MEC2040
Rapid Prototyping
SLA
SLS
FDM
LOM
CNC machining
What it
stands for
Stereolithography
(apparatus)
Selective Laser
Sintering
Fused Deposition
Modeling
Laminated Object
Manufacturing
Computer
Numerically
Controlled
How it works
Laser scans and
solidifies layers of
liquid plastic
Laser scans and
solidifies layers of
powdered material
Laser cuts out
layers of gluebacked paper
Cutting Tool moves
to series of
coordinate points
How the
parts are
fixtured in
fabrication
Thin walled
breakaway structure
Remaining
Unsintered powder
on each layer-
Cross-hatched
paper breaks away
outside of model
Vises, clamps,
screws, epoxy
nests, machined
shapes etc.
Materials
Unique, brittle, messy
and expensive
Metals, ceramics
and thermoplastics
Cost
High
Medium to high
Double barreled
‘glue gun’ lays down
layers of molten
material
Second barrel
shoots non-bonding
material to fill spaces
under part
Common
thermoplastics and
wax
Dirt
Accuracy
Excellent
Fair
Fair
Support for
molding
Quickcast process
makes easy burn
honeycomb interior
Surface
finish
Good - small steps
sand smooth
No casting masters
but none necessary
for direct mold
fabrication
Poor - granular
steps tough to fix
Pros
Fine detail
Strong materials
Cons
Requires ‘lab’ set-up
Poor on fine detail
Paper (wood)
Some plastic and
metal laminates
Low
Fair/Poor in z
Absorbs moisture if
not sealed.
Easy melt wax
casting masters
No special way of
making masters
Poor - tough to fill
smooth
Compact machine,
Strong ‘fibered’ parts
Good - small steps
sand smooth
Fast for big parts,
strong like wood
Can’t build hollow
parts
Poor on detail
P Johnson referencing www.efunda.com
Just about
anything
Medium to High
Good and
potentially the best
Casting masters
for undercut molds
are difficult
Outstanding
Many – see above,
production speeds
Slow programming