3D print this rail to pour plaster jigger molds for mugs

Turn this upside down and center it over a plaster or 3D printed form of the outside shape of a mug. This creates a mold that drops down in our Shimpo cuphead. This opens slightly along one side for easy release from the plaster after set. It is held together by paper clamps during use. The upper flange can be glued down to a smooth surface with a clay slurry. If you would like this 3D file in Fusion 360 format, it is available in the Files manager in your Insight-live.com account (click the link below to go straight there).

Related Pictures

3D-design a flange for clamping a shell mold

This type of shell enables holding the mold together with paper clamps, making for easy removal when plaster is set. Here is the simplest way to draw it.

-Draw the jigger mold profile like shown below left (we use a 0.8 thickness outline).
-Draw another 6-8 mm outside it, that will be the flange.
-Revolve the mold profile 359.5 degrees, leaving a small gap, perhaps 0.5mm.
-Rotate the flange (with join operation) 0.5 degrees (hopefully producing 1mm thick, adjust as needed).
-Rotate the flange again (with join), but in two sides of -1.0 and 0.5 degrees (creating the other flange).

Notice the details that enable printing this upside down without generating any printed support. The printed PLA is left on the plaster mold above and below the shoulder, enabling precise fitting and good wearability.

3D-Printed rail to cast working plaster jigger molds

The multi-use grey outer rail on the left was printed in two parts and glued together (at the shoulder). Its vertical split enables me to open it a little. The center model of the outside contour of the mug (on a two-step base) was made by casting the plaster inside another two-piece 3D-printed form I had made (we had to use a heat-gun to get the PLA printed form off of that plaster). I smoothed the surface on the wheel using a metal rib and trimming tool. Then I stretched a rubber band around the first step at the bottom (because the rail was a little lose-fitting), it fit perfectly and clamped tightly in place. To cast a plaster jigger mold it is just a matter of soaping the plaster model and the inside of the rail. One improvement this needs: I 3D printed ring that drops down to the shoulder to force it perfectly round.

A 3D-printed pour spout on a mug cast-jigger mold

I prepare to attach these by simply touching them to the top of the slip (it is sticky and coats the underside evenly). Then it is just a matter of setting it in place and and it glues down in seconds. I make these a little larger diameter than the top of the opening in the plaster mold (e.g. 2mm), producing a small overhang on the cast piece (this one has 0.8mm thick walls and prints quickly). During the time in the mold, the clay slurry creates a thickness against the plaster walls that also extends upward above the top (inside the spout). Shortly after pour-out I put these into the cuphead on the jigger wheel and make a cut and lift the spout away. This leaves an over-hang and over-height that enable finishing the rim using the jigger template.

Cuphead for Shimpo jigger wheel

This is machined out of aluminum. We also have drawings of a 3D-printable shell-mold for making molds that drop into this. And methodology for printing the outside contour of pieces to be jiggered.

Links

URLs	https://insight-live.com/insight/recipes.php?OpenFile=PX1xXqG8su Drawing of shell with flange for making a jigger mold 3D print this and invert it over a form for the outside contour of a mug and pour working plaster jigger molds. This link enters your Insight-live account so you need to be logged in.
Projects	Project to Document a Shimpo Jiggering Attachment Make your own jiggering attachment for your potter's wheel. Here are the plans and lots of help to get you going with molds and techniques.

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