Mouse is a commoditized product available for dirt cheap cost these days (Amazon Basics mouse $5). So why would you want a DO-IT-YOURSELF mouse. Well, I wanted to explore 3D printing and how it can be used for making something that is useful on an everyday basis. Mouse is a perfect object which let me do exactly that, since it has good amount of mechanical design involved.
The process involved making a circuit board consisting of a micro-controller and optical sensors, making a case for the mouse and making sure the PCB and the click buttons mate well with the body of the mouse. I will keep this tutorial post focussed on the making of the case: how I went about making paper sketches for the case and made the case with help of mechanical designers through multiple iterations.
Step 1: Paper Sketch of the Case
Every project starts with an idea and ideas represented visually can be not only be used for reflecting on your thought process but can aide in communicating your idea to others with ease. Hence I made a rough paper sketch of the model as the first step.
Step 2: CAD Modeling Using ProtoDnD (protodnd.com)
Given my modest knowledge on CAD modeling tools, I wanted to try making this model myself. Although I had tried a number of modeling tools (Autodesk Inventor, Rhinoceros, Sketchup), my acquaintance with the tools was not sufficient to make something that looks and works like a mouse. The translation from a paper sketch to digital model was not easy. This is when I came across a design service community called ProtoDnD, http://protodnd.com. I decided to hire an already trained CAD modeler and get the model made efficiently, so that I can spend my time on rest of the things.
Step 3: Design Process
As soon as I provided the first paper sketch one of the designers for ProtoDnD asked me for the dimensions. I put together a PCB which had three constraints on the design of the case:
- a window for the optical sensor and
- pods for screwing the PCB to the base of the mouse and
- a solid mating had to be ensured between the two switches on the PCB and the buttons on the case.
Once I made the PCB with 4 holes at he corner and zeroed in the optical sensor and switches used as mouse buttons, I revised the picture with my measurements. I added the dimensions on the image already uploaded through ProtoDnD's web interface .
Step 4: Showtime: Output Model From Designer
I finally received the a model from the designer on ProtoDnD and this is what it looked like. What is shown above is the final output from the designer. When the designer uploaded a first version of the model, i realized it might be useful to have a hole for bringing out the debug and programming interface for the micro-controller on-board. I conveyed this to the designer by annotating the STL model directly on ProtoDnD's web interface as seen in the 4th image.
Step 5: Real Stuff: 3D Printing
I finally printed the mouse in a Objet 3D printer.
The mouse was finally fitted with the PCB. To get the positioning of the sensor and buttons right, it took two iteration. And finally I had a beautiful 3D printed mouse. Yippee !!
If you want to know more about the project electronics and components, I would be more than happy to share. Send me a message if you would like to know more about this project.