3D Scanning and Printing

Goals for Week 05:

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)

Group assignment page & design file:

Takeaways from the group assignment:

Surface finish is a measure of how smooth a 3D print is. A greater millimeter surface finish will result in a print that is "rougher" in appearance. The final print on the group assignment page, which took 3 hours and 7 minutes, is a great example of diminishing returns in terms of surface finish. The difference between this print and the 44 minute print are not noticeable, unless you were to get very close.

Infill is a structure that fills in the inside of a print, providing stability and strength. It acts as a support network that is customizable depending on the desired weight and strength of a print. Without infill, there could be warping and sagging of the print. There are numerous types of infill, but the two of the most common are grid and gyroid. In Wheaton's fab lab, we typically use gyroid infill because of its superior load-bearing capabilities.

Tapers refer to the widening or narrowing of a feature of a print. One part of the print is wider than another, such as in the case of a pyramid shape. Making a cone in fusion 360 and printing it is an example of an object that tapers.

Random Object In-class Print

Keyring Fidget Spinner Print from Printables

After choosing a model from printables, there is a button to open the model directly in Prusaslicer, which is what I did. However, you can also go to File > Import STL to import the model from an stl file.

I made my supports only be on the build plate for easier removal. Make sure Prusaslicer is in Normal mode. I used generic PLA for this particular print. After all of these are confirmed, we can press 'Slice now'.

To make the supports organic, we go to Print Settings > Support Material > Style > Organic. This is only accessible in Normal mode. Organic supports are lightweight and reliable.

The prints after generating organic supports. From here, we can select Export G-code. Save the g-code file to somewhere accessible. Plug in a USB stick to your computer's USB port, and copy the g-code file into the USB. Disconnect the USB and plug it into the 3D printer.

This is what our Prusaslicer will show when we've selected our file from the USB. It shows us the estimated time that the print will take. When we've confirmed the details, we can select Print.

The print in progress.

The finished prints. Remove the organic supports by hand or with a plier tool.

Non-Subtractive 3D Print Design: Circular Spinner Object

Fusion 360 Design, Prusaslicer Print

I started off by creating a sketch with a circle with a diameter of just under 1". I then extruded the circle to make this short cylinder.

I cut a hole in the circle to make a ring, then sketched another circle that would just barely cut into the existing ring. We're going to make an undercut with this method.

Cutting an undercut where another cylinder will fit and rotate using the extrude tool.

Using the fillet tool to allow for the other cylinder to move more freely, and not be stuck in place.

Below is the finished undercut, making this design nearly impossible to make subtractively paired with the ring- shaped design.

Next, we'll make the cylinder which will actually do the spinning motion by making a cylinder just barely smaller than the radius of the undercut.

To make the inner cylinder easier to spin, I decided to cut a hole into the cylinder and apply threading to make it easier to grip.

Next, we'll move onto importing the design in Prusaslicer.

For this design, I've decided to use organic supports. In the final printed version, I also scaled by 150% because the model was looking a bit too small to work without any errors. The threading also disappeared in Prusaslicer, and it was not present in the final physical print.