Multidisciplinary Engineering Senior DesignProject PO6208 – ArcWorks Closure Tube Assembly
Adaptation Preliminary Design Review02/24/2006
Project Sponsor:ARC Works of Monroe County
Team Members:Team Leader George Gooch, Bill Lucas, Chris Donati, Drew Stone-
Briggs, Hui Kim, Mike Hayden, Mike Levis, Jeff Coppola
Team Mentor:
Dr. DeBartolo (ME) and Dr. Marshall (IE)
Acknowledgements:This material is based upon work supported by the National Science Foundation under
Award No. BES-0527358.Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author and do not necessarily reflect the views of the National Science
Foundation.
Presentation Overview Sponsor
Who they are What is their current process
Team Goals How are we going to help ArcWorks Needs, Feasibility, and Concepts
Final Concept What improvements are being made Time, Flow, Material Handling
SD II
ArcWorks
ArcWorks is the vocational division of the Arc of Monroe County
Have been serving individuals with developmental disabilities and their families for over forty years.
Specialize in providing subcontracting manufacturing services
Comprised of over 250 assembly operators
ArcWorks – Closure Tube Assembly (CTA) A process that supports the assembly of a
bent stem closure with a tube attachment
Quantities produced are close to 500,000 units per year
Currently there are 3 process steps The team is dealing primarily with steps 2 and 3
CTA - Components
Finished Closure
Components
Closure (Various Sizes) Adapter Tube
(Various Lengths)
Step 1 – Straw Cutting Process Machine
10 tubes at once are inserted into the top of the automated tube cutter. The machine cycles, cuts the tubes and they drop through into a box.
CTA - Step 2 (Closure/Adaptor Sub-Assembly) Process MachinesClosures are placed in the bottom fixture and Adapters are placed in the top fixture of one of two style manual presses. The presses are cycled to create the Closure / Adapter Sub-assembly.
CTA - Step 3 (Final Assembly Press) Process Machine
Closure / Adapter Sub-Assemblies are placed in the top fixture of the automated press. Tubes are placed in the bottom fixture. The machine is cycled to create the final assembly.
Team’s Task
Lean Development – integration of sub assembly production orders/releases to ensure minimum/maximum quantities are on hand and flow as required (SD I)
Production Process – improvement of the assembly process, changeover & set-up, ergonomics/safety, and improvement of operator productivity (SD I)
Purchasing Function – ordering of the raw tubing that is cut to length for finished goods assembly (SD II)
Inventory Management – of both raw and cut tubing (SD II)
Needs Assessment
Tools Used
Problem Scope/Definition The mission of this design project team, PO6208, is to redesign a
process that supports the assembly of a bent stem closure with tube attachment called the Closure Tube Assembly. In this design the team hopes to improve the process flow, daily production and worker safety/comfort.
Objective Trees
5 Why’s
Needs Assessment - Outcome
It was decided through evaluations that this machined needed to: Combine assembly steps Decrease the number of moving parts Limit complexity of design Create fixtures that can be used for all product
sizes Use standard components Improve ergonomics Add counters
Feasibility Assessment
Tools Used
REST Resource, Economics, Schedule, Technical
Pugh Method Un-weighted, all attributes equally important
Weighted Comparison Method Looks at attribute importance
REST Method
Compares the chance of success of each idea Rating Scale
1=low chance 5=high chance
Design Idea Avg. Score 1 - 4.10 2 - 4.13 3 - 3.36 4 - 4.10 5 - 3.90 6 - 3.83
Top 3 = Idea 2, 1, 4
Pugh Method
Idea 1 Idea 2 Idea 3 Idea 4 Idea 5 Idea 6
+ 7.00 7.33 6.00 8.50 5.83 4.67
- 2.60 2.60 7.50 1.33 3.17 5.00
0 12.50 12.17 8.17 11.83 12.67 12.00
Compares against a baseline considering all attributes are equally important
Top 3 – Idea 4, 1, 2
Weighted Method
1 2 3 4 5 6
3.854 3.663 2.786 3.779 2.953 3.115
Compares against a baseline considering all attributes are not equally important, but have a weighting Idea
Top 3 – Idea 1, 4, 2
Feasibility Assessment - Outcome Main concerns after feasibility assessment:
Fixtures Closure Holding and Size Variation Tube Holding and Size Variation Adapter Holding
Assembly Alignment Combining Operations Budgeting
Feasibility Assessment - Results Top 3 ideas from feasibility methods
Idea 1 Idea 2 Idea 4
These ideas were the basis for the teams final design.
Final Concept
Step 1 – Part Placement
Step 2 – Press Anti-Tie Down Buttons
Step 3 – Adapter Press
Step 3 – Close Up of Adapter Press
Step 4 – Cylinder Returns
Step 5 – Manual Sub-Assembly Move
Step 6 – Manual Straw Placement
Step 7 – Gripper Press
Step 8 – Dual Cylinder Press
Step 9 – Gripper Return
Step 10 – Dual Cylinder Return
Step 11 – Assembly Removal
Performance Needs
Pneumatic Design Objectives
Improve safety OSHA 1910.217(b)(6)(i)
Limit cost Limit the stroke length of the press cylinders Actuate the press cylinders simultaneously or
independently Control speed and force
Pneumatic Layout
Analysis of Design ( Mechanical ) Design Parameters
FEA Calculations
Assembly Step Force (lbs) Comments
Closure - Adapter 8.75 Max5.40 Average
24mm red closure and clear adapter create max force
Tube - Adapter 3.00 Max2.11 Average
PPCO tube and red adapter create max force
Engineering AnalysisResultant Displacement
Air Cylinder Bracket Support Max Displacement
5.86 x 10-4 inches Location: End of Bracket
Deformation Scale = 3464 Conclusion:
Bracket Support is Rigid
Engineering AnalysisVon Mises Stress Contour Plot
Air Cylinder Bracket Support Max Stress
780 PSI Location: Bracket Connection
Factor Of Safety= 65 Conclusion:
Withstands Applied Forces
Engineering AnalysisFatigue Analysis
Air Cylinder Bracket Support Fa=Fm= 10 lbs Fatigue Strength=Endurance Limit Factor Of Safety w/
Mod Goodman Criterion= 35 Conclusion:
Withstands Infinite Cycles
Fa, Fm
Engineering AnalysisBuckling Analysis
Tube Holder Section 1
Euler Method: Pcr= 11 lbs Factor Of Safety= 2
Section 2 JB Johnson Method: Pcr= 3446 lbs Factor Of Safety= 626
Conclusion: Neither Section will Buckle Possible Improvement:
Limit exposed tube length in Section 1Pcr
2
1
BOM
Improvements - Time
Time Comparison Current Process New Design Process
Step Description Time Step Description Time (sec) (sec) Insert Closure 2 Insert Closure 2 Insert Adapter 2 Insert Adapter 2 Press 2 Press 2 Remove CA 2 Move CA 1.5 Insert Tube 2 Insert Tube 2 Insert Closure 2 Insert CA 2 Insert Adapter 2 Press 4 Press 3 Remove CTA 2 Remove CTA 2 Total Time 18 Total Time 12.5
•Estimated productivity increase of 88 CTA’s per hour
Improvements – Material Handling
Retrieve TubesFrom Hallway(Time – 60)
Cut Tubes(Time – 2)
Place Cut TubesIn Box
(Time – 10)
Move Tube from
Cutter to Pallet(Time - 12)
Move Tube from Pallet to
Final Assembly(Time - 10)
Retrieve Closure
And Adapters From Hallway
(Time - 45)
Transfer Parts from Boxes to
Bins(Time – 12)
Assemble ClosureWith Adapter
(Time – 8)
Place CA In Box
(Time – 2)
Move CAto Pallet
(Time - 12)
Move CA from Pallet to Final
Assembly(Time - 10)
Fill Bins with TubesAnd Closure Assembly
From Box(Time - 20)
Assemble into Final Assembly
(Time – 8)
CurrentManufacturing
Process(All times in seconds)
Box Final Assembly(Time - 5)
27 ft
1 ft
13 ft
8 ft
1 ft
1 ft
1 ft
1 ft
8 ft
12 ft
1 ft
1 ft
10 ft
Transfer Parts from Boxes to
Bins(Time - 12)
1 ft
Tube CuttingOperation 1
Closure Sub-AssemblyOperation 2
Final AssemblyOperation 3
Final Times and DistanceTube Cutting
Time - 106 secDistance - 51 ft.
Closure Sub-AssemblyTime - 99 secDistance - 33 ft.
Final AssemblyTime - 33 secDistance - 2 ft.
Retrieve TubesFrom Hallway
(Time - 60)
Cut Tubes(Time – 2)
Place Cut TubesIn Box
(Time -10)
Move Tube from
Cutter to Pallet(Time - 12)
Move Tube from Pallet to
Final Assembly(Time - 10 )
Retrieve Closure
And Adapters From Hallway
(Time - 45)
Fill Bins with Tubes,Closures, and
Adaptors From Box(Time - 20)
Assemble into Final Assembly
(Time – 8)
FutureManufacturing
Process(All times in seconds)
Box Final Assembly(Time - 5)
27 ft
1 ft
13 ft
8 ft
1 ft
1 ft
1 ft
10 ft
Transfer Parts from Boxes to
Bins(Time - 12)
1 ft
Tube Cutting Process
Operation 1Final
Assembly Operation
2 + 3(Combined)
Final Times and DistanceTube Cutting
Time - 106 secDistance - 51 ft.
Final AssemblyTime - 78 secDistance - 12 ft.
Improvements – New Machine Multiple operations done by one operator
Machine mounted to table for stability
Combines two process steps Eliminates material handling between stations Reduces process time
Improvements – Ergonomic/Safety Ergonomically friendly
Eliminates repeated manual motion Reduces ranges of motion Common plane of motion
Safety Anti-tie-down buttons E-stop
SD II - plans
Investigate Warehouse/Inventory Issues Re-order Points Safety Stock Flow of Material
Desired Outcomes – Manufacturing Area Increased productivity by the ArcWorks team Fewer rejects Higher satisfaction of workers Layout Redesign
Economic Order Quantity -EOQ
Defines the optimal quantity to order that minimizes total variable costs required to order and hold inventory. Q * = optimal order quantity C = cost per order event (not per unit) R = monthly demand of the product P = purchase cost per unit F = holding cost factor; the factor of the purchase cost that is
used as the holding cost (this is usually set at 10-15%, though circumstances can require any setting from 0 to 1)
H = holding cost per unit per month (H = PF)
Questions?
Backup Slides
Following Slides
Straw Cutting Improvements Manual Tube Feeding Concept
Needs Worksheets
Following Slides
Objective Tree – Inventory Management
Inventory Management
Purchasing Warehousing Final Product
Reorder Points Warehousing
Quantity Reorderd
Frequency of Reorder
Order High Volumes
Order Low Volumes
Order Frequently Order Infrequenty
LocationSize of
Inventory
Product LocationWarehouse
locationLow Inventory
QuantityHigh Inventory
Quantity
Quantity Quality
Inspection
BadGood
Objective Tree – Production Process
Production Process
Material Handling Assembly Quality Inspection
Frequency of Handling
Less Manual Process
Determine good products
Determine bad products
High handling frequency
Low Handling Frequency
Failsafes ConsistencyErgonomically
Correct
Take responsibility off of workers
Leads to better Quality
Better worker enviornment
Objective Tree – Fixture Development
Fixture Development
Aid in AssemblyImprove
ErgonomicsIncrease Product
Quality
Produce more parts at one time
Less Manual Machine
Combine multiple processes into one
Lower range of motion
More parts at once to reduce repetition
More like parts with less variance
Go-nogo checkReduce Cycle Time
Easier to use than current process
Quicker Machine Changeover
Less Scrap Parts
5 Why’s
A) Inventory Management
Why do you want us to improve your purchasing and inventory management system? Don’t want to run out of parts.
Why don’t you want to run out of parts? There is a 4 week lead time to
receive the parts from the vendor.
Why is there a 4 week lead time? That’s what the vendor gives us.
Why do you use that vendor? That’s the supplier we have
always used
Why have you always used that supplier? That’s who Nalgene used before
us and we never looked at any other options.
B) Fixture Evaluation
Why do you need new fixturing for your machines? The old ones are not efficient
enough.
Why aren’t they efficient enough for you? The current process is too
manual.
Why is the current process so manual? That’s the way the original
machines were designed.
Why were they designed like that? It met the needs at that time.
Why did it meet the needs then and not now? The demand from the customer
for Closure Tube Assemblies has increased. (This has created a bottleneck in the assembly department.)
Feasibility Worksheets
Following Slides
Weighted Method – How the weightings were achieved
Weighted Method – How the weightings were used
Top 3 Ideas
Following Slides
Original Concepts
Idea 1
Idea 2
Original Concepts
Original Concepts
Idea 4
Concepts from Peer Review
Following Slides
Assembly Process Improvement
Pin Style Automated Press Discussion: Pin tube support
Sliding Adapter Fixture Press Discussion: Closure Interference,
Fixture Alignment, Adapter Orientation
Assembly Process Improvement Two Stage CTA Press
Discussion: CTA Removal, Rotation
CTA Process w/ Magazine Feeder Discussion: Alignment
Feeding Concepts Automated Feeding
Discussion: Cost, Complexity, Durability, Clip Manufacturability
Also… Closure?
Feed Escapement
Tube Adapter
Gantt Chart – SD I
Gantt Chart – SD II