Propellers are easily lost or broken, and when they are, they add to the plastic waste in our seas. So BlueDotROV designed 3D printed biodegradable propellers to solve that problem.
As someone who explores and strives to protect the oceans, ROV pilots should be able to replace propellers quickly and easily, as well as reduce the amount of plastic we leave in the ocean.
That’s why BlueDotROV designed open source 3D-printable PLA (Polylactic Acid) propellers. PLA’s durability gives it a huge range of applications, from engineering plastics, to woven shirts. But, made from corn extract, PLA also has the unique ability to be broken down by naturally-occurring bacteria under stable and wet conditions. 3D printing propellers means that anyone with a 3D printer can render a replacement prop in under an hour. No more spending money on injection-molded propellers, no more waiting on replacements to arrive, and no more plastic waste from diy ROV builders.
If you’re building your own ROVs from scratch, BlueDotROV's website has 3D printed biodegradable propellers available in ROV kits, as pre-printed sets, and in the form of free and ready-to-print downloads.
Designing these props took some creativity. A challenge with printing propellers is that blades present a significant overhang. If overhangs are too steep, you need to print out support struts to prevent the blades from collapsing during printing. These struts can bind to the surfaces they support, especially when printing in PLA. This mangles the underside of your propeller blades, increases drag, and lowers your vehicle’s efficiency.
To avoid these problems, we increased the pitch angle of the propeller blades. Making the blades steeper relative to the print bed ensures that each layer of plastic is supported from below by a large overlap with the previous layer. The result is a 3D printed propeller that’s as smooth as your 3D printer’s resolution allows.
As with all BlueDotROV's products, these are very much a work in progress. If you’d like to contribute to design, download shape files and join BlueDotROV's forums!