3D printing and scanning
Design and 3D print an object (small, few cm3, limited by printer time) that could not be easily made subtractively
3D scan an object (and optionally print it)
For this week, I wanted to print attempt to print in place a miniature and movable version of my final project,
Scanning
I needed to scan my battery pack into a 3d model, and looked to fab academy graduates for reference. Polycam is very easy to use, but requires precision to get a good result. Polycam annoyingly does have the processing fail, without giving a reason why.
In researching the reason for my first scan's failure, I found that too many photos could overwhelm, and I needed something that would be kept constant and easy for Polycam to track. upon learning this, I used different colored tape to mark out constant tracking dots
This setup resulted in my first working scan, but I still had a really obvious issue, the bottom of the battery was not visible. This, compounded with the other issue of the shadow acting like a hole, which would result in a bad scan. I fixed this by finding a random 3d print, and setting the battery pack ontop of that, as seen below
After successfully scanning, I was only able to output as a glb from Polycam, but easily found an online converter to change it into an stl. this stl is attached inside the design files at the bottom of this page. the link to the file stored on polycam servers, which probably won't last too long, is here. I was impressed with its detail, especially with the 1206 components on the board, and even the pins on the usb-c connector. An issue with the well scanned version is that it does not have a base, but using fusion 360's built in mesh repair tool simply connects all the missing parts to form a flat plane on the bottom, and other software would probably preform similarly.
3D design that cannot be made subtractively
After scanning my battery, I wanted to start on the 3d printing. In order to reach the weekly goal of making something that cannot be made via subtractive methods, and work towards my final project at the same time. I decided to modify my design from cad week in order to put in the basics of it eventually moving. I started by redesigning the entire head, because it was slightly on the wrong side
After redesigning the head to make it centered, and the window a bit more visually appealing, I started working from the base up designing mechanisms to make it move. None of these should come anywhere near what it will end up being, but work as a proof of concept.
in order to support other moving component, I added a ring on the inside of the base. This ring is meant to support the moving base.
After making the ring on the base, I added 2 legs directly below the arms of the moving section of the base. These arms are meant to rub against the base, in order to keep a stable height.
I then started to work interfacing the head with the arms, for this I made an indent in the side of the arms and a bit that juts out on the head, which comes together to hold it steady. This is also the main part of the design that cannot be made subtractively, as hollow shapes are hard to make subtractively, and round shapes are hard but not impossible to make.
After designing all 3 parts, I printed them out at 15% scale in order to save time. They took about 1.5 hours total, at ultra draft quality. Even at this low quality, the bases fit together well.
I did have an issue with the connection of the head and the arms, but I just scaled the head up to be 5% bigger than the other pieces, and thanks to the flex in the arms it came together.
while it does move the way I want it, the head is much too loose, and I defiantly need a better way to hold it on in the final build. I also need to figure out how I am going to make it all, but it will probably end up being the sphere head is exactly small enough to fit on a bambu lab a1 printer or even an x1 carbon, as our lab has one of those with a .8mm nozzle. I also have to fix some small bits that this print pointed out, like the walls being too thin on the arms holding the head
Group Work
For my group, I set up the framework of the site, printed the designs, and made the zip file of all of our designs. My group work can be found here, and a copy of the group work without images below
Overhang Test - Noah Smith
Overhang in 3d printing are the parts of the print that are not directly supported underneath. An overhang can lead to bad print quality, due to the plastic physically drooping, and even print failures. In order to fix overhangs, supports are used. Supports are easily removed parts of a 3d print that are placed directly under overhangs.
The easiest way to test overhang is to create a bunch of them, and look to see how the print turned out. I did this by making half of the gateway arch, with the final being 85 degrees.
Overall, the final print showed that after about 50 degrees, the bambu a1 mini started to struggle, and leave minor print artifacts, and at above 70 degrees it would have major flaws.
Design Files
all 3 parts of the camera, as well as the 3d scan files, can be here