What do you do when faced with an impossible task? Well in the rare case you need to manufacture an octopus with articulating legs, maybe you need a machine just as unique to make it! 3D printers offer a unique and relatively easy way to bring those impossible ideas to reality. There are many types of 3D printing, but the two we will focus on a resin based system and one that utilizes a plastic filament. The basic idea behind 3D printing is slicing an object into several hundred cross-sections and then slowly creating the later in the material layer by layer. Resin SLA 3D printers use ultraviolet light to harden each layer nearly instantaneously. On the other hand, FDM or FFF filament printers use a plastic filament that is extruded layer by layer. This offers more flexibility for the user, enabling hollow prints, control over rigidity, wall thickness, and infill patterns as well.

For this project, I decided to print three octopi using a Bambu lab’s FDM printer and two on a Formlab’s SLA printer. Both were fairly simple to set up and print, but the SLA prints required some post processing. In order to get the SLA prints to fully harden, I had to cure them in a UV light machine. Afterwards, I snipped off all of the supporting materials to get the finished product. This was a bit time intensive but it was worth the while. In the end, the printers nearly guarantee a perfect print (as long as the settings are set correctly.

The final products moved quite well and were very fun to play with. I was surprised at how well the printers were able to handle the tolerances on the linkages given the fact that the links were only a few millimeters thick!

Cost analysis:
Resin parts -Tough 1500 resin Formlabs: ~72 ml ($0.207/ ml)  = $14.95 per octopus

FDM parts – Generic PLA Filament: ~60g ($0.02/g) = $1.2 per octopus

Total cost for five octopus: $33.50