Skip to content
Snippets Groups Projects
Select Git revision
  • master default protected
  • save-for-new-template
2 results
Blame Permalink
Molding & Casting.md 4.83 KiB

Molding & Casting

I made a dodecahedron in rhino and then made it's molds.

###Process

First made a pentagon, then rotated it along its side at an angle of 116.565. Polar array on all 5 sides. Mirrored horizontally. Oriented both pieces to match. Put it in a bounding box. Extended the middle curves to cut the box into two. I also sweeped a square along the edges for finishing, added on one part of mold and subtracted from the other. Added pipes for pouring in and vent. Made another box of 146x88x36mm, and boolean differenced the previous ones.

Toolpaths

I used FabModules to make the roughing and finishing toolpaths.

First I saved the mold as .stl and then in FabModules...

  • Input stl file
  • Set units/in as 25.4
  • Dpi 500
  • Calculate height map
  • Output rml (to use Roland)
  • Machine MDX-20
  • Speed 20 mm/s
  • x0, y0, z0 = 0,0,0
  • z jog = 12 mm
  • xhome, yhome, zhome = 0,0,0
  • Process wax rough cut 1/8 for roughing, wax finish cut 1/8 for finishing
  • Direction climb for roughing, conventional for finishing
  • Offset overlap 50% for roughing, 90% for finishing
  • Tool diameter 3.175
  • Type: flat end for roughing, ball end for finishing
  • Calculate roughing and save
  • Calculate finishing with above settings and save

Here is a gif that shows process for roughing toolpath calculation

This is how the final roughing toolpaths look:

Here is a gif that shows the difference for finishing toolpath calculation

This is how the final finishing toolpaths look like:

Milling

Will do this step when I'm back in the lab.

Casting

Will do this step when I'm back in the lab.

Files

Home trials

Out of the things I had at home, I chose a wooden spoon to cast in chocolate. Here is the process:

Gathering ingredients:

Wooden spoon - object to cast
Gelatine, water and honey - to make a solution to cast the spoon
Ceramic container - to pour in the solution and fit in the spoon
Hand mixer, weight scale, stirers, measuring cup and other containers to mix stuff
Chocolate and butter - mix to make the final cast

In a measuring cup, I first put 20g of gelatin.

Then added 100ml of water.

Next, added 1 tbsp of honey for binding, and mixed it all together using a small hand blender. There were some lumps that stuck to the blender. In hindsight, maybe heating up the mixture would've helped disolve the gelatine better.

I poured the mixture in a flat long container halfway, let it rest for 5 minutes and then put in the wooden spoon and poured in the rest of the mixture. The setting time for the gelatin is 4 hours according to the box instructions. But it started getting thicker within minutes. I taped the top of the wooden spoon to the table so that it would'nt completely drown into the mixture, keeping about 10% outside.

After refrigerating the mixture for 3 hours at 4 degrees, I removed the spoon carefully using a tiny knife to scrape off the edges.

The part under the curve of the spoon hadn't solidified yet, so I put the mold back in the fridge.

It had solidified after about 1 hour.