I know there is a BJD construction thread. Is there a vinyl or plastic version? Is this even a thing anyone has tried?
As far as I'm aware vinyl dolls are made with the help of metallic casting forms, which is why their production is a lot more expensive to start. However, they allow afterwards for easier mass production. I'm not so sure it's possible to do this easily at home. Even resin casting can be tricky because without a pressure pot and other expensive tools you will be unable to cast bubble free parts.
Unlike casting resin, which you can pretty much cast from your garage (how garage kits got started), you can't do that with other types of plastics due to how they are process and also the molds you need to cast the parts. You need industrial equipment to make the molds, and pretty much a factory to melt the plastics. You can see a very cool quick version from Obitsu making one of their Kewpie vinyl dolls here -- the mods are pretty expensive to make, due to the materials you need to make them alone. Hope that helps a little. (:
There are quite a few folks around 3d printing bjd/bjd hybrids, if that counts… but that’s generally outside the perview of DOA, I think?