inches long, 1 inch wide, and 1 inch tall. There is an extruded corrugated pattern on the sides, which allows the rod to fit in to the Endpieces (Step 2). Once you make the rectangle, cut a 0.5 x 2.5 hole through the rod and corrugate the insides with the cut tool, as seen in the picture. You will also need a small slit to account for the rod spacer (Step 4). Once you finish the insides, corrugate the outsides as you see fit. Then your capo rod is finished.
Step 2: Endpieces
The next step is the endpieces. The endpieces grip the sides of the neck of the guitar and lock the rod into place. Make a rectangle of any size, and extrude it to roughly 0.75 inches. Then cut out a hole in the middle that is the width and height of the rod. Then make room for a spacer. The shape doesn't matter, as long as the spacer slides in and out easily. Then cut out corrugation on the opposite side of the spacer. Then make at least one bar for the endpiece to rest on the neck of the guitar (one on the bottom is optional, but not necessary). Finally, make another endpiece with the corrugation and spacer on different sides that they are on in the first endpiece.
Step 3: Pegs
Step 3 is the pegs. The pegs are very simple, but very important. They actually press down the strings to do the actual capo-ing. The only necessities of the pegs are that they must be a little bit taller than the rod, and they must have one bar of the corrugation. The rest is up to the ol' imagination. Personally, I made the top chamfered into a pointed top to help with grip, and I left a small indention on the bottom so the string doesn't slide out from under the peg, but these are not necessary. Since this build can be used for any amount of strings, just print as many as you need (4 for bass, 6 for standard guitar).
Step 4: Spacers
Step 4 is the spacers. The spacers are also very simple and very important. They lock the corrugation into itself to, essentially, allow them to work. Again, most of this is up to the imagination, but it depends entirely on the space it has been left. The rod spacer (which holds the pegs in place) is just a flat, skinny piece the length of the cut in the middle, and the thickness of the rod space minus the thickness of the peg. The endpiece spacer is different, and more up to the imagination. The only requirement is that it needs to fit in the space you left, and it needs to lock the rod into the endpiece.
Step 5: Assembly
Congratulations! You made your own spider capo! Now, why are you still reading this? Go jam!