Isaac Iyengar- 3D Printed Capo

In Class Assignments:

Original Sketches:

Flatware: (Slap bracelet fork)

Murakami Flower: Mockup

Culture: Traditional Indian Serving Bowl

Part I need: Capo for Guitar


For this project I chose the prompt that had us make a part we needed. I made a guitar capo, which is a small tool that pushes down all the strings at a particular fret. This allows you to play a guitar in a different key, while using the same fingerings for chords without the capo. 

Essentially a capo is a clamp that can fit on a guitar. Normally these cost around $10+, so I figured 3D printing this part would be a cheaper option.

Below is an example of a standard capo:

Image result for Capo

Below is my first iteration of the capo. I modeled it after the above image. While I got the shape and dimensions correct, this design wouldn’t have been functional since it needs to be two separate pieces with a spring in between to allow the clamping functionality.

I wanted to avoid using a spring and instead wanted to see if a design that was a single piece was possible. Most 3D printed clamps I had seen involved using a screw, however this would be no different than using a spring. 

This led to the design below which was made using OnShape, an online CAD software that allows functionality similar to Fusion 360, but free. I sketched out a design that took the clamp and shape of my previous design, and used a spiral design that could coil to allow flexibility. 


Below is the Extruded and Filleted 3D Model of the final design. In the process of designing this capo tried to develop better CAD practices mainly using constraints such as dimensions and tangent tools to produce a more accurate result. The use of tangent allows for connected curves to be much smoother. 

In terms of the design I think this design allows future improvements, such as the addition of a case for guitar picks (often misplaced), and potentially personalization. Personally the design reminded me of the Leaf Village symbol from the show Naruto, so I’ll play around with the CAD more to resemble that while still having the clamp functionality. I’m not a huge fan of the way 3D printed text looks, so instead may make a sticker or paint it. One thing to note this design was made for my guitar which has a slightly larger fretboard, so this design may not work as well for smaller guitars. 

Below are three viewpoints of the piece.


Final Product:

I don’t want the plastic hitting the strings directly as this may produce a buzzing sound on the side that touches the string, and scratch the wood finish on the side that touches the neck of the guitar. To solve this I will add some foam tape to the portions that are in direct contact with the guitar. The print itself turned out very nicely and is able to function as a clamp on the guitar strings, however it needs to press on the strings with more force. The addition of foam or hard rubber to the clamp portion will solve this issue. The print took 1 Hr 30 Min to complete, including a raft. There were no issues with the print, my one worry was the lack of support for the curved clamp, but I chose an appropriate angle of incline, such that the printer had no issues with it. 

I have noticed the hinge isn’t able to retain its original shape after multiple uses. Potentially need to increase the infill of the print to fix this.