Pouring the v4 plaster beer bottle mold

This project is a testament to my wife's patience with me using her kitchen as a mold making shop. Most of the tools I need are there. I nice stable table to run two 3D printers, lots of room and plugins, electrical appliances, utensils and supplies of every type, good lighting. And pleasant company!

I have already poured PMC-746 rubber into 3D printed block molds and have printed and put in place stabilizers to hold the rubber in place. Embeds are in place on both the bottle base and bottom mold (upper right). The flexibility of this rubber is amazing, it make possible extraction of the plaster base, although with difficulty. It also preserves the embossed logo on the foot. This is version 4 (version 5 will have a shallow base piece and modified sliding natches).

Related Pictures

Yikes - Version 3 ceramic beer bottle drawing mold obsoletes previous

Something I love about 3D parametric CAD is how a drawing can evolve to be both simpler and better. While my version 2 drawing had about 20 steps, this one is down to nine. No more ribs, no offsets or mirrors in the sketches, no double-revolves and no seams across the mount ads. Printing will be dramatically faster. The quality of the side rails is now the key factor in final mold accuracy (these stabilize it while filling with plaster from the back).

I now draw the simplest repeatable shape: A one-quarter slice. Step 5 cuts the bottle profile from the solid block extruded in step 4. The preceding steps were a sketch of the bottle and block outline and a plane and sketch for the pad. Steps 6 and 7 are the extrusion and corner rounding of the pad cutout (near the rim). The last two steps mirror this quarter upward to create the block and then shell it to hollow the back side.

The drawing is now fully parametrically resizable, I have taken advantage of that to make a stubby bottle test. Neck spline points are now spaced vertically as a percentage of the neck height parameter - set at "70" here. The body and neck heights are separately set now so the full height is now a driven dimension - it is 146 here.

Three-piece vertically printed mold with natches

These 3D prints slide into slotted side rails for each pouring of plaster. Since the plaster releases easily it is possible to use these multiple times. This method is suitable for prototyping in larger quantities than prints that integrate rails. These are printed on edge so print times are drastically reduced and surface smoothness is much better. This version has a bottom piece eliminating the seam across the base. It also enables putting embossed logos on the base. The holes enable mounting flush embeds - making it possible to sand the mating surfaces flat before gluing in the natches. The three-piece mold produced is shown on the bottom.

3D printing case vs block molds for ceramics

Left are case molds, they are made by 3D printing the positive profile on a backplate (with holes for natches). These are secured into slotted rails. Right is a block mold, it is made by 3D printing the profile of a working mold with integrated rails. This one is printed vertically in four pieces. It is held together and straight with printed brackets. We pour rubber into these to make case molds. Each method has advantages and issues.
-Case: Faster to print. Easier to draw. Joins cast as easily removed bumps on the working molds. This is only suitable for prototyping, making one working mold.
-Block: Much more attention is needed in printing, there are more issues with orientation of print, infill, printed support, multi-piecing, fit and seam-filling. 3D drawing of these is more difficult. And block molds are bigger because they are molds of molds. They also need to be more precise to merit the cost of the rubber.

Links

URLs	https://plaster.glazy.org/ Glazy Plaster Calculator
URLs	https://bottles.beer Say goodbye to ordinary glass and elevate beer with ceramic bottles.
Projects	Beer Bottle Master Mold via 3D Printing A project that took several years of failures and blind allies and is finally coming together - so much simpler than expected!

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