This post is actually written by Lidvin!
1. Introduction
Moving on from the conventional methods of production, we start to try our hands at the most revolutionary piece of additive technology: the 3D Printer! Though I don’t have much experience with 3D printers, I was very excited to do this assignment. Despite some things not going well, the functionality with certain printing methods and structures let me see the potential that some of these 3D printers have.
2. Process
First, I started by looking for something that I really wanted to do – I wanted to do a flexi animal, which consists of several interconnected joints that cannot be made otherwise (these joints consist of a square attached to an axel that allows rotational movement). My animal in choosing was the dachshund, as it is long enough to bend and rattle. Below is the thumbnail for the .stl file of the dachshund print I found on Thingiverse.com!
The “impossible” 3d structure.
The first 3D printer I used was Prusa to explore the FDM method to create objects. To do this, I imported the STL file into the Prusa slicer software, and scaled the print to about 50% of its original size, as the model was pretty big! After scaling it down to about 6cm in length and 0.3 cm in thickness, I proceeded to convert the file into .gcode and used SD cards to transport the files into the printers. For the most part, printing went fine, but sometimes, the filament would ball up because it was not adhering to the plates. I would assume this happened because of the dust and filament remnants that remained on the plates, but this was not a big obstacle and the 4 printed dachshunds came out well and were flexible enough to the point the dogs would wiggle! Once done with the FDM models, they were post-processed through sanding. This leaves the printed flexi-animals smooth.
Using the Prusa software, I sliced and organized the dogs to be printed.
One of the dachshunds after sanding.
After using FDM printers, I decided to use the FormLabs SLA printers. I pretty much did the same process with this printer, but with this one, the file transfer and preparation were much quicker than the other printers. For SLA, I had to iterate many times to get something that could have worked, but most of my prints from the resin printer were failures. After 5 attempts with different sizes, supports, and curing times, I was able to turn in one tiny dachshund; however, the figure fell and the tail snapped off and got lost. Since I did not have time, I had to salvage the remains of the tailless dog and submit it with a replacement FDM dachshund. Though the resin print did not come out as expected, it gives a bad situation a funny twist.
3. Evaluation
After printing all of my figures, 4 out of 5 of the dogs came out appropriate, except the resin one. For the filament models, mistakes are common and all you need to do is edit support, infill, orientation, or simply change the machine you’re using. However, for the SLA machine, I and some other people found ourselves struggling to print interlocking joints with resin. Either the resin completely fused the joint, or it made the joint too stiff which caused a lot of breakage. This shows me that FDM printing is very good for interlocking joints and structures, but not resin. Resin is best for maintaining well-made structures and geometry, but it is not great at making small joints. (Maybe it could work if the joints were bigger, but we are limited to the size of the gumball.)
4. Cost Analysis
All Printers were provided by the OEDK
Matte PLA 3D Printer Filament: $25.99 per spool (Amazon.com)
FormLabs GreyPro Resin: $199.00 (Formlabs.com)
Labor: ($18.13 per hour): $36.26
TOTAL: $282.80 (with tax)
