I made it at TechShop!
I wanted to move my work computer's audio connection out from under my desk/behind the CPU to a spot where I could reach it without crawling on the floor in my work clothes. Having an AC to USB charger under my desk was a non-starter for the same reason. I did have a hole in my desk though, and wanted a tidy way to put all those things in arm's reach.
This is where 3D design and 3D printing come in. Once you've mastered the workflow and understand the basics of 3D design software, a solution like this isn't hard to implement!
Step 1: Tools and Safety
More detail is available about the pictured tools in my Basics of 3D Design instructable.
I used digital calipers and a digital protractor for this design. As you'll see in later steps, the USB power converter had some odd angles at the place where I wanted to integrate it into my desk, so the protractor came in very handy.
The calipers and protractor have pointy/sharp parts. The laser range finder is not eye-safe. 3D printers are about as dangerous as a coffee maker, but read the manual, watch videos, and/or take a class to learn how to use one safely. The hot end of a 3D printer gets up to about 200 degrees Celsius.
Step 2: Commercial Products
I chose this particular extension cable because the male end has a smaller diameter than the female end, and that would allow me to use a simpler design.
I also used a 14" zip tie and an extension cord from my box of parts (not pictured). Both of these are available at department or hardware stores.
Step 3: Measure
Since I couldn't move my cubicle from work to home (where I do the CAD), I brought my measuring tools to work.
I used a measuring/recording app to store the results, but a piece of paper would work too. I prefer the app, though, because my pictures are faster and better than my sketches. The other image shows the digital protractor in action, measuring one of the many odd angles on the USB charger where I wanted it to pass through the final design.
With all of the dimensions recorded, we are ready for the next step...
Step 4: Design the 3D Shape
The embedded video is an overview of the design process. It leaves out all of the data entry and menus. For a better idea of how those work, check out this series of tutorial videos from Autodesk. After watching them and playing with the software for a few hours, I had all the skills I needed for this project.
Step 5: Unsure? Print a Test
The first part of my final design that I modeled was the part where the USB charger would pass through.
Why? I had guessed at the dimensions of the arch across the top, and did not want to print out the final piece only to discover I had guessed wrong. I wanted it to be snug, but had erred on the side of too snug. Even though I did guess wrong, printing a test piece saved me time on the 3D printer (and plastic).
Even though one of the great features of parametric design is that you can go back several steps in a design to fix an error like this, it is still worth it to run off a quick test piece.
In a different project, where I was adapting a design to fit over my tub faucet, I went through about five iterations before I got everything snug.
Step 6: Slice and Print
Step 7: Check Your Work
The audio extension cord is snug enough in the part that it doesn't move when I insert or remove earphones.
A 14" zip tie is long enough to go through the two loops and hold the USB charger in place. The zip tie is flat enough that it still allows a secure connection between the USB charger and the extension cord.
Step 8: Share Your Design
This is a rather specific design, but other designers might be able to adapt it to their circumstances.
I uploaded several versions of the file to the Autodesk Vault.