Pi Radio – It’s Alive

I had mentioned the Pi Radio project to my co-teacher and he was pretty enthusiastic about working on it. Since he is the coding expert, I decided to let him work out those specifics, while I work on the CAD aspects and building the project once the electronic portion is complete. Today he successfully coded the Raspberry Pi to tune to different internet radio stations using a rotary encoder, which will mimic using the tuner from the radio to ‘tune’ to different stations. Additionally, he has incorporated a second rotary encoder for volume control. Everything seems to be working now, but still some work finalizing the code and electronics.

For my part, I’ve started putting the entire radio into CAD in order to make all the new interior components to hold the new electronics. I’ve finally finished recreating the outer housing, and took a quick photo to show how well it came out. Looks just like the real thing. Next, I need to create some new components for lasercutting and 3D printing.

Milling

Today I started milling a part that will become a student project. The idea is to have each student learn how to mill their own Arduino holder. The holder allows for easy prototyping, and will give them hands on knowledge of how to use CAD and CAM to to setup a part.

The CAD aspect of the project utilizes a spec sheet in order to get mounting hole dimensions for the Arduino. Students will learn how to import a canvas into Fusion 360 and calibrate the canvas to the correct size. Next, students can build their holder directly on the canvas. Additionally, the CAD project requires importing components from McMaster Carr, and then using the CAM features of Fusion 360 to create the tool paths on two sides of the part. Lastly, the holder requires a laser cut top. Here is an image of the project below.

 

I was able to setup the CAM today and began cutting stock to size. This process started with making 3 cuts on our vertical bandsaw to a large piece of aluminum stock and then placing the stock on our Trax mill to get more precise with the stock dimensions. I am looking for a stock size of 3.2 x 2.6 x 0.8 inches.  Below are some images of cutting the stock.

Volume Control | Parametric Modeling

One of my favorite aspects of my job is solving a problem we have never before encountered. Luckily, this happens nearly every day as students are building various types of projects of their own design, such as candy shooters and singing toothbrushes. 

A senior was having problems building a box for a bluetooth speaker setup they were working on, as they were trying to understand how to build the box with the proper volume specified for the speakers he was using. He was taking measurements, putting them into CAD, but when things changed within his project, he would have to change all his dimensions again and it was a real tedious task. 

Working together we were able to solve the problem using parameters in Fusion 360. We utilize Fusion 360 for all our CAD needs in the classroom. It’s an easy to learn, robust software with built-in CAM that enables us to send our models to all the different machines we have in the shop – 3D printers, waterjet, plasma cutter, mills, lathes, etc. It’s also free software, and I have the ability to setup an educational account and give access to all my students, rather than having each student setup their own personal account. I really like the way they have the new educational account setup for teachers and students, makes life much easier than before where students needed to verify their accounts which was often problematic.

Back to the parameters discussion. By utilizing parameters in Fusion 360 along with an organized modeling strategy, we found a way to control the volume of the box so it always remains constant, even when we change the length, width, or size of material. Below is a screenshot of the parameter setup for the project. You’ll notice some odd math happening, as there are several instances of multiplying 1 in within an expression. This is because Fusion 360 does not have in² or in³ within its parameters framework, so you need to use the 1 in to cancel out parts of an expression so it has the same units Fusion 360 can work with. 

I went ahead and created a quick modeling video for students, so in the future I can just point them to the video instead of showing them directly, which frees me up to help other students in our classroom. Video below.