Mold Design

     For this exercise, I decided to try making a two part mold for wavy dish that could be used for beading, with smooth grooves that would help line up and separate different coloured beads.

 

    I started by making a profile with the wavy grooves, top side using handle based bezier curves, and the bottom side using straight lines and then used the Chamfer Corners command to the round the sharp corners, making sure the top and bottom side don't have any steep angles. I connected the top and bottom, with a line and split it to add the draft angle to the edge of the dish. 

     Next I drew the shape of the plate, using the polygon tool to make a pentagon, then chamfered the corners to create a softer shape that I liked. I scaled up and lined my profile curve up with the pentagon, and used the Rail Revolve command, then the Cap command to fill in the centre so the solid became a closed surface.

👆 Bottom and top view of the closed surface👆

 

 

    Next I made another pentagon and chamfered the corners for the profile of the mold. I extruded it once on the positive Z axis by 20mm, used the Taper command to taper it inward, giving it a draft angle to easy removal from the carved foam. Then I used the Mirror command to make the other half. After that, I brought the wavy plate into it and used the Boolean Difference command to create the first cavity.

    Next I made the keys using the Truncated Cone command, then used another pentagon to create guide points at the midpoints of each side of the mold, and placed copies of the key at each point. I then made a sprue from a cylinder and a truncated cone, with the end intersecting the cavity of the mold, scaling them to make sure that the end face of the sprue lies inside the cavity and doesn't intersect with the wall. Lastly, I made another cylinder about 5mm wide to cut holes for air to escape, as the sprue width would probably be too narrow to let out air while pouring the slip. Once I felt the placements were good, I united the keys with the bottom half, then used the bottom to cut the top half using boolean difference, and finally used boolean difference to cut the sprue and air outlets from both halves. 

    Once everything looked good, I followed up by adding a 2.5mm bevel to the outer edge where the two halves meet, just to further help with removing it from the foam.Here are the two halves, open sides up, with the bounding box of the foam block for reference.

As a final, extra step, I lined up the halves with the bounding box, and then made a solid box using the guidlines, and cut the mold from the box with boolean difference, seeing how