Rapid Prototyping

1
Rapid Prototyping

• An Introduction to Rapid Prototyping Using JP
  System 5
• Windows 95/NT

2
Objectives

• Exposure to rapid prototyping
• Understanding various rapid prototyping
  technologies
• Hands-on experience in rapid prototyping

3
Objectives

• Use of 3D and solid modeling
• Promote integration and concurrent manufacture
• Hands-on exposure to rapid prototyping
• Understand prototyping work flow

4
JP System 5

• Instructional tool for teaching rapid prototyping
• Software for slicing computer models
• Hardware for converting computer slices to a
  prototype

5
Rapid Prototyping

• Enhanced (automated) method for fabrication of a
  physical model or prototype from a
  three-dimensional
• (3-D) CAD file.

6
Why Rapid Prototyping?

• Check feasibility of design concept
• Conduct tests/evaluation
• Assess the fit of complex mechanisms
• Promote concurrent product development
• Cost estimation

7
Why Rapid Prototyping?

• Make molds for castings
• Use as master for silicon and epoxy molds
• Prepare tooling
• Source Manufacturing Engineering Services -
  Alberta Research Council

8
Rapid Prototyping ...

• In late '70's, Charles Hull begins work with
  selective curing of photopolymers (inks).
• Patent awarded for stereolithography in 1986.
• Machine introduced at Autofact in 1987.
• In 1988, SLA-1introduced by 3D Systems.

9
Fabrication Technologies

• Subtractive
• Additive
• Compressive

10
RP - Layer Additive Process

• Build prototype using layers where the "positive"
  portion of the layer is selectively added.

11
RP - Layer Subtractive Process

• Builds prototype using layers in which the
  "negative" portion of the layer has been
  selectively removed.

12
3D Models

• A solid model
• A stereolithography (STL) file

13
Integration and Concurrence
Rapid Prototyping
Computer-Aided Manufacturing
Documentation
Model
Production Drawings
Engineering Analysis
14
Costs

• Type Machine Material Hourly
• Stereo gt100,000 500/gal. 100
• LOM 100,000 1.00/cu. in. 75
• Fused deposition 100,000 10-20/part 75
• Sintering 375,000 20/part 100
• JP System 5 lt7000 .70/cu. in. 15
• Source Thomas, et. al. Shapemaker I An
  Inexpensive Introduction to Rapid Prototyping.

15
JP System 5 Overview

• Create a solid model or import a stereo file.
• Load the model or stereo file into the JP System
  5.
• Orient the model to prepare for slicing.

16
JP System 5 Overview

• Slice model into a series of cross sections.
• Prepare a layout of slices in preparation for
  cutting.
• Cut slices on a series of adhesive sheets.

17
JP System 5 Overview

• Align sheets on registration system.
• Remove backing material.
• Cut sections from sheets and assemble.
• Finish coat.

18
JP System 5 Components

• Part
• Sliced Part
• Single Slice

19
JP System 5 Components

• Sheet
• Sections
• Subparts

20
JP System 5 Components

• Inverted Sections and Subparts
• Cutter
• Registration Board

21
Starting JP System 5

• Double click the SILVERSCREEN shortcut on
  desktop.
• Select TOOLS EXECUTE.
• Select SYS5, then OK.

22
JP System 5
23
Configuring JP System 5

• CONFIGURE Menu
• JP System 5
• Materials available

24
JP System 5

• Board
• Physical paper margins
• Mask enclosure
• Post diameter
• Number of cuts

25
Materials Available

• New item
• Edit selection
• Remove selection
• Set as default

26
CAD Models

• Wireframe
• Surface
• Solid

27
3D Models

• A solid model
• Stereolithography (.STL) file

28
Solid Model

• A model that completely encloses a volume of
  space.

29
Stereolithography File

• CAD data can be converted to the
  Stereolithography (.STL) file format.
• The .STL file is an industry standard interface.
• Developed by the Albert Consulting Group for the
  3D Systems, Inc., StereoLithography Apparatus
  (SLA).

30
Stereolithography File

• Consists of triangles that describe the shape of
  a closed model.
• Faceted surface must be completely bound.
• Many CAD packages export files in the .STL format.

31
Design Considerations

• The design of the model has a bearing on both its
  fabrication and prototyping.
• Design for Manufacture

32
File Menu

• SilverScreen Drawing
• STL File
• Slice File

33
View Menu

• Model
• Sheets (after slicing)
• Information
• Hidden

34
Viewing a Model
35
Hides
36
Setup of Model

• Orientation of model
• Rotate model
• Setup gt Rotate
• Size of model
• Scale model
• Setup gt Scale absolute
• Setup gt Scale relative

37
Orientation

• Properly orient the part in preparation for the
  slicing operation.

38
Orientation for Slicing
39
Some Factors in Prototyping

• Many parts built with a rapid prototyping system
  require some form of support structure.

40
Some Factors in Prototyping

• Unsupported overhangs
• JP-5 rotates part or inverts build

41
Some Factors in Prototyping

• Size of model
• build envelope
• JP-5 provides scaling
• height relative to base
• JP-5 uses subparts
• Wall thickness

42
Some Factors in Prototyping

• JP-5 changes orientation
• JP-5 moves slices

43
Some Factors in Prototyping

• Parts that do not have a stable surface upon
  which to build
• JP-5 divides part

44
Slicing

• Software slices the model into a series of cross
  sections.

45
Setup Slice

• Slice Extent
• Full
• Partial
• Material
• Board

46
Slice Information
47
Layout

• Major registration
• Minor registration
• Sheet number
• Slice
• Non-slice area
• Sections
• Section separators
• Alignment
• New subpart
• Slice enclosure

48
Align Sections

• Look for unsupported slices on the sections

49
Align Sections
50
Create Subparts

• If necessary, create subparts.

51
Align Subparts

• Place sections in appropriate subpart (if more
  than one subpart).

52
Orient Sections

• Invert build direction

53
Enclose Slices
54
Enclose Slices

• Prevents a slice area from sticking to a
  non-slice area.
• Sheet 1 does not have enclosures.
• Sheets 2 3 are automatically enclosed.
• You may enclose all slices.

55
Enclose Slices

• End of section

56
Plot Menu

• Cut Sheets
• Setup
• Test Plotter

57
Test Plotter

• Registration Distances
• Rectilinear Correction

58
Print Menu

• Setup
• Model
• Sections
• Sheets

59
Cutting

• Software converts the slices to an HPGL plot file
  format which is sent to a sign making plotter.

60
Material

• paper
• foam
• vinyl

61
Voids
62
Registration System

• The sheets are layered by aligning the
  registration cuts made in the cutting material
• Registration cuts

63
Registration Board

• Sheets positioned on registration board.

64
Adhesive

• To start, an adhesive is sprayed on the first
  sheet.

65
Removing Backing

• The support back is removed exposing the adhesive
  layer. Each subsequent sheet adheres to the
  exposed adhesive surfaces of the previous sheet.

66
Sections

• Sections formed by the nesting operation are cut
  and assembled.

67
Finish Coat

• The coating seals the adhesive surfaces and,
  depending on the coating material, provides
  additional rigidity to the model.

68
Patterns
69
Patterns

• Casting features
• part of model

70
Casting Pattern
71
Convert to Mold
72
Mold