BJD wheelchair WIP: hard moulds & puzzle casting

Mon, 16 Jul 2018 20:03:06 +0000

Unfortunately unsuccessful attempt at puzzle moulding: saving silicone/moulding rubber when making a large hard mould by only putting a part of the prototype through all the steps required, and merging the hard mould parts together afterwards. Which can be done if the prototype is fairly uniform, like with a tire.

(Small parts on sketch show puzzle CASTING: Where it’s the cast end product that is being merged together, not the mould- something I abandoned for the tire since I couldn’t keep the thickness of the cast consistent, resulting in weird overlap)

Step 1, photos 1-2: Embedding & moulding only one quarter of the tire prototype. Step 2, photos 3-4: Casting a silicone replica of the prototype. Provide with core (metal wire) to keep it somewhat sturdy & manageable. Step 3, photo 5: Support silicone replica with break-away structure and coat in layers of resin (or clay/plaster, if the form is suitable for that) to create hard mould. Repeat for as many puzzle pieces as necessary. Step 4, photo 6: Assemble puzzle pieces, depending on the fit some sculpting/ filling and/or a supporting cover all around may be necessary in addition to glueing the pieces together.

With so many steps there’s an awful lot that can go wrong, and due to slight changes/shifts somewhere during step 3 (most likely when re-fitting the silicone replica to the support structure between puzzle piece 1 & 2), one piece turned out a bit wider than the other, even though the pattern lines up pretty well. I could try amending this by sculpting, but it’s a difficult angle to work on, will almost certainly take just as much as carving & moulding the rest of the prototype, and I’m not certain it won’t show on the eventual tire.

Decided to mould the entire tire after all. I’ll just make the (first) mould as thin as possible to save on silicone. -.-

how not to on Puppit Productions

BJD wheelchair WIP: hard moulds & puzzle casting