Rapid Prototyping

Question 1

Types of material removal rapid prototyping

Answer 1

Primarily milling and drilling using CNC machine.

Question 2

Materials used in material addition rapid propotyping

Answer 2

Liquid monomers that are curated layer by layer

Powders that are aggregated and bonded layer by layer

Solid sheets that are laminated

Question 3

How to prepare the control instructions for rapid prototyping

Answer 3

Geometric modeling- cad

Tessellationof the geometric models concert to appropriate format

Slicing of the model into layers

Question 4

Stereolithography

Answer 4

Fabricating a solid plastic part out of photosensitive liquid polymer using a directed laser bean to solidify the polymer. There’s a platform that moves vertically in photosensitive polymer and laser beam that can move in x-y direction solid layer of plastic formed that adheres to plastic then platform lowered.

Question 5

Fused deposition modeling

Answer 5

Filament of polymer is extruded onto the existing part surface from a work head to complete each layer.workhead moves on x-y plane then moves up one layer

Question 6

Challenges asosiatednto FDM

Answer 6

Can’t do overhang
Surface sighs
Feature resolution

Question 7

Polymer jetting

Answer 7

Uses photocurablen polymer inks and jets them out of thousand of small nozzles as high accuracy. After each layer is deposited uv lamp is passed over it. Uses wax based or water soluble supports. Allows for blending of material and colours but more epensive

Question 8

Selective laser sintering

Answer 8

Uses moving laser beam or singer heat fusible powders in areas corresponding to cad model layer at a time. After each layer a new layer of loose powder is spread over by a recoater. Powders are preheated to just elow melting point to reduce distortion and facilitate bonds. Excessive powder recovered in overflow chamber

Question 9

Direct metal laser sintering

Answer 9

Higher power lasers are used and the process chamber is often an inert atmosphere to prevent oxidation of molten metal. Laser melts metallic powder on platform layer by layer. Part must be welder to plate as under high stresses that could warp the component. Creates parts with superior mechanical properties due to base material