Environmentally Responsible Design & Manufacturing (MEEM 4685/5685)Dept. of Mechanical Engineering - Engineering MechanicsMichigan Technological University© John W. Sutherland
Lecture #13
ERDM
Prof. John W. Sutherland
Feb. 9, 2004
Environmentally Responsible Design & Manufacturing (MEEM 4685/5685)Dept. of Mechanical Engineering - Engineering MechanicsMichigan Technological University© John W. Sutherland
The Product Design Process
• Concept Design - System Design
• Module definition - Assemblies
• Detailed Product Design - Material Type & Features
• Detailed Product Design - Dimensions & Tolerances
• Prototyping and Testing
Environmentally Responsible Design & Manufacturing (MEEM 4685/5685)Dept. of Mechanical Engineering - Engineering MechanicsMichigan Technological University© John W. Sutherland
So far....
• Want to understand how the characteristics of aproduct design impact the environment
- Material selection issuesMining & Metals processing, Plastics
- Concept designQFD proposed as one way to “hear the voices”:customer and environment
Next: How does product design geometry influencerecycling?
Environmentally Responsible Design & Manufacturing (MEEM 4685/5685)Dept. of Mechanical Engineering - Engineering MechanicsMichigan Technological University© John W. Sutherland
Product Life Cycle
ProductReuse
Remanufacturing
Recycling
Nature
MaterialDisposalRaw Materials/
Energy Acquisition
MaterialRefinement
ProductCreation
Product Usage
ProductDisposal
Environmentally Responsible Design & Manufacturing (MEEM 4685/5685)Dept. of Mechanical Engineering - Engineering MechanicsMichigan Technological University© John W. Sutherland
Reuse?
• What promotes it?
• What discourages it?
Environmentally Responsible Design & Manufacturing (MEEM 4685/5685)Dept. of Mechanical Engineering - Engineering MechanicsMichigan Technological University© John W. Sutherland
Remanufacturing?
• What promotes it?
• What discourages it?
Environmentally Responsible Design & Manufacturing (MEEM 4685/5685)Dept. of Mechanical Engineering - Engineering MechanicsMichigan Technological University© John W. Sutherland
Recycling?
• What promotes it?
• What discourages it?
Environmentally Responsible Design & Manufacturing (MEEM 4685/5685)Dept. of Mechanical Engineering - Engineering MechanicsMichigan Technological University© John W. Sutherland
Geometric Features
Focus on a single part (element of a larger product)
• Holes
• Slots
• Threads
• Contours
In general, the size and shape of a product.How do these features influence the three R’s??
Environmentally Responsible Design & Manufacturing (MEEM 4685/5685)Dept. of Mechanical Engineering - Engineering MechanicsMichigan Technological University© John W. Sutherland
Role of Geometric Features
• Large parts vs. small parts
• Large surface area vs. small
• Complex vs. simple
• Presence of mating / sliding surfaces
• Sections / features that experience high stress
Environmentally Responsible Design & Manufacturing (MEEM 4685/5685)Dept. of Mechanical Engineering - Engineering MechanicsMichigan Technological University© John W. Sutherland
Product Features
Hole
Chamfer
Bore
Slot
Boss
Bend
Groove Threads
Environmentally Responsible Design & Manufacturing (MEEM 4685/5685)Dept. of Mechanical Engineering - Engineering MechanicsMichigan Technological University© John W. Sutherland
Opitz Classification Code
LD
LD
LD
LD
LD
< 0.5
> 3
< 2
0.5 < < 3
WithDeviation
> 2 WithDeviation
Specific
Specific
0
1
2
3
4
5
6
7
8
9
Rot
atio
nalC
ompo
nent
s
AB
AC
< 3, > 4
AB
< 3
AB
AC
< 3, < 4
External Shape,external shape
elements
Internal Shape,internal shape
elements
PlaneSurface
Machining
Auxiliary holesand
Gear Teeth
OverallShape
OverallShape
OverallShape
OverallShape
RotationalMachining
Internal andExternal Shape
Elements
PlaneSurface
Machining
PlaneSurface
Machining
PrincipalBores
Auxiliary holes,Gear teeth,Forming
Auxiliary holes,Gear teeth,Forming
Dim
ensi
onM
ater
ial
Initi
atio
nof
Raw
Mat
eria
lsA
ccur
acy
1st DigitComponent
Class
2nd DigitOverall or
Main Shape
3rd DigitRotational
SurfaceMachining
4th DigitPlane
SurfaceMachining
5th DigitAuxiliary holes
Gear TeethForming
1st 2nd 3rd 4thDigit
Non
-rot
atio
nalC
omp.
Environmentally Responsible Design & Manufacturing (MEEM 4685/5685)Dept. of Mechanical Engineering - Engineering MechanicsMichigan Technological University© John W. Sutherland
MDSI Code (Manf. Data Sys., Inc.)
Environmentally Responsible Design & Manufacturing (MEEM 4685/5685)Dept. of Mechanical Engineering - Engineering MechanicsMichigan Technological University© John W. Sutherland
D-Class CodeStr. Cylder (A,B)
Cont. Tapered (C)Changing
Round O.D.Curved/
Spherical (D)
w/ straight (E)Combo
w/o straight (F)Solid
ShapesGearlike (G)
Round w/devations Reg. Dev. (H)
Irreg. Dev. (J)Rotational
Roundw/ bent
centerline (K)Drawn/
Basic Spun (L)Shape
Column Str. (M)
Non- Sheet Form (N)Rotational
Box-Like (P)
Unnamed (Q-Z)
Environmentally Responsible Design & Manufacturing (MEEM 4685/5685)Dept. of Mechanical Engineering - Engineering MechanicsMichigan Technological University© John W. Sutherland
Post-use Alternatives
Original Part
New Parts New Part
Excess Excess
New Part
Original Part
New Part
New PartsExcess
xcess
Excess
Excess
Excess
Environmentally Responsible Design & Manufacturing (MEEM 4685/5685)Dept. of Mechanical Engineering - Engineering MechanicsMichigan Technological University© John W. Sutherland
Washing MachinePercentage
DCLASS of TotalWashing Machine Category PartsPart Distribution
Str. Cylder (A,B) 26.38%26.38%
Cont. Tapered (C) 1.97%Changing
Round O.D.
31.10% 3.15% Curved/Spherical (D) 1.18%
w/ straight (E) 1.57%Combo1.57% w/o straight (F) 0%
SolidShapes61.41% Gearlike (G) 1.18%
Round w/devations Reg. Dev. (H) 18.11%
19.29%Irreg. Dev. (J) 0%
Rotational61.41% Round
w/ bentcenterline (K) 11.02%
Drawn/ 11.02%Basic Spun (L) 0%Shape 0%100%
Column Str. (M) 2.76%
Non- Sheet Form (N) 18.11%Rotational
38.59% Box-Like (P) 9.06%
Unnamed (Q-Z) 8.66%
Environmentally Responsible Design & Manufacturing (MEEM 4685/5685)Dept. of Mechanical Engineering - Engineering MechanicsMichigan Technological University© John W. Sutherland
RPI - Reprocessability IndexSystem (Wentland)
Focus on Rotational Parts
ProductNumber of
PartsRotational
Parts %
Washing Mach. 254 61%Cordless Drill 53 60%Automotive Jack 122 80%Electric Drill 79 68%Utility Engine 188 68%
Environmentally Responsible Design & Manufacturing (MEEM 4685/5685)Dept. of Mechanical Engineering - Engineering MechanicsMichigan Technological University© John W. Sutherland
RPI Philosophy
Define metrics that, when small, are more likely resultin product post-use. Metrics for the following
• Part complexity (more complex is bad)
• Part size (smaller parts are bad)
• Removable features (preferred)
• Relative stress level (low stress -- less damage?)
• Amount of mating (moving) contact areas (minimize)
Environmentally Responsible Design & Manufacturing (MEEM 4685/5685)Dept. of Mechanical Engineering - Engineering MechanicsMichigan Technological University© John W. Sutherland
Definition of RPI Terms
R1Volume of Bounding Volume
Part Volume-----------------------------------------------------------------------
VBVV
-----------= =
Projected Volume
Part
Environmentally Responsible Design & Manufacturing (MEEM 4685/5685)Dept. of Mechanical Engineering - Engineering MechanicsMichigan Technological University© John W. Sutherland
RPI Terms - 2R2
Surface AreaSurface Area of Bounding Volume------------------------------------------------------------------------------------ SA
SABV--------------= =
Environmentally Responsible Design & Manufacturing (MEEM 4685/5685)Dept. of Mechanical Engineering - Engineering MechanicsMichigan Technological University© John W. Sutherland
RPI Terms - 3
4 other terms to consider other factors
Want to minimize RPI
RPI calculation linked to AutoCAD
RPI Ri∑=
Environmentally Responsible Design & Manufacturing (MEEM 4685/5685)Dept. of Mechanical Engineering - Engineering MechanicsMichigan Technological University© John W. Sutherland
D-Class Parts
Environmentally Responsible Design & Manufacturing (MEEM 4685/5685)Dept. of Mechanical Engineering - Engineering MechanicsMichigan Technological University© John W. Sutherland
Washing Machine Parts
Environmentally Responsible Design & Manufacturing (MEEM 4685/5685)Dept. of Mechanical Engineering - Engineering MechanicsMichigan Technological University© John W. Sutherland
Washing Machine Parts - 2
Environmentally Responsible Design & Manufacturing (MEEM 4685/5685)Dept. of Mechanical Engineering - Engineering MechanicsMichigan Technological University© John W. Sutherland
Another Example