For this assignment, we were tasked to 3D print an impossible object. This object could only feasibly created using 3D printing techniques. After looking through Thingiverse, I finally found a file that I thought was interesting. For this project, I decided to 3D print a Hexagonal NASA Fabric by DiArchetype. This is a chain mail kind of material with various links that can move a fair amount.

First, I used an FDM printer to print the fabric. I tested various sizes and realized that the smaller I made the fabric the harder it was to move overall. I decided to go with a larger size that could still fit within the constraints.

Once I determined the scale of the fabric, I printed the rest of the pieces of fabric. Overall, the process on the FDM printers was relatively smooth and troubleshooting could be performed easily.

Unfortunately, once it came time to use the SLA printers, I ran into many more problems. To start off, the support settings and the orientation of the piece was a nuisance. The piece would easily break off and the print would fail early if the orientation wasn’t optimal. This error also wouldn’t be apparent early on in the print like on an FDM printer. In addition, because of the close nature of all the moving parts, the printer would also fuse the separate parts together. This inhibited the movement and creating a solid piece. Unfortunately, I did not have enough time to continue varying the settings and modifying the file in order to create a successful print on the SLA printers.

Cost Estimate:

• PLA filament for 4 pieces of fabric – $0.94 (~$0.24 each)
• 7 hours of FDM printer machine time – $12.00 ($3.00 each piece) (JLCPCB)

Total Cost: $12.94

Pt. 2

In order to obtain a successful SLA print, I had to look for a different file that would be compatible with the SLA printers. For this, I found a file for Three Stochastic Easter Eggs by DaveMakesStuff that had complex surface and inner geometry. I thought this file would be better to print on the SLA printers because of the lack of moving parts and solid figure. I also thought this could be printed relatively easily on the FDM printers.

To start off, I scaled the file to 50% in order for the eggs to fit in the gumball capsules.  I then printed four eggs on an FDM printer with a simple brim and with no supports. The print came out really well and had a lot of detail.

As the FDM printer was starting, I started slicing the egg for the SLA printer. The pre-generated supports for the model had a lot of internal supports that I thought would be really difficult to remove. To remedy this, I removed all of the internal supports and applied my own that supported the entire structure with fewer supports. Then, I sent the file to the printer. This file was much better for the SLA printer and it  came out great. Once the printer was done, I washed the egg and cured it. Then I took off all of the supports, which was much easier than I expected. The bottom supports and the main inner supports came off as a group and I just had to take out the small supports from in between each layer. The final product was incredibly detailed and was worth the effort.

Overall, the five eggs came out really well and I found the design really satisfying and intriguing.

Cost Estimate:

• PLA filament for 4 stochastic eggs – $0.93 (~$0.23 per egg)
• 12 hours of FDM printer machine time – $24.24 ($6.06 per egg) (JLCPCB)
• Resin for 1 stochastic egg – $0.04
• 5 hours of SLA printer machine time – $1.56 (JLCPCB)

Total Cost: $26.77