I print functional shoe lasts from PHA. They withstand 200PSI, heat activation, and exposure to harsh solvents.
Hey, I'm a climbing shoe resoler and PHA has really made 3D printed shoe lasts viable in this industry. I consistently print with minimal support and little to no defects. I occasionally have a failed print, generally from a clogged nozzle or issue with the spool. Some of the key things I've learned:
-I replace that strip of tape the last is on every print.
-I use double walled adaptive cubic infill. Single wall fails for me because PHA is so slow to harden out of the nozzle that it sags on itself as the layers go up. You can print single wall infill that layers vertically (doesn't overhang), but single wall in general is too weak for my use with pressure.
-The outer wall is three layers, and I use the geekdetour bricklayering script.
-I point the last toward the printer's cooling fan. Helps maximize cooling as layers build.
-I use a 0.8mm nozzle.
Pictures of my settings: https://www.dropbox.com/scl/fo/4h8gfl3s3eryvd59b133n/AHyosbAzfFw2SncEYRbUdS0?rlkey=zcjb2iux91tiqri2exvrsp6ix&st=safqveoi&dl=0
I have just one issue! PolarFilament is out of stock (plastic spools), and EcoGenesis uses cardboard spools. I've had too many failed prints and issues from cardboard spools that I'm really wary of using them. A single one of my lasts is about $15 dollars in filament, so a failed print suuuuuucks. I wanted to check if there are any current refillable spool solutions for the cardboard that EcoGenesis uses, and if there isn't can I request someone make one? I've seen ones where it seems to just fit over the existing spool that look nice to use. Electrical tape doesn't fix warped cardboard.