MECH 3503 - Rapid Prototyping

  1. two categories of rapid prototyping
    • 1. material removal
    • 2. material addition
  2. starting materials in material addition (4)
    • 1. liquid monomers that are cured layer by layer into solid polymers
    • 2. powdered aggregated and bonded layer by layer
    • 3. solid sheets laminated 
    • 4. phase transition droplet on demand deposition
  3. how to prepare
    • geometric model
    • tessalation (.stl)
    • slice model into layers
  4. types of rapid prorotyping classification based on starting material
    • 1. liquid based
    • 2. solid based
    • 3. powder based
  5. types of liquid based rapid prototyping
    • 1. stereolithography
    • 2. solid ground curing
    • 3. droplet deposition manufacturing
  6. what is stereolithography
    photosensitive liquid polymer in a bath and a directed laser beam solidifies the polymer 

    each layer is 0.076 - 0.5 mm 

    Image Upload 1
  7. what is solid ground curing
    like stereolithography, cures a photosensitive polymer layer by layer, but instead of using a scanning laser beam, the entire layer is exposed to uv source thru a mask

    melted wax poured over to go inside crevices and then milled

    Image Upload 2
  8. what is droplet deposition manufacturing
    a type of liquid based rapid prototyping

    a machine (like a printer, the cool video) have multiple nozzles scanning a surface and depositing uncured liquid photopolymer, which is then automatically cured by a UV light. the platform lowers to deposit more 

    can use phase change waxes
  9. what are types of solid based rp? (2)
    • laminated object manufacturing
    • fused deposition modelling
  10. what is laminated object manufacturing
    • a solid based rp
    • sheet stock is rolled over a paltform where a part cross section is made and a laser cuts it out 

    Image Upload 3
  11. what is fused deposition modelling
    a type of solid based rp

    3d printing

    • nozzle melts long filament of polymer 
    • workhead controlled in xy plane and moves up in z
  12. what are powder based rp (2)
    • selective laser sintering 
    • three dimensional printing
  13. what is selective laser sintering
    layer of loose powder come, laser selectvely sinters, more powder added
  14. what is three dimensonal printing

    • Part is built using an ink-jet printer to eject a solvent
    • material onto successive layers of powders

    Image Upload 4
  15. how can you make tools with rp?
    1. indirect - pattern is created by rp and then pattern used to make tool

    • 2. direct - make tool itself e.g. 3DP to create a die of metal powders followed
    • by sintering and infiltration to complete the die
  16. what are problems with rapid prototyping (2)
    • Part accuracy:
    • ▪ Staircase appearance for a sloping part surface
    • due to layering
    • ▪ Shrinkage and distortion of RP parts
    • ▪ Limited variety of materials in RP
    • ▪ Mechanical performance of the fabricated parts
    • is limited by the materials that must be used in
    • the RP process
Card Set
MECH 3503 - Rapid Prototyping