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11. Molding and casting

General Info

Nueval

  • Global evaluation
  • App screenshot -> English

Output devices

  • Parts

  • AVR-1

    • megaTinyCore
      • Arduino Board manager
      • I2C (TWI) support
        • You must be sure to use external pullup resistors on the SDA and SCL lines if the devices you are connecting do not have those on board
        • 10k Ohm x2
        • sample

Assignment

Group assignment:

Note

review the safety data sheets for each of your molding and casting materials, then make and compare test casts with each of them

Individual assignment:

Note

design a mold around the stock and tooling that you’ll be using, mill it (rough cut + (at least) three-axis finish cut), and use it to cast parts

preparation of 3D modeling

  • MDX-15
    • work area: 152.4mm × 101.6mm × 60.5mm
  • Machinable wax
    • size: 152mm x 92mm x 39mm (real size is smaller)
  • Endmill
    • 0.1250” DIA 4FL SE LONG AlTiN 1/8
      • Size: 1/8”=3.175mm
      • OverAll Length: 2-1/4”(2.25”) =57.15mm
    • 0.0625” DIA 2FL SE AlTiN 1/16
      • Size: 1/16” =1.5875mm
      • OverAll Length: 1-1/2”(1.5”) =38.1mm

  • Design to think…

    • XY size: real wax size
      • Final Part size < (wax size - wax_wallx2 - mold_wallx2)
      • distance between bumps凸 & dents凹: tool size > 1.58mm(1/16”) > 0.79mm(1/32”)
    • Z depth
      • tool: 1/16_endmill_lemgth=38.1mm -in_collet_lenght=10mm = 28mm
      • machine: MDX-15_z=60.5mm - Wax_height_39mm = 21.5mm
    • Registration (for alignment)
    • pour spout (lower position)
    • air vent (higher position)
    • part line -> deburring

  • Process

    • 3D modeling
      • Fusion360
    • Tool Path
      • Modela Player4 (Windows)
      • Virtual Modela (Windows)
      • Rough cut (1/8”)
      • Finish cut(1/16”)
    • cast silicone molds from wax
    • cast final part from silicone molds

TODO: Group assignment

review the safety data sheets for each of your molding and casting materials,

materials

make and compare test casts with each of them

  • test cast
  • safety
    • ventilation
    • protection
      • glass
      • groves
    • disposal
      • finish chemicals reaction before dispose -> heat
      • dispose cups and Stir bars directly into bin
      • change groves
        • do not touch any uncovered place, chair, desk…

TODO: Individual assignment

design a mold around the stock and tooling that you’ll be using,

  • negative/positive

    • 3D modeling process
      • sample
      • design final part (positive)
      • design molds to make final part (negative)
      • design wax to make molds (positive)
    • casting process
      • pour liquid silicone rubber into wax to cast molds (negative)
      • pour liquid resin into molds to cast final part (positive)

  • Fusion360

    • Final_part
      • model as any way
    • Silicon_mold
      • model Silicon_block
      • combine > cut
        • Silicone_block - final part = Silicon_mold
    • Wax
      • model Wax_block
      • combine > cut
        • Wax_block - Silicone_mold
      • add
        • Pour Spout
        • Air vent
        • Registration key

mill it (rough cut + (at least) three-axis finish cut), and use it to cast parts

ref.Roland Modela Player4

Assessment

Moulding and Casting

  • I want to only make a wax mould, and cast something in it. Is that acceptable?

    • Answer: Only after you learn and go through the 3 step process. To break the rules, you have to master the rules.

  • Can I 3D print the mold? Can I do a lasercut?

    • Answer: No, for this assignment you must mill the mould using a CNC milling machine. After fulfilling the requirements, please go ahead and experiment other techniques for fabricating moulds.
Last update: April 26, 2021