1. P15311: Circuit Board Router (Rev2) Systems Level Design Review

2. Team Members and Roles Devon Monaco (ME) Emily Roberts-Sovie (IE)
Project Manager
Emily Roberts-Sovie (IE)
Safety, Statistics, and Documentation Manager
Joseph Lee (ME)
Lead Mechanical Engineer, Facilitator
Thomas Bizon (EE)
Lead Electrical Engineer
Nathan Faulknor (EE)
Systems Integration
Yevgeniy Parfilko (ME)
ME Interface Engineer
Kenny Ung (EE)
Electrical Design Engineer

3. Agenda MSD I Project Background
Review problem statement and deliverables
Review stakeholders and use scenarios
Updated List of Needs and Engineering Requirements
Additional Benchmarking
Functional Decomposition
Concept Development
Morphological Chart
Pugh Analysis
System Level Proposal
Feasibility Analysis
Potential Test Plan
Refined Risk Analysis Chart
Up to Date Project Schedule
Time for Questions

4. Inherited State of Router, P14311 (Rev1)
Trial Mach3 software for converting Eagle PCB layouts to milling tool path with router
Vacuum table clamp and vacuum/brush debris collection as single subsystem
Manual homing and datum zeroing with computer jog keys
7”x7” max board size
PC, vacuum, and Bosch router enclosed in single roller unit
Monitor and keyboard on separate table

5. Problem Statement
Printed Circuit Boards (PCBs) are expensive to produce.
MSD team P14311 developed a PCB Isolation Router that functioned but needed performance improvements.
Several features are needed for open use to students:
Automated tool setup and homing
Safe debris collection system
User-friendly controls and operating procedures
Low noise level during operation
Refined router must operate predictably and precisely for corporate clients.

6. Project Deliverables
Analyze the design of the current router and identify all improvement areas.
Modify the design to improve operator controls, setup automation, debris and noise management.
Define and document clear procedures from use scenarios and personal experience.
Compile a quick start guide, user manual, troubleshooting guide, maintenance schedule and replacement parts list.

7. Stakeholders Primary Secondary RIT Students Inventors/tinkerers
Jeff Lonneville
CAST Electronics Lab
Secondary
Investors
MSD Team
RIT

8. Use Scenarios
Novice User
Outside Company
Experienced User

9. Use Scenarios Flow Chart

10. Prioritized List of Needs (1-3-9)
Customer Rqmt. #
Importance
Description
Comments/Status
CR1 3
Capable of routing traces for finer pitched SMD's
Tolerances currently too large
CR2 9
Safe and easy to operate by minimally trained (<0.5 hour) user
Took several days to get machine operating
CR3
Have quick start, service, and detailed troubleshooting/operation manuals
Improvements needed to documentation
CR4
Cost less than commercial systems on the market
Factor in lead time and process costs
CR5
Require minimal maintenance and part replacement
Frequent drill bit breakage
CR6
No mechanical, electrical, environmental, or health related hazards to operators of those in the general lab area
Concerns with noise level and particulate matter
CR7
Alignment system capable of auto homing
Need for more precision and repeatability
CR8 1
Automatic tool change and recognition
Convenience feature
CR9
Visual feedback system for error detection
Difficult to see traces through glass
CR10
Improve debris removal system
Messy and dangerous for operation
CR11
Contain all components of system in one unit
Detached monitor and keyboard
CR12
Rout PCB rapidly
Long setup time
CR13
Ability to flip and zero reverse side of board accurately
No flipping method or ability to re-zero flipped board

11. Engineering Requirements
Importance
Source
Engr. Requirement (metric)
Unit of Measure
Marginal Value
Ideal Value
P14311 1 9
CR6
Noise Generation
dBA
<100
<65
Marginal pass 2
CR1
Minimum Width Between Traces Supported
inches
0.020
0.016
marginal pass 3
CR4
Manufacturing Cost $
2800
2000
Fail 4
CR5
Unit Reliability (mean time between failures)
TBD 5
Mean to time between maintenance
hours 50
100 6
CR3, 7
Minimum Tolerance to locating positions on board
0.005
0.001 7
CR5, 8
Bit Replacement Time
minutes
<1 8
Feed Rate
in/minute 10 20
CR2, 3
Time for initial machine set-up
Maximum Compatible Board Size
inch x inch
5 x 5
8 x 8 11
Minimum Compatible Board Size
2 x 2
1 x 1 12
CR2, 11
Up to date PC & software for system control
Binary No
Yes
Pass  13
CR2, 3, 5
Minimize Operator Training
1.5
.5 hours 14
Router Speed
rpm
15000
30000 15
C10
Debris Removal (Copper and Substrate)
mg ratio
0.90
0.99 16
Total Indicated Runout
<.0006
<0.0004 17
CR7, 10
Vacuum Table Force
lbs force 30 40 18
Max Power Consumption for entire system
watts
1920
1800 19
Aesthetic wiring and schematics
Engineering Requirements

12. Current Methods of PCB Routing
Criteria
Chemical Etching
Commercial
MITS Auto Lab
LaserJet PCB Printing
P14311 PCB Router
Max. Workable Area (in)
Most Sizes
9 x 11.8
8 x 10
7 x 7
Minimum Trace Spacing (mm)
x ≥ 0.1
x ≥ 0.17
0.51 < x < 0.41
Material Depth Removal (precision)
Varies on process
0.2 mm; 1.18” maximum thickness of board
3.175 mm
Cycle time/Feed Rate
Weeks
55 Drill Cycles/min
25 to 60 min (total)
10 in/min
Space Requirements
Room-size
46.7 ft3
32 ft3
40 ft3
Maximum Noise Output (dB)
minimal
low
100 < x < 75
Cost
Varied
$15,200
~$500
$4000

13. Additional Benchmarking- RIT’s ME Lab PCB Router
T-Tech PCB router system- limited specs on site
Mobile X-Y axis bed
Z axis solenoid control with hard stop pad
Separate vacuum unit with individual debris vacuum and vacuum table pump
EXPENSIVE
For all of the features we wish to have on our router, this unit costs upwards of $20,000

14. Functional Decomposition

15. Morphological Chart for Concept Development

16. Pugh Analysis for Concept Selection: Securing Board

17. Pugh Analysis for Concept Selection: Auto Homing

18. Pugh Analysis for Concept Selection: Debris Collection

19. System Level Proposal New vacuum debris collection system
Redesign vacuum inlet assembly
Include improved vacuum with more powerful motor and higher flow rate
Separate vacuum table and debris collection unit
Redesign vacuum table assembly
Include vacuum pump with high sealing pressure
Separate vacuum table and debris collection to eliminate interface losses
Make single standard size vacuum table top
Implement automatic homing
Eliminate need for user jogging to home position
Set permanent global zero in mach3 code
Include proximity sensors for home location verification
Improve limit switches for hard stop backup

20. System Level Proposal Maximize tool life and trace width capabilities
Provide predetermined ideal drill bits and sizes
Enable spindle speed and feed rate selection for tool optimization
Improved user experience
Quick start guides
Troubleshooting documentation
Visual feedback
Intuitive user interface
System contained in single unit
Dampen noise generated by system

21. System Architecture (Block Diagram)
Revised from P14311 documentation

22. Board Architecture (Block Diagram)
Revised from P14311 documentation

23. Power Distribution
Revised from P14311 documentation

24. Feasibility Analysis Test Observe Analyze Demonstrate
Current Working Router

25. Completed Work, Tests, and Updates
Locker inventory
Running old PC and software
Purchasing full software license and installing
Updating to new PC
Including 2nd monitor and allowing for video feed
Investigating drill bits and deciding on best styles for purchasing and testing
Sourcing and purchasing PCB material
Sourcing and purchasing monitor brackets
Hands on time with machine running test profiles and routing boards
Investigating background code in mach3 and implementing custom macros
Performing and compiling student interviews for refined requirements

26. Vacuum Table Calculations
When analyzing the ShopVac system calculations from the last group:
The team failed to account for the maximum holding pressure of ShopVac
The team incorrectly assumed that there would be ~1CFM of flow
ShopVac Specs Vacuum Pump Specs

28. Vacuum Debris Collection Calculations
Reasons For Loss
Support structures left in 3D printed parts
3D printed joints do not create a good seal
Air is leaking out of the sides of the vacuum table

29. Drill Bit Tool Life Calculations
10,000 linear inches of cut expected at 20 in/min feed rate
Roughly 100 boards per tool life
Breakage caused by high feed rate + deep plunge
Four tools needed to cut board:
1: Drill for through-holes
2: Fine-tip trace isolation tool
3: Wide-tip rubout tool
4: Deep-plunge cutout tool 1 2 3 4

30. Proposed Purchases/Budget Actual (Team Spending)
Budget Estimate
Proposed Purchases/Budget
Item
Use/Description
Supplier
Worst Case
Most Likely Case
Actual (Team Spending)
Alignment System
Auto Homing with Precision
Unknown
$500.00
$200.00
TBD
Wire
Rewire to color code, and design for service
$300.00
$250.00
Mach 3 License
Improve bugs with program, z-axis precision
ArtSoft
$175.00
Drill Bits
For testing, bit analysis, and selection
Think & Tinker
$101.06
Misc Parts, Hardware, 3D Printing, Etc.
Unnaccounted for extra expenses, sacrificial material, etc. (to date)
$0.00
New Vacuum
More powerful to improve debris removal, quiet
ShopVac
$150.00
Replacement Router
Bausch router has been discontinued
$100.00
PCB Boards
For testing and machine familiarity
DigiKey/Mouser
Misc Labor
Machining, etc.
RIT/Other
$50.00
Computer Monitor Dual Mount
Make the machine one unit
TaoTronics
$55.00
Wire Duct, Heat Shrink, Etc.
Wire management, improve reliability
$35.00
Vacuum Pump
Hold PCB board onto table
unknown
$75.00
$40.00
Sound Absorbing Material
Reduce noise and impove working environment
New Computer/Monitor
Upgrade computer and provide for camera view
RIT
Total:
$2,250.00
$1,610.00
$331.06

31. Budget Estimate

32. Refined Risks AssessmentID
Risk Item
Effect
Cause
Likelihood
Severity
Importance
Action to Minimize Risk
Owner 1
Breaking Bits
Circuit board ruined, extra costs, time spent on maintenance
Improper feed rate, uneven surface, wrong material 9 3 27
Documentation of bit use, statistical study, (bit selection option?)
Team 2
Dusting Issues
Respiratory issues, OSHA compliance issues, can get into small parts and cause mechanical failure
Vacuum not powerful enough or close enough to routing, user not using PPE if needed 6 36
Get a stronger vacuum, find a way to get the vacuum as close to the dust as possible, find the particle size of the dust, do not have the operator clean it off by hand
Mechanical Team/Safety
Controls Failure
Circuit ruined, extra time
Unable to control z axis, programming issues 54
Update Mach 3, investigate z-axis motor, analyze drill bit fit and slip
Electrical Team 4
Operator Error
Injury, machine breakage, RIT shuts machine down, circuit board ruined
Improper training, unclear instructions, unlabeled parts, poor user interface
Standard Work, Instructions posted on machine, training before use, poka-yokes, improve user interface
Safety 5
Electrical Failure
Shortage, loss of power, blow fuse, cannot use machine, broken wall plug
Movements, overheating, improper wiring
Standard Inspection/Replacement of wires, reorganize wires, rewire any improperly done wires
Computer/Software Failure
Cannot use machine
Older hardware, outdated software 18
Inspections of hardware, regular software updates 7
Router Failure
Ruins board, cannot use machine
Over use, overheating
Buy extra router
Mechanical Team

33. Potential Test Plans
Produce machine troubleshooting/errors data sheet and analyze
Determine machine reliability
Compile troubleshooting requirements
Produce drill bit data sheet and analyze tool life, tool wear, breakage
Optimize tools and maintenance requirements
Use load cell to confirm breaking force of vacuum table hold in x,y,z
Ensure board security and trace spacing
Use flow meter to analyze vacuum debris inlet flow rate
With and without HEPA filter
Experiment with mach3 customized macros
Improved functions
Extended tool life
Measure change in board weight vs debris collected by vacuum
Minimize interference of debris with routing
Mitigate airborne particulates
Measure sound produced with decibel meter

34. Updated Project Schedule

35. Upcoming Project Schedule

36. WBS Inspired Weekly Tasks

37. Questions?