By Natalie Pellette

For my impossible object, I decided to continue my theme and print an interlocking dolphin design from thingiverse. I got approval for my design from the TAs, however they warned me that the joints might be challenging to print on the resin printer. I decided to do four out of the five objects on a Prusa printer and one on the Form Labs printer.

First Print

My first print was unsuccessful, but educational. I learned that interlocking joints are challenging to print functionally at a small scale that would fit in the gum ball capsules. Not only were the joints not functional, but the dolphin pieces broke apart when I tried to remove them from the support because they were so small.

 

Second Print

I chose to prioritize the success of the print over fitting it inside the capsule and doubled the length of the dolphin from ~32 mm to 75mm. This tripled the print time, but led to successful interlocking dolphins!

 

Third Print

I printed my last dolphin on the Form Labs SLA printer using the larger 75 mm dimension. I then used the wash and cure machines for 15 minutes each. The print was unsuccessful because one of the joints fused together and two of the joints came apart when I was trying to pry the pieces off of the print surface. The head piece was so strongly adhered to the surface that when I finally pried it off, it shot into the air and fell down the stairs and  into the OEDK basement. Luckily, I was still able to find it. If I were to redo this print, I would use the optimal orientation setting on the form software. The dolphin would have been aligned vertically with supports rather than flat against the printing surface, which I believe would have allowed for easier removal and better joint printing. 

 

Conclusion

I was definitely more intimidated by this assignment than others, but ultimately it made my successful prints feel more rewarding. Even though my resin print was not successful, I feel comfortable enough with the various printing softwares and process flow that I would be able to try a printing project on my own and troubleshoot if needed. 

 

Cost Analysis

Time & Labor Costs:

$ = labor time x wage

2 hours of work time (not including wait time for prints)

$ = 2 hrs x $15 /hr = $30

 

Resin Costs:

3 prints, each totaling <$2 based on the 3DPrinterOS estimate 

3 x $2 = $6

 

Printer Costs(for reference):

Prusa i3 = ~ $1000

Form Labs SLA Printer = ~ $3750 – $10,000+

Form Labs Form Wash = $600

Form Labs Form Cure = $750

 

Total Cost = labor + materials = $30 + $6 = $36

I chose to exclude the cost of the machines since they are already owned and operated by the OEDK.