LED Light Box

For our sophomores we have a few standard projects they all work on individually. These include the LED Light Box and SumoBot projects. For each project students are expected to complete their projects using their own CAD designs, as well as making their own PCBs and designing the circuitry from scratch.

Unfortunately, for our current seniors, due to the COVID pandemic, they were unable to work on either of those projects, as they spent nearly a year and half learning remotely. Luckily, they are back in the building this year, and working hard to catch up on some hands on activities they missed. One student is now close to completing his LED Light Box, and it’s beginning to look very professional. I’m not sure what the inspiration for the acrylic is, but it came out really well. We use a raster technique for student designs on the back side of the acrylic and mirror the design so it looks backwards on the surface it is being laser etched into. When you turn the acrylic over, the design is in the correct orientation, and looks very clean behind a few millimeters of acrylic.

There is still some finishing work to be done on this particular LED Light Box, but it’s a nice example of projects coming out of our shop. Our current sophomore are beginning their lightboxes right now, which generally begins with finalizing their circuitry on breadboards and then milling their PCB boards on our Bantam Tools mills. Enjoy the photos and video of the project below.

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.

Toothbrush Fix

"If you can't fix it, you don't own it."

I don't recall exactly where I first heard this mantra, for some reason I recall it may have been after watching the movie Maker, but it also may very well be from using iFixit on several occasions for iPhone repairs. Either way, it resonated with me, and is something I continually remind my students each day.

Reminders without context, however, are often fruitless. Our students tend to recognize and implement the meaning of such a mantra when paired with a concrete example. As luck would have it, yesterday my wife's toothbrush stopped working properly.

Additionally, one of my students has been working on creating a electric toothbrush band, and I have spent some time working with them opening and tinkering with different types of electric toothbrushes.

So, instead of throwing the broken brush away, I began a YouTube search on how to fix the maligned equipment. Turns out, there are thousands of videos online showing you how to open up and fix all varieties of electric toothbrushes. After examining several videos, I was finally able to find one that showed similar symptoms as my toothbrush which you can find here, and was able to safely open up the casing, extract the hardware, and locate the issue, which happened to be a shearing of a metal part.

A few dollars spent on Ebay, and hopefully I will have this toothbrush back to working order in a few days. By exposing my students to real life scenarios of fixing rather complicated objects, will hopefully give them the confidence and curiosity to take on the challenge of fixing an item rather than simply replacing it.

Will post an update once finished. For now, here are a few photos of the opened toothbrush and the broken Tip Linkage, which needs replacing.