For our first post-midterm project, we were tasked with producing “impossible” objects using multiple 3D printing techniques. I was looking forward to this project, as I have very limited experience with 3D printing but am hoping to become more skilled in it due to its many applications and uses. 

The first step of the project was to pick out an object to make. I decided to create a flexible lizard that I found on Thingiverse.com; I thought it was cute, I loved its ability to move, and it seemed to have the right level of complexity. Once I had selected the lizard, I downloaded the file and uploaded it to the 3D printer computer in the OEDK.

 I decided to start out with FDM printing using the Prusa printers, as this is the method of printing I was most familiar with. I uploaded the downloaded file to the software and scaled it down to 75% of the original size, as I wanted to ensure it was able to fit in one of the gumball capsules we were required to put our final objects in. From here, I was a little confused as to whether or not I needed supports for the object (and, if so, what kind of supports were necessary). I initially tried printing with supports everywhere, but had the problem of the object not adhering to the printing bed. Next, I also added a brim around the shape. This helped with the adherence; however, the supports everywhere proved to be too much, and I broke my shape trying to remove them. Finally, I printed with a brim and supports just on the build plate. This worked great, and after removing the extra material, my lizard looked and moved just like it was supposed to! Once I’d figured out the correct settings, I printed a few more lizards using the FDM printer.

The next step was to use a second kind of printer – for this, I selected the FormLabs SLA printers. It took me quite a while to find a time when they weren’t in use (the first few times I tried to use them, they were both in use for extremely long 10-14 hour prints). Once I found an open time, I was surprised by how simple the process was. Like with the Prusa printers, I uploaded the file, this time to the PreForm software, and scaled it to 75% of the original. Then, I generated supports as I did on the FDM printers and began my print! About 2 hours later, I came back, removed the print bed, and placed it in the bath to wash for 20 minutes. Finally, I removed it from the bath and UV cured it for 120 minutes. 

When I returned to the OEDK the next day, my part was finished! Unfortunately, the supports were much harder to get off than with the FDM printers, and the resin seemed to have stuck to itself, so I had to pull apart the individual segments of the lizard in order to make them move independently. In this process, I ended up breaking the lizard tail due to not being careful enough, which caused me quite a bit of frustration. So, I headed back to the OEDK and went through the process again (at about 1AM), this time being more careful when removing the supports. This print turned out well, with the only issue being that I wasn’t able to get the back legs to move; I was nervous that if I pulled at them too much to free them, I would break them off (as one started to break when I tried), so I decided it was best to leave them be.

Finally, I had five lizards! The one from the SLA printer, while the exact same size, is pretty clearly different from the others, both due to the color and the different material (the SLA lizard is a bit stretch/softer than the others). Overall, despite some frustrating moments, I am happy to say I am now confident using two types of 3D printers.

Cost Analysis:

Cost Type	Cost	Price	Source	Quantity	Total
Materials	PLA	$9.99/600g	Amazon	25g (estimate)	$0.40
	Resin	$20/1000g	Amazon	12g (estimate)	$0.24
Labor	3D Printer Operator	$19/hr	ZipRecruiter	1 hour (just time preparing printers, not time actually printing)	$19
Overhead	Facility Cost (Machine Time)	Assume 15% of labor and materials	Rockler	N/A	$6.18
	Quality Control	Minimal time spent	N/A	N/A	$0
Design	Engineering and Development	$43.12/hr	ZipRecruiter	30 min	$21.56
Total	$47.38