This entire project, not just 3D printed portions, was modeled using Autodesk Fusion 360. The renderings and screen grabs you have seen throughout this tutorial were all created using the software. Although it can be quite expensive to purchase a license, it is available for free use for students and for hobbyists and companies making less than $100,000 per year. It is a powerful CAD program that is especially well-suited to 3D printing. The most powerful part of the program is that it remembers each step used to create the design and allows you to go back in time to edit earlier steps. The effect of those edits propagate forward into the later steps. It also allows you to parameterize your design with user-defined numeric values that can be easily edited. When you change these values, everything dependent upon those values changes as well.
In the files you downloaded for this project in the "3D_models" folder there is a file titled "NeoPixel Clock.f3z". Open up Fusion 360 and create a new project. Inside the empty project at the top of the screen you will see an "Upload" button. We will need to upload this design to your account. All files in Fusion 360 are stored in the cloud so we will have to upload them to the cloud to use them. When the files have been uploaded you will see several objects. This model consists of a main model called "Clock" which contains links to other components. You only need to open the main model to make changes.
We have added several user-defined parameters that allow you to easily tweak tolerances and features of the model. You access the User-Defined Parameters under the Modify toolbar. It is the last option "Change Parameters". You will see the following pop-up appear.
Of particular interest would be the values ScrewHole which is the diameter of the mounting holes for the doublet board. SensorHoles is the diameter of the holes for the IR sensor and photocell. The values IRx and IRy are the position of the hole for the IR sensor. Similarly PCx and PCy are the position of the Photocell hole. SplitTolerance is the gap that is cut to split the faceplate and frame ring into multiple pieces. If you have trouble assembling the pieces you might want to increase this value. You can click on any of these parameters, change the value, and the model will update automatically. Then you can export the pieces as STL files and print them again.
As mentioned before, one of the advantages of Fusion 360 is that it keeps a timeline at the bottom of the screen that keeps track of the steps necessary to create your design. By editing this timeline, you can make changes to the model and everything will update automatically assuming you don't make too many drastic changes that ruin future references.
As we have constructed this model, the final two steps of the design are to split the ring into four pieces and to split the faceplate into five pieces. If you backup the timeline 2 spots, it will undo these changes and you can export these pieces as single solid pieces presuming your 3D printer is capable of printing such large pieces.
We had difficulty printing the faceplate with the tiny holes. The 3D printer draws the little rings around the holes and then tries to fill in the spaces around them. But if those tiny little rings don't adhere perfectly, everything can get messed up. We chose to create a one layer plug 0.1 mm thick that will fill in the NeoPixel holes and the sensor holes for the IR sensor and photocell. You then later have to drill out these holes. If you want to try to print the parts with the holes predrilled you can modify the model to eliminate these plugs and export the STL files again.
On the left side of the screen where all of the components are listed, hover your mouse over the "plate" and then move slightly to the right and click on small circle that will appear. This will limit your timeline to only the steps necessary to construct the plate. Then look at the bottom of your screen in the timeline. If you hover your mouse over each of the steps you can see what it does. The second from the final step in creating the faceplate is to fill in the 2 sensor holes. The third from the final step is to fill in the 60 NeoPixel holes. You can right-click on these steps and delete or modify them to suit your needs.
When you have finished making these modifications, go back to the top of the list of components and select the entire model by hovering your mouse over the top item and then clicking on the small circle to the right of it. Save your file after making these modifications.
In order to export the modified file as an STL file, click on the "Make" button in the upper right corner of the toolbar. You will see a pop-up on the right. You should uncheck "Send to 3D print utility". Then click on the body that you wish to export. For most of the model you can use medium output but for the ring to get the best quality of the curve we suggest using high output in the drop down box. When you click okay you will be given a dialogue to save the file to your hard drive.