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System Level Design Review

Reciprocating Friction TesterTuesday, September 30th, 2014

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P15660: Armature SubsystemEric Kutil (ME): Project Manager

Specialty: Solid Modeling and Machining

Chris Karamanos (IE): Data ManagerSpecialty: Process Improvement

Reba Conway (ME): Note TakerSpecialty: Solid Modeling and GD&T

Kolby Irving (EE): GatekeeperSpecialty: Lab-View Software

Emeka Okoye (EE): Supply ManagerSpecialty: Electronic Hardware

Gary Werth: Project Guide

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Agenda● Review

o Project Backgroundo Stakeholderso Problem Statement & Project

Deliverableso Customer Needso Engineering Requirementso House of Qualityo Risk Assessment

● Action Items and Interviewso Research Student Interviewo Welling Interviewo Interface with base team

● System Designo Analysis - Functional

Decomposition

● Concept & Architecture Developmento Benchmarking of all functionso Morph Charts of Options 1-5o Pugh Charto Engineering Analysiso Proposed Designo Secondary Design

● Test Plan● Project Plan

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Review

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Project Background

● Tests the wear and friction of materials● Design a reciprocating sliding contact friction test rig

o Ball-on-plate

FRICTION TESTER PROJECT

TWO TEAM COLLABORATIVE

BUILD

Group A Armature

SubsystemP15660

Group B Reciprocation

SubsystemP15661

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Stakeholders

Dr. Iglesias Victoria● Primary stakeholder, sponsor and customer

Other important stakeholders● Friction tester reciprocating team (P15661)!

o Communication between teams is key for success

● Research students using Dr. Iglesias’s Labo Will be operating the friction testers as well

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Problem Statement & Project Deliverables Current State:● The reciprocating friction testers are too expensive, or not the current

testing application

Desired State:● Fully functional reciprocating friction tester by the end of MSDII!

Project Goals:● Design and build an armature which will be attached to the reciprocating

base made by P15561 team

Constraints:● The armature must provide constant & accurate vertical Normal Force

o Weight of armature can’t affect normal force● Single point contact force variable from 0N to 20N● All data obtained must be stored and displayed● Budget of $1500, $2500 shared between both teams

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Customer Needs & Requirements

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Engineering Requirements

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Hou

se o

f Qua

lity

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Risk Assessment

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Completed Action Items and Important Interviews

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Action Items and Open Items from Last Review

● Met with Research Student to discuss operation and ease of use

● Scheduled a meeting with Prof. Wellin to discuss LabView options

● Discussed system interaction with Reciprocating Team (P15661)

Defined interface on baseConfirmed Responsibility of Functions and Designing

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Research Student InterviewMet with the current research student in the lab to discuss ease of use and operation of the current rotating friction tester. Below is what we learned from the interview:

Discussed likes about armature● Armature motion

o Rotate about baseo X translation for easy adjustabilityo Pin holder (set screws), quick and easy

Possible design concerns● Using weights with open slots

o Could slide off due to vibration● Motor capabilities

o Not powerful enough to quickly accelerateImprovements● LABView interface

o Difficult to use, clumsy

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John Wellin InterviewHad an interview with Professor Wellin and Dr. Iglesias to discuss LABView and other electrical components of the friction tester. Some key learnings:

Computer Hardware and Software● A single LABView interface can feasibly control both the rotating disk and

reciprocating friction test stations, however not simultaneously

Sensors to measure Friction Force● Strain gauges aren’t ideal

o Budget, need signal conditioner and DAQ hardware to convert signal to force

o Accuracyo Needs to be installed in perfect orientation, very difficult

● Mr. Wellen recommended different sensorso Torque cello Load cell

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Interface with Reciprocating TeamDiscussed and finalized interface between teams and who is responsible for certain functions.

Mounting Interface Constraints ● Reciprocating base team will mount and fix their subsystem to the

foundation base plate in a predefined location. o Min/max height from top of specimen to foundation plate provided by

base teamo Based on final design, distance from center of bolt hole pattern to

location of the ball holder will be provided to base team

Design Responsibility● Armature team will be designing friction tester safety cover● Base team is in charge of LABView programming and software

o Will provide and send voltage output signal that represents friction force to base team

● Creo software will be used by both teams

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System Design

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Analysis: Functional Decomposition

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Armature Functions

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Concept Development

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Benchmarking: Mounting Armature to Base Plate

Feasible designs● Screws● Bolts

Not Feasible Designs● Welding● Rivets

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Benchmarking: Load Application

Feasible designs● Test stand● Stackable weights, option B and C

Not feasible designs● Threaded screw tensile test system● Stackable weights, Option A

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Benchmarking:Counterbalance

Feasible designs● Weight on fine threaded rod● Triple Beam Balance

Not Feasible Designs● Stackable Weights

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Benchmarking:Pin Holder

Feasible designs● Set Screw● Drill Chuck● Collet● Clamps

Not feasible designs● Magnets

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Benchmarking:Recording Friction Force

Load Cell is best for our setup

Load CellData

LoggerPC

(LABView)

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Benchmarking: Safety Cover

Pin Style

Style 1

Style 7

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Morph Chart Based off Benchmarking

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Morph Chart: Option 1 (Datum)

Option 1 which is the datum, is identical to the rotating friction tester located in the lab.

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Option 1 (Datum) Design

Stackable Weights to Apply

Normal Force

Weight on fine Threaded Screw to

Counterbalance

Set Screw to Secure

Holder

Bolts to secure Armature to Foundation Crank

Wheel to Adjust in X

Free Standing

Cover

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Morph Chart: Option 2Key Differences to Datum:● Safety cover with hinges and

magnets● Drill chuck to secure specimen● Y axis Adjustment

Pros1. Cover is easier to use and safer2. Adjustable in Y axis3. Quick way to secure holder

Cons4. Slightly more expensive due to

drill chuck 5. Slightly more complex design

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Morph Chart: Option 3Key Differences to Datum:● Safety cover with access door● Drill chuck to secure specimen● Triple-beam counterbalance● Y axis Adjustment

Pros1. Cover is easier to use and safer2. Adjustable in Y axis3. Quick way to secure holder4. More accurate counterbalance

Cons5. More expensive due to key

differences6. More complex design7. Larger armature size due to triple-

beam counterbalance

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Morph Chart: Option 4Key Differences to Datum (Almost Identical):● Safety cover with hinges and

magnets● Y axis Adjustment

Pros1. Cover is easier to use and safer2. Adjustable in the Y axis3. Cheapest option besides Datum4. Lowest risk

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Morph Chart: Option 5Key Differences to Datum :● Safety cover with access door● Y axis Adjustment● Completely different normal force

application design

Pros1. Cover is easier to use and safer2. Adjustable in the Y axis3. Very easy way to apply load4. Wide range of loads5. No counterbalance necessary6. Simple and smaller design

Cons7. More expensive due to extra force

gauge and test stand8. May be difficult to incorporate

strain gauge, moderate risk

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Pugh ChartBased off our Pugh chart, the winner with our chosen criteria is option 5. This option may have many positives but also has a moderate risk and high cost.

Option 4 is the runner up due to its similarity to the rotating friction tester, low risk.

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Proposed Design

Reciprocating base

Loud/Torque Cell

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System Architecture

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Engineering Analysis

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Min/Max Friction Force

Coefficient of FrictionLubricated Test (Min) = 0.01 uDry Test (Max) = 0.8 u

Testing load rangesMinimum Force = 0.5 NMaximum Force = 20 N

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Test Plan OutlineTest Load Cell● Verify that cell can measure friction within percent error desired● Make sure that cell can measure min and max friction force● Test vibration is system so that it does not affect friction force

Test User interface● Verify ease of use● Make sure data on LABView is correct and accurate

Test counter balance methods● Verify counterbalance accuracy● Verify the amount of normal force load is correct and accurate

Detection Systems Test

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Project Plan

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Problems Encountered

● Defining gauge type o Strain gauge to load cell

● Determining weights for normal force

● Set screws vs. Drill chucks

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Action Items

Continue researching and selecting sensors for recording friction force● Also determine sensor integration

Interview with Iglesias to determine which design and aspects she prefers

Email Test Stand Load Applicator manufacturer for minimum and maximum loads.● Needs to exert accurate normal force from 0.5N to 20N

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Questions?

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Extraneous Information

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Feasibility Questions to Answer 1. Can the system counterbalance the armature with a Normal Force from 0-

20 N? (Analysis/Prototyping)

2. Will the pin holder supply enough force to allow for approximately zero motion in the pin? (Analysis)

3. Will the armature be able to accurately measure friction within a certain percent error using the gauges and sensors previously discussed? (Benchmarking)

4. Which guard is the easiest for the user to use? (Benchmarking/Prototyping)

5. How fast of a moving speed can our sensor accurately measure? (Benchmarking/Analysis)