Week 12. Molding and Casting#

Authors : Jun Kawahara, Kai Naito, Asako Okazaki, Georg Tremmel
Created : 3/1/2019, Last Update: 4/19/2023

Danger

Rico’s Final Project Countdown & Management

Assignments#

Individual Assignments#

design a mold around the stock and tooling that you’ll be using,
mill it (rough cut + three-axis finish cut),
and use it to cast parts
extra credit: use more then two mold parts

Group assignment#

review the safety data sheets for each of your molding and casting materials,
then make and compare test casts with each of them
extra credit: try other molding and casting processes

Learning outcomes#

Design appropriate objects within the limitations of 3 axis machining
Demonstrate workflows used in mould design, construction and casting

Have you answered these questions?#

Linked to the group assignment page and reflected on your individual page what you have learned
Reviewed the safety data sheets for each of your molding and casting materials, then made and compared test casts with each of them
Documented how you designed your 3D mold and created your rough and finish toolpaths for machining, including machine settings
Shown how you made your mold and cast the parts
Described problems and how you fixed them
Included your design files and ‘hero shot’ of the mold and the final object

Timetable

Confirmation of this week’s assignment
Class review
MTM progress review
Group work
Individual work

Agenda#

Individual Assignments#

Learn the three-step casting process for making silicon moulds Yuichi Tamiya 2017, Georg Tremmel 2021

Help

Support Document: Rico’s Mold Making Tutorial in Fusion360

Group Assignment#

SDS#

Ferris® File-A-Wax® Carving & Milling Waxes - Freeman Manufacturing and Supply Company
- SDS for blue wax
Smooth-On Document Library - Technical Bulletins (TB), Safety Data Sheets (SDS)
- MOLD STAR 16 FAST
  - TB / SDS
  - Color: Blue-Green
  - Pot Life: 6 minutes
  - Cure Time: 30 minutes
  - Mix Ratio By Volume: 1A:1B
  - Mix Ratio By Weight: 1A:1B
- SMOOTH-CAST 300
  - TB / SDS
  - Color: White
  - Pot Life: 3 minutes
  - Cure Time: 10 minutes
  - Mix Ratio By Volume: 1A:1B
  - Mix Ratio By Weight: 100A:90B
- SMOOTH-CAST 325
  - TB / SDS
  - Color: Clear Amber
  - Pot Life: 2.5 minutes
  - Cure Time: 10 minutes
  - Mix Ratio By Volume: 1A:1B
  - Mix Ratio By Weight: 115A:100B
- SORTA-CLEAR 37
  - TB / SDS / Food Safe Technical Bulletin
  - Color: Water Clear Translucent
  - Pot Life: 25 minutes
  - Cure Time: 4 hours
  - Mix Ratio By Volume: 1A:1B
  - Mix Ratio By Weight: 1A:1B

Individual assignment#

Material#

Ferris File-A-Wax Blue
Size : 147 x 88 x 37mm (Actual mesurement 実測値)
Manuacturer site

Tools#

⅛inch (3.18 mm) long 4FL SE
⅛inch 2FL BN
1/16inch 2FL BN

Notes on Machining#

Create two types of toolpaths - Rough Cut: a layered path to remove material efficiently - Finish cut: three-dimensional milling like descending a valley and ascending a mountain

Square end: even a square can be made into the three-dimensional path described above for finishing.
Ball end: The cutting edge can go into finer areas than square. When cutting horizontal surfaces, it takes more time than square.
XTRA LONG : Can cut deeper pockets. However, the bite bends, so run-out (shaft shake) is greater. Recommended for this week’s task. Make sure that the shank and collet do not strike the material (especially when trying to dig deeper pockets). For example, taper the walls of the pocket to make room for the shank and collet.