1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
MEGR 3232
Plastics Design –
Exam 3 Review Notes
Additive Manufacturing • Mold Design
• Draft Angles • Ribs & Gussets • Bosses
• Wall Thickness • Hinges
, Exam 3 Prep :
Topic : Plastic Part Design for moldability
From CAD Data
Manufacturing) ( :
Direc t Digital to working models
·
DDM : is about making real physical parts directly
f ro m CAD files using digital machines (3D printers)
陈
No molds , no tooling you design its the machine builds it
Core idea : CAD Machine Finished part
1 physical parts ,
from CAD , using digital machines)
· These digital manufacturing methods a re already used
in re al industries (not just prototypes) :
FDM (Fused Deposition melts plastic filament's
Modeling ) : Prints layer by layer
uses liquid resin cured
SLA(Sterolithography ) :
laser
by a
SLS (Selective Laser uses a laser to fuse
Sintering) : powdered plastic
same idea
DMLS (Direct Metal Laser as SLS but
Sintering) : ~ / metal powder
3D printing already mainstream
core idea : 、
&
. used in real products
Other names : Rapid manufacturing , Rapid Tooling ,
Free Form Fabrication ,
Additive manufacturing
(DDM has many names , but they all
mean the s am e thing
building parts layer-by-layer instead of
butting or molding them
Why it matters :
This method lets you :
1 . M a ke shapes that we re impossible before
2 . create new types of products
.
3 Changes h ow engineers design things
4 .
Changes n ow companies manu fac ture things
new
Additive ne √
idea : 르
possibilities
+ design
core
manufacturing freedom
, of
Benefits using digital/additive manufacturing
instead of traditional methods :
key advantages :
1 . Faster time to m a r ke t (no waiting for molds
.
2 star t production as soon as design is ready
.
3 shor ter turnaround for parts
4
. Lower upfront cost (no expensive tooling)
build (even complex shapes (
5
. Can whatever you model
.
6 Easy customization (every part can be different (
7
. Free iterations (Changing design costs nothing (
core idea : faster , cheaper to st ar t ,
m o re flexible , "
Per fect for custom or complex parts
Why a good choice for smaller production :
is
·
DDM/ Additive manufacturing cost-effective
for low production volumes
Traditional manufacturing
• Traditional manufacturing (like injection L like injection molding (
molding) has high upfront tooling costs.
migh uis froun
• Additive manufacturing has almost no setup LostS
cost, so the cost per part stays flat even at low
quantities. DDM/ Additive
manufacturing
• This makes it ideal for small batches, custom
parts, prototypes, and specialty items. ideal for
almost NO -mall
Setup costs batches
Lustom parts
core idea : Low volume DDM/ Additive is cheaper
High vol u m e traditional is cheaper
Why a bad choice
·
DDM/ Additive manufacturing has weakness :
1) Anisotropic =
parts a re we a ke r in one direction
- t h e re built in layers
2 Layer l i n e s Sur faces a re n o t perfectly s m oot h
2 some methods s h ow this
m o re strongly than others)
core idea : layering creates
we a k spots ; rough sur faces
, Video: “Anisotropic” — Key points only
(https://www.youtube.com/watch?v=xn_eVKm_2hM)
• 3D printed parts have different strength depending on direction. in
Strongest plane
in
• Strongest in-plane, weakest between layers. weakest layers
• Important for load bearing parts and engineering design.
Slide: “Why not?” – Cost per part graph
Simple meaning:
Additive manufacturing is not ideal for high volume production.
Why: Low vo l u m e >
-
additive
• Traditional methods get cheaper per part as volume increases. cmeaper
• Additive manufacturing stays flat — no economies of scale. volume - >
High
• After a certain volume, traditional manufacturing becomes much cheaper. traditional
cheaper
Core idea:
High volume = additive is too expensive.
Slide: “Davis Tech – good comparison”
Simple meaning:
These videos compare printing vs molding and show when each method makes sense.
Video 1 — Key points 3D printing :
(https://www.youtube.com/watch?v=-VUXKuny3p0) for
-good
customization ,
• Shows how 3D printing works step by step.
low volume ,
• Highlights speed, flexibility, and low setup cost. tast/tree
iterations
• Good for custom parts and small batches.
-
s m all
Video 2 — Key points batches
custom parts
(https://www.youtube.com/watch?v=ffRszebaO7U)
• Compares printing to traditional manufacturing. Injection
molding :
• Shows that molding is faster and cheaper for large quantities.
• Reinforces the “low volume vs high volume” rule.
goodfor
-
Slant 3D – mold or print? quantities
mass
(https://www.youtube.com/watch?v=t0mCGcM2w7g) production
• Explains how companies decide between 3D printing and injection molding.
• Printing wins for customization, low volume, and fast iteration.
• Molding wins for mass production.
‑ ‑ ‑ ‑‑
2
3
4
5
6
7
8
9
10
11
12
13
14
15
MEGR 3232
Plastics Design –
Exam 3 Review Notes
Additive Manufacturing • Mold Design
• Draft Angles • Ribs & Gussets • Bosses
• Wall Thickness • Hinges
, Exam 3 Prep :
Topic : Plastic Part Design for moldability
From CAD Data
Manufacturing) ( :
Direc t Digital to working models
·
DDM : is about making real physical parts directly
f ro m CAD files using digital machines (3D printers)
陈
No molds , no tooling you design its the machine builds it
Core idea : CAD Machine Finished part
1 physical parts ,
from CAD , using digital machines)
· These digital manufacturing methods a re already used
in re al industries (not just prototypes) :
FDM (Fused Deposition melts plastic filament's
Modeling ) : Prints layer by layer
uses liquid resin cured
SLA(Sterolithography ) :
laser
by a
SLS (Selective Laser uses a laser to fuse
Sintering) : powdered plastic
same idea
DMLS (Direct Metal Laser as SLS but
Sintering) : ~ / metal powder
3D printing already mainstream
core idea : 、
&
. used in real products
Other names : Rapid manufacturing , Rapid Tooling ,
Free Form Fabrication ,
Additive manufacturing
(DDM has many names , but they all
mean the s am e thing
building parts layer-by-layer instead of
butting or molding them
Why it matters :
This method lets you :
1 . M a ke shapes that we re impossible before
2 . create new types of products
.
3 Changes h ow engineers design things
4 .
Changes n ow companies manu fac ture things
new
Additive ne √
idea : 르
possibilities
+ design
core
manufacturing freedom
, of
Benefits using digital/additive manufacturing
instead of traditional methods :
key advantages :
1 . Faster time to m a r ke t (no waiting for molds
.
2 star t production as soon as design is ready
.
3 shor ter turnaround for parts
4
. Lower upfront cost (no expensive tooling)
build (even complex shapes (
5
. Can whatever you model
.
6 Easy customization (every part can be different (
7
. Free iterations (Changing design costs nothing (
core idea : faster , cheaper to st ar t ,
m o re flexible , "
Per fect for custom or complex parts
Why a good choice for smaller production :
is
·
DDM/ Additive manufacturing cost-effective
for low production volumes
Traditional manufacturing
• Traditional manufacturing (like injection L like injection molding (
molding) has high upfront tooling costs.
migh uis froun
• Additive manufacturing has almost no setup LostS
cost, so the cost per part stays flat even at low
quantities. DDM/ Additive
manufacturing
• This makes it ideal for small batches, custom
parts, prototypes, and specialty items. ideal for
almost NO -mall
Setup costs batches
Lustom parts
core idea : Low volume DDM/ Additive is cheaper
High vol u m e traditional is cheaper
Why a bad choice
·
DDM/ Additive manufacturing has weakness :
1) Anisotropic =
parts a re we a ke r in one direction
- t h e re built in layers
2 Layer l i n e s Sur faces a re n o t perfectly s m oot h
2 some methods s h ow this
m o re strongly than others)
core idea : layering creates
we a k spots ; rough sur faces
, Video: “Anisotropic” — Key points only
(https://www.youtube.com/watch?v=xn_eVKm_2hM)
• 3D printed parts have different strength depending on direction. in
Strongest plane
in
• Strongest in-plane, weakest between layers. weakest layers
• Important for load bearing parts and engineering design.
Slide: “Why not?” – Cost per part graph
Simple meaning:
Additive manufacturing is not ideal for high volume production.
Why: Low vo l u m e >
-
additive
• Traditional methods get cheaper per part as volume increases. cmeaper
• Additive manufacturing stays flat — no economies of scale. volume - >
High
• After a certain volume, traditional manufacturing becomes much cheaper. traditional
cheaper
Core idea:
High volume = additive is too expensive.
Slide: “Davis Tech – good comparison”
Simple meaning:
These videos compare printing vs molding and show when each method makes sense.
Video 1 — Key points 3D printing :
(https://www.youtube.com/watch?v=-VUXKuny3p0) for
-good
customization ,
• Shows how 3D printing works step by step.
low volume ,
• Highlights speed, flexibility, and low setup cost. tast/tree
iterations
• Good for custom parts and small batches.
-
s m all
Video 2 — Key points batches
custom parts
(https://www.youtube.com/watch?v=ffRszebaO7U)
• Compares printing to traditional manufacturing. Injection
molding :
• Shows that molding is faster and cheaper for large quantities.
• Reinforces the “low volume vs high volume” rule.
goodfor
-
Slant 3D – mold or print? quantities
mass
(https://www.youtube.com/watch?v=t0mCGcM2w7g) production
• Explains how companies decide between 3D printing and injection molding.
• Printing wins for customization, low volume, and fast iteration.
• Molding wins for mass production.
‑ ‑ ‑ ‑‑
