MECH 3503 - Rapid Prototyping

• 1. material removal
• 2. material addition

• 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

• geometric model
• tessalation (.stl)
• slice model into layers

• 1. liquid based
• 2. solid based
• 3. powder based

• 1. stereolithography
• 2. solid ground curing
• 3. droplet deposition manufacturing

photosensitive liquid polymer in a bath and a directed laser beam solidifies the polymer 

each layer is 0.076 - 0.5 mm 

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

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

• laminated object manufacturing
• fused deposition modelling

• a solid based rp
• sheet stock is rolled over a paltform where a part cross section is made and a laser cuts it out 

a type of solid based rp

3d printing

• nozzle melts long filament of polymer 
• workhead controlled in xy plane and moves up in z

• selective laser sintering 
• three dimensional printing

layer of loose powder come, laser selectvely sinters, more powder added

3dp

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

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

• 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