Design and Characterization of Diamond-Like Carbon Coated
Kinematic Contacts for Improved Coupling Precision and Wear Resistance
by
3ACHUSETTS MM7fUTE
OF TECHNOLOGY
Tian Yi Wang
Sc.B. Mechanical Engineering
Massachusetts Institute of Technology, 2014
JUL 3 2014
LIBRARIES
Submitted to the Department of Mechanical Engineering
in Partial Fulfillment of the Requirements for the Degree of
Bachelor of Science in Mechanical Engineering
at the
Massachusetts Institute of Technology
June 2014
2014 Massachusetts Institute of Technology
All rights reserved.
.Signature redacted
Signature of Author. ..
_
Oe
.....................................................
Department of Mechanical Engineering
May 21, 2014
Certified by........
beL7
.-
-
Signature redacted
Signature redacted
Accepted by...............
........................................
Martin L. Culpepper
Professor of Mechanical Engineering
Thesis Supervisor
............................................
Anette Hosoi
Professor of Mechanical Engineering
Chairman, Undergraduate Thesis Committee
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2
Design and Characterization of Diamond-Like Carbon Coated
Kinematic Contacts for Improved Coupling Precision and Wear Resistance
by
Tian Yi Wang
Submitted to the Department of Mechanical Engineering
on May 21, 2014 in Partial Fulfillment of the
Requirements for the Degree of Bachelor of Science in
Mechanical Engineering
ABSTRACT
Kinematic couplings are used to precisely locate components by constraining all 6 degrees of
freedom. The repeatability of kinematic couplings range from hundreds-of-microns down to
tens-of-nanometers. This paper introduces diamond-like carbon (DLC) coatings as a means to
improve the repeatability of kinematic couplings. Coatings with the help of lubricants have been
used in the past to improve the repeatability of kinematic couplings, but DLC coatings offer the
opportunity to improve repeatability without the use of lubricants. This will allow for use of
kinematic couplings in tools and instrumentation such as scanning electron microscopes (SEMs)
where lubricants cannot be used. The experimental results from this experimental setup
concluded that kinematic couplings coated with DLC contacts have a repeatability on the order
of microns compared to steel contact which have a repeatability on the order of tens-of-microns.
The DLC contacts have a repeatability at least loX better than that of the steel contacts.
Thesis Supervisor:
Title:
Martin L. Culpepper
Professor of Mechanical Engineering
3
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4
ACKNOWLEDGEMENTS
First and foremost I would like to thank Professor Culpepper for his guidance and
support. Without him, this thesis would not have been possible. He challenged me to think more
like an engineer and make my castles in the air become a reality. I have learned so much from
him during my time as an undergraduate student. Not only was he a supportive advisor in my
academic endeavors, but also someone I turned to for advice.
I am grateful to Aaron Ramirez for his guidance and support, for those endless hours he
spent reviewing my designs and teaching me everything I should have learned but did not and
was patient and understanding while doing it.
This thesis would not have been possible without the help of Gerry Wentworth and Bill
Buckley in the Laboratory for Manufacturing and Productivity (LMP) machine shop. I would
like to thank Gerry and Bill, without them I would not have an experimental setup.
Working in the Precision Compliant Systems Laboratory (PCSL) I have come to know
many individuals who have graciously offered their help, support, and advice.
I would
especially like to thank Marcel Thomas for spending endless hours helping me and making sure
that I finished everything I needed to move forward. He always had a knack for showing up at
the times I needed help the most, usually the wee hours of the morning. I am grateful for his
advice and patience. I would like to thank Brandon Evans for helping me with my experimental
setup and analysis of my data. I would also like to thank Lucy Du. No one understood what I
was going through more than her. I am grateful for her spending endless hours in lab with me,
helping me, supporting me, and rooting for me.
I am thankful to Saana McDaniel for making sure that I had everything I needed for my
thesis. From scheduling meetings to ordering parts, it would not have been possible without her
help.
I am grateful to Professor Reis for being my academic advisor and guiding me during my
time at MIT. He always made sure I had all my ducks in a row and was ready to take on new
challenges.
Starting my sophomore year I had the pleasure of working for Maria Telleria and Ahmed
Helal. I am thankful to her for her guidance and support. She was the first person I worked for
5
as an undergraduate researcher and I learned more than I ever could have imagined during our
two years together. She encouraged me to express my creative and unrealistic ideas and taught
me how to make them into reality. Even after she graduated, she was still available to offer her
guidance.
Additionally, I would like to thank Ahmed Helal for his support during my
undergraduate years. He always offered a helping hand whenever I needed it and made my time
at MIT more enjoyable. I am grateful for his encouragement in everything I pursued and his
willingness to help me whenever he could.
I would also like to thank Sorin Marcovici for being my mentor. He was always so
understanding and knew exactly what I was going through. His advice has helped me develop as
an engineer, young professional, and a more patient and understanding person.
Additionally I would like to thank Troy Hoffa for his love, support, patience and help
especially in the times I needed it the most. Words cannot express my gratitude for having him
in my life.
Last but certainly not least I would like to thank my family and friends. To my mom,
dad, and sister who have always believed in me, challenged me to be the best that I could be, and
for their understanding. I would not be where I am today without their love and support. To my
friends who put up with my endless hours spent working and try to work with my schedule, who
understand what I am going through and always support me, thank you, I could not have done it
without you all.
6
CONTENTS
Abstract................
3
~
Acknowledgements
5
Contents
7
00-0,00"11
Ti ibles
wo
1..
13
1.1
Purpose, Importance, Impact ....................................................................................
13
1.2
Current Kinematic Couplings....................................................................................
14
1.3
Applications of Kinematic Couplings.........................................................................
14
1.4
Repeatability .................................................................................................................
15
1.5
Diamond-Like Carbon Coatings...............................................................................
15
1.6
Thesis Overview .......................................................................................................
16
17
2..
2.1
Repeatability model..............................................
17
2.2
Minimizing Friction............................................
17
2.3
Wear Factor.......................................................................................................
18
2.4
Expected Performance ...........................................................................................
18
3.1
Theory of Design of Kinematic Coupling .................................................................
21
3.2
Kinem atic Coupling Design.......................................................................................
25
3.3
Diamond-Like Carbon Coatings ...............................................................................
26
3.
3.3.1
Comparison of DLC Coatings................................................................................
3.3.2 DLC Coating Selection .........................................................................................
27
28
4.,
4.1
Fabrication of Kinematic Coupling ..........................................................................
7
29
4.2
Assem bly ....................................................................................................................... 31
5. .. ..
.......................
5.1
5.2
33
Instrum entation and Setup ............................................................................................ 33
Experim ents .................................................................................................................. 35
37
6.1
6.2
Steel-Steel Results ........................................................................................................ 38
DLC-DLjC Results ........................................................................................................ 42
. .... 0 .....
.........
47
48
49
A .1
B
Ao2
CAD of Kinem atic Coupling ........................................................................................ 49
Drawings ..................................................................... o................................................. 50
A -3
Process Plans ................................................................................................................. 51
........
53
......
57
61
.......0 .....o..oo...,.oo..o..ooo ......
8
......
......63
FIGURES
Figure 1.1: Kinematic coupling [1...............................................................................................
13
Figure 2.1: This is a plot of the expected performance of DLC-DLC contacts and steel-steel
contacts. ........................................................................................................................................
19
Figure 3.1: Kinematic coupling with 3 grooves [6]...................................................................
21
Figure 3.2: Parameters for optimizing the design of 3 groove kinematic couplings [6]. ......... 22
Figure 3.3: Assembled view of the CAD of the kinematic coupling.........................................
25
Figure 3.4: Groove side of the kinematic coupling...................................................................
26
Figure 3.5: Ball side of the kinematic coupling........................................................................
26
Figure 3.6: Ternary phase diagram for DLC coatings compared to graphite and diamond. This
shows the sp 3 to sp 2 ratio as well as the hydrogen content of the coating [4]. ........................ 28
Figure 4.1: Tool path generated in HSM Works compared to the SolidWorks CAD of the veegrooves..........................................................................................................................................
29
Figure 4.2: Fabricated vee-groove side of the kinematic coupling...........................................
30
Figure 4.3: Tool path generated in HSM Works compared to the SolidWorks CAD of the ball
side................................................................................................................................................
30
Figure 4.4: Fabricated ball side of the kinematic coupling.......................................................
31
Figure 4.5: Ball side of the kinematic coupling. The bottom two balls are glued on with epoxy.
The top pocket does not have a ball in it. .................................................................................
31
Figure 4.6: Vee-groove side of the kinematic coupling was fly cut before the steel gauge blocks
coated with DLC were glued onto the vee-grooves with epoxy................................................
32
Figure 5.1: (a) Vee-groove side of kinematic coupling with DLC coated gauge blocks glued on
with epoxy to the machined vee-grooves. (b) Ball side of kinematic coupling with DLC coating
stainless steel balls glued on with epoxy. ................................................................................
33
Figure 5.2: Experimental setup..................................................................................................
34
Figure 5.3: The aluminum block with steel blocks glued on either sides is mounted to the top of
the kinematic coupling, the side with the balls, to load the kinematic coupling. .....................
35
Figure 6.1: Capacitance probe arrangement on experimental set up........................................
38
9
Figure 6.2: Summary of results for steel to steel contacts............................................................
41
Figure 6.3: Translational repeatability of kinematic coupling with steel to steel contacts..... 42
Figure 6.4: Summary of results for DLC to DLC contacts.......................................................
45
Figure 6.5: Repeatability of kinematic coupling with DLC to DLC contacts..........................
10
46
TABLES
Table 1.1: Comparison of coupling mechanisms [2]................................................................
14
Table 1.2 Repeatability comparison for different coupling mechanisms [1]............................
14
Table 1.3: Comparison of coefficient of friction for different types of commonly used coatings.
The performance gain was calculated by dividing the lowest coefficient of friction of DLC (0.05)
16
by the coefficient of friction of the respective coating [5].......................................................
Table 3.1: Summary of the main categories of DLC coatings and their properties................. 27
42
Table 6.1: lo and 3o for the repeatability measurements for steel-steel.................................
Table 6.2: l and 3a for the repeatability measurements for DLC-DLC.................................
11
46
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12
CHAPTER
1
INTRODUCTION
1.1 Purpose, Importance, Impact
The purpose of this research was to understand the effect of diamond-like carbon (DLC)
coatings on the repeatability of kinematic couplings. Different coatings have been utilized in the
past to decrease the coefficient of friction in kinematic couplings, but DLC coatings have not
been explored. This research encompassed modeling the repeatability of kinematic couplings
utilizing DLC coating and the fabrication of kinematic couplings with balls and vee-grooves
coated with DLC. This coating has the potential to increase the repeatability of kinematic
couplings to the tens-of-nanometers at a low-cost and without the use of lubricants. Increasing
the repeatability to the tens-of-nanometers will allow for better alignment and positioning in
tools and instrumentation such as scanning electron microscopes (SEMs) where lubricants
cannot be used. This improvement will allow researchers to remove samples from SEMs and
place them back in the machine without needing to locate the sample again. The impact of this
research has the potential to improve diagnostic rate, quality, and cost. This thesis focuses on
optimizing kinematic couplings shown in Figure 1.1 to increase repeatability.
From
experimentation, the performance of the kinematic coupling with DLC coating was 10X better
than the repeatability of the kinematic coupling without the coating.
Figure 1.1: Kinematic coupling [1].
13
1.2 Current Kinematic Couplings
Kinematic couplings are useful for precisely locating components and achieve this
function by deterministically constraining six degrees of freedom. Depending on requirements
of the constraint, different couplings can be utilized. The following constraints are summarized
in the Table 1.1: basic pin join, elastic averaging, planar kinematic, quasi-kinematic, and
kinematic. These couplings are compared in terms of contact type, repeatability, stiffness/load
capacity, and industrially ideal [2]. Table 1.1 compares the range of repeatability of coupling
mechanisms. Not only do kinematic couplings have the widest range of repeatability, but also
achieve the highest repeatability.
Table 1.1: Comparison of coupling mechanisms [2].
Coupftg Type
Conftd-tType
RpeIIIIb~ht
Basic Pin Joint
Surface
Poor (~5pum)
High
Fair
Elastic Averagg
Surface
Fair (-1pm)
High
Good
Plaar Kinematic
Mixed
Good
High
Good
Line
Good (-0.5pm)
Medium to High
Good
Point
Excellent (-O.O1m)
Varies (Usually Low)
Poor
Quasi-K
Kinematic
S-10
ama/d Caft
Ihus~tri
im[a
Table 1.2 Repeatability comparison for different coupling mechanisms [1].
0.01 Mmu
1.0 am
Pinned Joints
I1
Elastic Averaging
Quasi-Kinematic Couplings
Kinematic Couplings
1.3 Applications of Kinematic Couplings
The applications of kinematic couplings range from fiber optics to automotive parts to large
array telescopes. With such a wide variety of applications, many challenges are faced when
designing kinematic couplings. Each system size and required precision brings about new design
challenges [2].
14
1.4 Repeatability
The ability to increase repeatability to tens-of-nanometers will allow meso-scale systems or
even larger systems to attain the level of repeatability needed. Four criteria were developed to
optimize kinematic couplings: 1) Maxwell's criterion, 2) maximizing the modal frequency, 3)
minimizing frictional nonrepeatability, and 4) maximizing the limiting coefficient of friction [31.
The last two criteria suggest that friction is a determining factor in the repeatability of kinematic
couplings. Optimizing friction will therefore result in greater repeatability.
1.5 Diamond-Like Carbon Coatings
DLC coatings have properties that can increase repeatability of kinematic couplings.
Within the last 30 years, research on DLC coatings has increased due to technology
advancements and commercial interests in the properties of DLC coatings. These coatings have
unique material properties: high mechanical strength, high hardness, chemical inertness,
excellent thermal conductivity, extremely low thermal expansion, low friction, and good wear
resistance. In regards to kinematic couplings, low friction, high hardness, and wear resistance
makes DLC an ideal coating to use to optimize the performance of kinematic couplings [4].
Coatings have been utilized in the past to optimize the performance of kinematic
couplings. Table 1.3 on the following page consists of commonly used coatings compared to
DLC coating. The performance gain is calculated by dividing the lowest coefficient of friction
of DLC, 0.05, by the coefficient of friction of the respective coating, TiN, TiCN, TiAIN, CrN,
and ZrN. The performance gain of DLC coating is at least four times that of the next comparable
coating.
15
Table 1.3: Comparison of coefficient of friction for different types of commonly used coatings.
The
performance gain was calculated by dividing the lowest coefficient of friction of DLC (0.05) by the
coefficient
of friction of the respective coating [5].
DLC
0.05-0.1
2500-3300
0.5-1
TiN
0.5
2200
0.1
TiCN
0.4
2800
0.125
TiAIN
0.6
3500
0.08
CrN
0.5
2200
0.1
ZrN
0.5
3300
0.1
Steel-steel
0.5-0.8
Varies
0.06-0.1
1.6 Thesis Overview
The first step is to understand how repeatability is characterized by modeling. Chapter 2
utilizes the model developed by Hale to justify reducing friction to optimize the repeatability of
kinematic couplings.
Chapter 3 focuses on the theory of design utilizing Johnson's contact
mechanics as well as the design of the kinematic coupling utilizing Slocum's design principles
for three groove kinematic couplings. Following the design is a comparison of the different
types of DLC coatings and the justification for choosing one particular DLC coating instead of
other coatings.
Chapter 4 consists of fabrication and assembly of the kinematic coupling.
Chapter 5 describes the experimental setup and the experiments conducted. Chapter 6 consists
of the results from experimentation. Lastly, Chapter 7 concludes the thesis and summarizes the
work.
16
CHAPTER
2
MODEL
2.1 Repeatability model
Utilizing
Maxwell's criterion,
developed
Hale
a model
to predict
frictional
nonrepeatability. The nonrepeatability, p, is a function of friction, p, the radius of the ball, R, the
applied load, P, and the elastic modulus of the materials in the coupling, E. Equation 2.1, below,
shows that the relationship between friction and nonrepeatability is linear.
1
((3
Z
2
Equation 2.1
3
Hale developed an additional nonrepeatability equation specifically for symmetric threevee coupling. This model assumes that the nonrepeatability at the center will be horizontal, thus
resulting in nonrepeatability as a function of friction, p, the external load applied, P, stiffness, k,
and the angle of the vee-grooves, a. The resulting model, Equation 2.2 below, also shows that
the relationship between friction and nonrepeatability is linear [3].
P
18ksin2 acosa
(2V3
+ cosa + sin2a)
Equation 2.2
2.2 Minimizing Friction
Hale identified four criteria to optimize kinematic couplings: 1) Maxwell's criterion, 2)
maximizing the modal frequency, 3) minimizing frictional nonrepeatability, and 4) maximizing
the limiting coefficient of friction [3]. The last two criteria indicate that friction is a determining
17
factor in the repeatability of kinematic couplings therefore optimizing friction will result in
greater repeatability.
The models developed by Hale show that nonrepeatability has a linear
relationship with friction, thus if friction increases, nonrepeatability also increases.
As mentioned previously, coatings have been utilized to optimize the repeatability of
kinematic couplings.
Table 1.3 summarizes commonly used coatings to reduce friction
compared to steel-steel interfaces as well as DLC-DLC interfaces.
Utilizing coatings can
decrease friction by an order of magnitude thus decreasing nonrepeatability by an order of
magnitude.
Most coatings in Table 1.3 have a coefficient of friction between 0.4 and 0.6.
Compared to the steel-steel coefficient of friction of 0.5 - 0.8, utilizing a coating would result in
a maximum of 2X gain. DLC coatings have a coefficient of friction ranging from 0.05 - 0.1,
which could result in a 16X gain.
2.3 Wear Factor
Wear factor is a measure of a material's resistance to wear as a function of volume of
material lost, force, velocity at the contact location, and time. The wear factor of steel is 1 x
103- 1 X 10-2
M3Tewa
Nm . The
ato fDCi 1
wear factor of DLC is
-
5 X 10-17 M3
Nm .
Although repeatability is
not a function of the wear factor, the performance of the kinematic coupling does change over
time as material is removed from the contact regions through coupling and decoupling. DLC has
a smaller wear factor by 14 to 15 orders of magnitude, thus the volume of material that is
removed per Newton-meter is at least 14 magnitudes less in DLC contacts compared to steel
contacts.
2.4 Expected Performance
Utilizing Hale's model for a symmetric three-vee coupling, Equation 2.2, the expected
performance for steel-steel contacts and for DLC-DLC contacts was modeled. This calculation
uses the range 0.5 - 0.8 as the coefficient of friction for steel and 0.05-1 as the coefficient of
friction for DLC. The load applied, P, is 27 N and the angle of the vee-grooves, a, is 45'. The
performance of DLC-DLC contacts are approximately 5X to 15X the repeatability of steel-steel
contacts. The results are plotted in Figure 2.1.
18
Repeatability
500
Steel
o0
400-
Q
cU
300-
-
200
DLC
100
00
EJ
0.1
67.35 nm, p=0.1
33.7 nm, p=0.0 5
0.2
0.3
Steel
DIC
0.4
0.5
0.6
0.7
0.8
coefficient of friction
Figure 2.1: This is a plot of the expected performance of DLC-DLC contacts and steel-steel contacts.
19
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20
CHAPTER
3
DESIGN
3.1 Theory of Design of Kinematic Coupling
The kinematic coupling chosen was a Maxwell 3 ball and 3 vee-groove design. This
design is symmetric and therefore distributes contact forces evenly over 3 balls and 6 contact
points and simplifies the fabrication process.
Figure 3.1, below, is an image of a 3 ball and 3 vee-groove kinematic coupling.
Figure 3.1: Kinematic coupling with 3 grooves [6].
In order to design for stability, the location of the balls and vee-grooves needed to be
optimized. This was achieved by designing such that the normal to the plane of the contact force
vectors bisect the triangle that was formed by the balls. This is indicated in Figure 3.2 by the
dashed lines. To balance stiffness, the contact force vectors should also intersect the plane where
the ball and plane contact at a 450 angle. This is indicated in Figure 3.2 by the largest inverted
triangle in green. These contact force vectors form a triangle with sides that are tangent to the
coupling diameter such that the coupling diameter is inscribed the triangle. Figure 3.2 shows the
layout for optimal stability for a kinematic coupling with balls located at the vertices of an
equilateral triangle [5].
21
E
ualent ball diameter i l)hcs
Rai1iroove I
L isIstant center
Instant center 1,12
Couping
Triangle
Ba\t,' 2
0(0
Cenrrold
Groove
\
/
_
/
\
RaIV
oove
/
....
Instant
center 23
Figure 3.2: Parameters for optimizing the design of 3 groove kinematic couplings [61.
An analysis of stress and deflection at the contact points utilizing Hertz theory of
elastic contact [7].
This consisted of finding the equivalent radius, Re, of the two contact
surfaces, Equation 3.1. Ri is the radius of the first surface and R2 is the radius of the second
surface.
1
Re
(V- ) + (Then finding the equivalent modulus of elasticity, Ee, Equation 3.2.
Equation 3.1
E is the modulus of
elasticity for the two contact surfaces, respectively and v is Poisson's ratio for each contact
surface.
22
(
Ee =(1
1
_
(1-0
2
~ball)
roove)
+
Eball
Equation 3.2
EgrooveI
Utilizing the equivalent radius and the equivalent modulus of elasticity, the contact radius of the
contact region, a, can be calculated using Equation 3.3, where P is the applied load.
1
Equation 3.3
)
3PRe)
\ 4Ee
Similarly deflection can be calculated using Equation 3.4.
1
Equation 3.4
~16ReElf
Lastly, the contact pressure is calculated using Equation 3.5.
3P
PO =
a2
Equation 3.5
The analysis of stress and deflection along with error motions were analyzed using a
kinematic coupling design spreadsheet designed by Professor Alexander Slocum [8]. The results
from this analysis are summarized in Appendix B.
A stress analysis was also conducted to ensure that the kinematic coupling did not fail
under the applied load. Four stresses were calculated: the shear stress beneath the surface at z =
0.48a, r, the tensile radial stress in the coating at the surface and at the edge, q,
the maximum
tensile radial stress in the coating and at the coating-substrate interface, orr max, and the
maximum tensile radial stress in the coating and at the coating-substrate interface,
rz. The last
three stresses were developed in a paper by Kartik and Culpepper to determine stresses within
hard coatings for a ratio of coating thickness to contact radius less than 0.1 [9].
The shear stress beneath the surface at z = 0.48a, where a is the contact region radius,
23
-0.633
0.903
(i~
097
is the stress that would result in failure of the kinematic coupling. For Poisson's ratio 0.3, the
stress can be calculated by
r = 0. 31po
Equation 3.6
where po is the contact pressure.
The tensile radial stress in the coating at the surface and at the edge can be calculated
by
0.654
o-.r
=
0. 081t-0.03
Fn.3 4 6
(EE)
0.656
Equation 3.7
F
+ 0. 116t0.116 Fn-*,
TE)
E)
\e,(E,/
where t is the thickness of the coating, F is the pre-load, Ee is the equivalent Young's modulus,
Re is the equivalent radius, Ec is the Young's modulus of the coating, and Es is the Young's
modulus of the substrate.
The maximum tensile radial stress in the coating and at the coating-substrate interface
can be calculated by
0 .7 2
o-.,.max = 0. 072-
F.
3 91
(E)
0.609
0.526
(E)
Equation 3.8
-
.8t-0.04F0.347
-008
S0.653
\Fn
E0.591
c)E
E
The maximum tensile radial stress in the coating and at the coating-substrate interface
can be calculated by
24
0.808
4 2 4 FO. 1 92
Orzmax = 0. 204tO.
+ 0. 034tO
3.2
(EL
e
E)
0.394
Es
084
7 4 9 F"
(
n
-0.264
0.916
e)
Equation 3.9
(s
Kinematic Coupling Design
The resulting design of the 3 ball and 3 vee-groove kinematic coupling is shown in
Figure 3.3, Figure 3.4, and Figure 3.5. The distance between the balls in the kinematic coupling
are 4.45 cm apart along the equilateral triangle. The balls are truncated balls from Precision
Balls and are 0.476 cm in diameter. Instead of direct contact to the machined vee-grooves, steel
inserts are glued on with epoxy to the grooves that are machined. This allows for the use of
aluminum instead of steel when machining these parts. The steel inserts are Mitutoyo gauge
blocks, 0.254 cm in thickness.
Figure 3.3: Assembled view of the CAD of the kinematic coupling.
The vee-grooves are 1.195 cm across the top of the grooves. This dimension is larger
than a groove would need to be. This was designed to accommodate the thickness the steel
25
inserts would add to the groove. There are also through holes for mounting to the experimental
setup.
Figure 3.4: Groove side of the kinematic coupling.
The ball side of the kinematic coupling has pockets where the truncated balls are glued
on with epoxy. There are also pockets designed to align with the vee-grooves to ensure that the
steel inserts do not interfere with the ball side of the kinematic coupling.
Figure 3.5: Ball side of the kinematic coupling.
3.3 Diamond-Like Carbon Coatings
Diamond-like carbon (DLC) coatings have been in the works since the 1950s, however
the research for DLC coatings did not boom until the 1980s. This material is an attractive choice
due to its many unique material properties. DLC coatings have: high mechanical strength, high
26
hardness, chemical inertness, excellent thermal conductivity, low thermal expansion, low
friction, and wear resistance. DLC is different from natural diamond because there is no
3
dominant crystalline lattice structure. Instead, they are amorphous and have a mixture of sp and
3
sp2 carbon structures compared to diamond and graphite which only have sp and sp2 carbon
structures respectively [4].
3.3.1 Comparison of DLC Coatings
There are 7 main categories of DLC coatings summarized in Table 3.1. These coatings
can first be separated into two categories, hydrogen-free and hydrogenated. Hydrogen-free
coatings generally have more sp 3 bonds, about 85-95%, in the carbon structure resulting in
3
characteristics similar to diamond. Hydrogenated coatings have less sp bonds, about 30-60% in
hard coatings and 50-80% in softer coatings. Softer coatings have a hardness below 5 GPa and
hard coatings have a hardness ranging from 10-40 GPa. It is important to note as hydrogen
content increases, the microhardness of the coating decreases. Figure 3.6 is a ternary phase
2
3
diagram for DLC coatings. This figure compares the different coatings based on their sp to sp
ratio as well as their hydrogen content [4].
Table 3.1: Summary of the main categories of DLC coatings and their properties.
Tetrahedral
Hydrogenfree
Description
amorphous
carbon
coating
Spp 2
hydrogenfree
amorphous
carbon
coating
containing
hydrogen-
free
amorphous
Hydrogenated
amorphous
carbon
coating
carbon
Tetrahedral
hydrogenated
amorphous
carbon
coating
Metal-
Modified
containing
hydrogenated
hydrogenated
amorphous
amorphous
carbon
carbon
coating
coating
coating
85-95%
85-95%
85-95%
30-60%
30-60%
30-60%
30-60%
0%
0%
0%
10-40%
10-40%
10-40%
10-40%
ratio
Hydrogen
content
27
s
d
UNC
2
Np
3
Figure 3.6: Ternary phase diagram for DLC coatings compared to graphite and diamond. This shows the sp
to sp 2 ratio as well as the hydrogen content of the coating [4].
3.3.2 DLC Coating Selection
Ideally the DLC coating of choice would be an amorphous, tetrahedral carbon coating, taC, or ultrananocrystalline diamond, UNCD. After evaluating the commercial availability, cost,
and lead time, a different coating was chosen. This coating is a hydrogenated amorphous carbon
coating by Sulzer Metco. This coating has a microhardness of 25 GPa, a Rockwell C hardness of
85, a coefficient of friction against steel to be 0.1, and a coating thickness of 1-4 pm. The
method of coating is Plasma-Assisted Chemical Vapour Deposition, PACVD [10].
28
CHAPTER
4
FABRICATION AND ASSEMBLY
4.1 Fabrication of Kinematic Coupling
The kinematic coupling was fabricated using a CNC mill. The material chosen for both
sides of the kinematic coupling was 6061 aluminum for ease of machining. As mentioned
previously, 0.254 cm steel gauge blocks from Mitutoyo were glued on with epoxy to the
machined vee-grooves and 0.476 cm stainless steel truncated balls were glued on with epoxy.
This maintained steel to steel contacts for the kinematic coupling.
The first step in fabricating the groove side of the kinematic coupling was to drill the
through holes with an F drill. After this was completed, a 0.3175 cm end mill was used to face
the part to size and rough out the features. Lastly, a 450 tapered end mill was used to finish the
surface of the vee-grooves. Vee-grooves were machined on both sides of the stock such that
multiple experiments could be conducted. All of this was completed on a CNC mill.
Figure 4.1: Tool path generated in HSM Works compared to the SolidWorks CAD of the vee-grooves.
29
Figure 4.2: Fabricated vee-groove side of the kinematic coupling.
The first step in fabricating the ball side of the kinematic coupling was to use a 0.3175
cm end mill to clear out the material for the features using the pocket feature in HSM Works.
This milled the pockets to avoid interference with the steel inserts as well as the seats for the
truncated end balls. After this was completed, the part was flipped over and three holes were
drilled on the surface. These holes are used for the experimental setup to attach the metrology
block as well as the applied load to the kinematic coupling.
Figure 4.3: Tool path generated in HSM Works compared to the SolidWorks CAD of the ball side.
30
Figure 4.4: Fabricated ball side of the kinematic coupling.
4.2 Assembly
The ball side of the kinematic coupling had pockets milled into the surface as seats for
the truncated balls to sit in. This can be seen in Figure 4.5.
Figure 4.5: Ball side of the kinematic coupling.
The bottom two balls are glued on with epoxy. The top
pocket does not have a ball in it.
The vee-groove side of the kinematic coupling was fly cut before the gauge blocks were
glued onto the vee-grooves. The change in surface finish can be seen in Figure 4.6. The gauge
31
blocks that are glued onto the vee-grooves can be seen in Figure 4.6b. The three through holes
on the kinematic coupling side are used to mount this side of the kinematic coupling to the base
plate seen in Figure 5.2. This side of the kinematic coupling is mounted while the ball side of
the kinematic coupling is moved up and down to load and unload the kinematic coupling.
(a)
(b)
Figure 4.6: Vee-groove side of the kinematic coupling was fly cut before the steel gauge blocks coated with
DLC were glued onto the vee-grooves with epoxy.
32
CHAPTER
5
MEASUREMENT AND TESTING
5.1 Instrumentation and Setup
Two kinematic couplings were assembled for testing. One was assembled for steel to
steel contact testing and the other assembled for DLC to DLC testing. The two sides of the DLC
to DLC contact kinematic coupling is shown in Figure 5.1.
(b)
(a)
Figure 5.1: (a) Vee-groove side of kinematic coupling with DLC coated gauge blocks glued on with epoxy to
the machined vee-grooves. (b) Ball side of kinematic coupling with DLC coating stainless steel balls glued on
with epoxy.
Capacitance probes were used to measure the position of the kinematic coupling. Six
capacitance probes were used to measure six degrees of freedom. Figure 5.2 shows the
experimental setup. The kinematic coupling was loaded with an aluminum block with two steel
blocks attached to either side with super glue shown in Figure 5.3. The load was 2.568 kg. The
33
load also provided the surfaces for the capacitance probes to measure off of.
All of the
capacitance probes were secured with %"-20 nylon soft-tip set screws.
The vee-groove side of the kinematic coupling was mounted to a 1.905 cm thick plate
and the two mounts were also mounted to the base plate.
The top mount, held 3 of the
capacitance probes, was mounted to the two mounts, one holding 1 capacitance probe and the
second holding 2 capacitance probes. The base plate was mounted to an optical table to reduce
vibration. The capacitance probes were connected to a DAQ Device which was connected to a
laptop to collect the data from the capacitance probes.
Figure 5.2: Experimental setup.
34
Figure 5.3: The aluminum block with steel blocks glued on either sides is mounted to the top of the kinematic
coupling, the side with the balls, to load the kinematic coupling.
5.2 Experiments
Two experiments were conducted. The first experiment was steel-steel contacts in the
kinematic coupling and the second experiment was DLC-DLC coated contacts. In each
experiment, the kinematic coupling was uncoupled by lifting the block up and then coupled by
bringing the block down. In order to prevent thermal energy from entering the experimental
setup, gloves were used while lifting the block.
For each experiment the coupling was
disengaged then reengaged. Before data was acquired, the coupling had a 20 second settling
time. The data recorded was the average displacement of 100 capacitance probe readings over 1
second. For each experiment, the kinematic coupling was coupled and uncoupled 100 times.
The measured noise for the capacitance probes was 20 nanometers.
35
This page left intentionally blank.
36
CHAPTER
6
RESULTS
The repeatability of the kinematic coupling was calculated from the data collected. For
each cycle, coupling and decoupling, 100 data points were collected in 1 second and averaged.
This was repeated for 100 cycles for each experiment. Figure 6.1 shows the capacitance probe
arrangement. The position of the kinematic coupling in the x-axis was obtained from the reading
from capacitance probe 4. The position in the y-axis was calculated as the average from the
readings from capacitance probes 5 and 6. The position in the z-axis was calculated as the
average from the readings from capacitance probes 1, 2, and 3. The position in the 0. direction
was calculated from the readings from capacitance probe 2 divided by the distance between
capacitance probe 1 and 2. The position in the Oy direction was calculated from the readings
from the difference between capacitance probes 1 and 3 divided by the distance between
capacitance probes 1 and 3. The position in the 0, direction was calculated from the readings
from the difference between capacitance probes 5 and 6 divided by the distance between
capacitance probes 5 and 6.
37
Figure 6.1: Capacitance probe arrangement on experimental set up.
6.1 Steel-Steel Results
For each experiment, 100 data points were collected for each cycle and averaged. The
coupling was engaged and disengaged 100 times in this experiment. The results for each degree
of freedom was plotted and summarized in Figure 6.2.
38
X Repeatability
806040C,,
C
o
20-
o
-20-
-40-60-80'
0
r
10
r
20
r
30
r
40
r
50
r
60
r
70
r
r
r
80
90
100
r
90
r
100
Cycles
Y Repeatability
806040
C.
L..
0
1
20
Cy-20le
w-40-
-60-80 r
0
r
10
r
r
r
r
r
r
r
20
m0
4Q
w
w
7m
80
Cycles
39
80
Z Repeatability
K
60
40
C:
o
20
E0
o
-20
-40
-60
r
10
-80
r
20
r
30
r
40
r
r
r
r
r
r
50
60
70
80
90
100
90
100
Cycles
OX Repeatability
-
6
U) 4
C:
--
E
-
0
0
-4
-6
0
7. -
10
20
30
40
50
Cycles
40
60
70
80
r
OY
Repeatability
6
U)
2
'0 2
L-
E0
-2
0
-4
-6
0
F
10
r
r
r
r
r
r
F
r
r
20
30
40
50
60
70
80
90
100
Cycles
OZ
Repeatability
6
TA
U)4
C
V0 2
0
E
0
-- 4 H
r
0
10
i*
i*
r
rr
20
30
40
r*
r
50
rr
rr
60
70
_______
rr
rr
80
90
-
-6
r
100
Cycles
Figure 6.2: Summary of results for steel to steel contacts.
The translational repeatability of the kinematic coupling was calculated by taking the
square root of the quantity of the sum of the x displacement squared, y displacement squared,
and z displacement squared. The results are summarized in Figure 6.3.
41
Translational Repeatability
80
60
40
C
o
20-
o
-20
-40<
-60
-80
0
10
r
20
r
30
r
r
r
40
50
60
r
F
r
r
70
80
90
100
Cycles
Figure 6.3: Translational repeatability of kinematic coupling with steel to steel contacts.
The repeatability for one standard deviation and three standard deviation from the mean
for each degree of freedom is summarized in Table 6.1.
Table 6.1: la and 3a for the repeatability measurements for steel-steel.
X (pm)
Y (pm)
Z (pm)
Ox (prad)
la
30.79
17.48
5.75
0.54
0.06
1.46
40.50
3a
92.38
52.46
17.24
1.61
0.19
4.37
121.50
Oy (prad) Oz (prad)
Translational (pm)
6.2 DLC-DLC Results
The same experiment was repeated for DLC to DLC contacts.
degree of freedom was plotted and summarized in Figure 6.4.
42
The results for each
X Repeatability
10r
8
6
4
0
2
E
0
-2
0
L..
-4
In
-6
-8
-'l
0
10
20
30
50
40
60
70
80
90
100
!
r
80
90
100
Cycles
Y Repeatability
10
8
6
C/
4
0
2
E
0
0
-4
-6
-8
A
0
ir
r
r
r
r
r
F
10
20
30
40
50
60
70
Cycles
43
Z Repeatability
10
8
6
4
0
2
E
0
0
-2
-4
-6
-8
-10
0
10
20
30
50
40
60
70
80
90
100
Cycles
ox
Repeatability
1-
-
0.8
-
(U 0.6
0.4f
-
CU
-0
C- 0.20..
0
-0-2-
-0.4
-
-0.6
-1
-
E
'
r
r
r
r
r
F
r
r
r
r
0
10
20
30
40
50
60
70
80
90
100
Cycles
44
OY
Repeatability
1
0.8
UJ)
C 0.6
co
"0.2
0
~-0
-0.2
-0.4
0
-0.6
W -0.8
-1
P
r
r
0
10
20
r
r
r
r
r
30
40
50
60
70
r
r
80
90
100
80
90
100
T
Cycles
OZ
Repeatability
1
0.80.6-
0.4
-
C
-0 0.2CO
0
E
-0.2-
-0.4
-
0 -0.6
-
-0.8
-1
-
w
0
10
20
30
40
50
60
70
Cycles
Figure 6.4: Summary of results for DLC to DLC contacts.
The translational repeatability for the kinematic coupling was calculated for the DLC to
DLC contacts. The results are summarized in Figure 6.5.
45
10-
Translational Repeatability
864-
Cn
0
L-
2-
-2-
0
-4
-80
10
20
30
40
50
60
70
80
90
100
Cycles
Figure 6.5: Repeatability of kinematic coupling with DLC to DLC contacts.
Table 6.2: la and 3a for the repeatability measurements for DLC-DLC.
X (pm)
Y (pm)
Z (pm)
Ox (prad)
Oy (prad)
Oz (prad)
Translational (Pm)
l6
0.55
1.78
0.39
0.04
0.02
0.18
1.87
3a
1.64
5.33
1.17
0.11
0.05
0.55
5.60
The test results conclude that the repeatability of the kinematic coupling with steel-steel
contacts and with DLC-DLC contacts are on the order of tens-of-microns. Based on the results
shown in Figure 2.1, the expected performance for steel-steel contacts are on the order of
hundreds-of-nanometers and tens-of-nanometers for DLC-DLC contacts.
The experimental
results are three orders of magnitude larger than the model. The repeatability of the steel-steel
contact kinematic coupling is on the order of tens-of-microns, about 80 microns.
The
repeatability of the DLC-DLC contact kinematic coupling is on the order of microns.
The
repeatability of the DLC-DLC contacts are at least 1oX better than that of the steel-steel contacts.
It is important to note that the standard deviation for DLC-DLC is one order of magnitude less
than steel-steel. In addition to the repeatability of DLC contacts being 1OX better than the steel
contacts, the deviation from the average value of the repeatability is at least one magnitude less
for DLC contacts.
46
CHAPTER
7
CONCLUSION AND FUTURE WORK
The purpose of this research was to understand the effect of DLC coatings on the
repeatability of kinematic couplings. This coating has the potential to increase the repeatability
of kinematic couplings to the tens-of-nanometers at a low-cost and without the use of lubricants.
This research has created a kinematic coupling repeatable to microns utilizing DLC coatings.
Next steps to further this research is to conduct additional repeatability tests on an optimized
kinematic coupling design and experimental setup. The coupling and decoupling process should
also be automated to allow for more cycles which could verify repeatability as a function of time
and show the wear factor of DLC is magnitudes less than the wear factor of steel.
Future work could incorporate the use of liquid as well as solid lubricants to assess the
performance of kinematic couplings. The performance of DLC coatings vary depending on the
environment thus it is important to understand the affects in that environment before application
[4]. Should this kinematic coupling be utilized in different environments, wet or dry conditions,
additional testing will need to be conducted to understand the performance in these
environments.
A kinematic coupling that is repeatable to microns without the use of lubricants will
allow for more applications of kinematic couplings. Utilizing DLC to attain this achievement
not only achieves this repeatability, but also increases the number of cycles the kinematic
coupling will maintain this repeatability. This results in a longer life of the kinematic coupling
and more reliability thus leading to benefits in cost and quality.
47
REFERENCES
[1]
[2]
[3]
[4]
[5]
[6]
[7]
[8]
[9]
[10]
Culpepper, Martin L, "Design and Application of Compliant Quasi-Kinematic
Couplings," 2000.
MIT Precision Engineering Research Group. "Kinematic Couplings Website."
<<http://kinematiccouplings.org/>>, February 2014.
L. C. Hale, A. H. Slocum, "Optimal design techniques for kinematic couplings,"
PrecisionEngineering,vol. 35, pp. 114-127, 2001.
K. Holmberg, A. Matthews, "Coatings Tribology: Properties, Mechanisms, Techniques
and Applications in Surface Engineering," 2" ed., Oxford, UK: Elsevier, 2009.
Slocum, Alexander. "Design of three-groove kinematic couplings." 1992.
Slocum, Alexander. "Kinematic Couplings: A Review of Design Principles and
Applications." Internal Journal of Machine Tools and Manufacture 50.4 (2010): 310-327.
K.L. Johnson, "Contact Mechanics," I' ed., Great Britain: University Press, Cambridge,
1992.
Slocum, A.H. "Kinematic Coupling Design Spreadsheet." Kinematic Couplings Website:
General Kinematic Coupling Design Tools.
<http://pergatory.mit.edu/kinematiccouplings/index.htm>, February 2014.
Kartik, Culpepper. "Design of Hard Coated Hertzian Contacts for Precision Equipment."
Diamond-Like Coatings from Sulzer
48
APPENDIX
A
DESIGN
A.1 CAD of Kinematic Coupling
The following is a CAD of the kinematic coupling fabricated. There are two sides to the
kinematic coupling. One side consists of the vee-grooves and the other side consists of the balls.
49
A.2 Drawings
The following are the dimensions of the kinematic couplings.
---
-
---
3.00
2.38
-1.74
1.50
1.50
-- 1.26
12O0.0' 3*-
.63k-
0.257 THROUGH
L.J 0.38
TI O.27
3X
.99
2.09
2.51
$1
-4s
-.
/
3.
2.64
50
4E--
Y
R.25
3.00
2.38
1.85
~-1.65
1.50
1.50
1.35
V.
.63
F
.49
1.50
2.192.01 1.96
j
2. 54
3.1
-R.06 4X THROUGH
7
-
0.1883X
I
-~__--
-
R.25 THROUGH
A.3 Process Plans
The fabrication process for each side of the kinematic coupling is summarized in the process
plans.
1 Mill slots for steel insert clearance
2 Mill pockets for balls
3 Flip piece over
3/16" end mill
3/16" end mill
4 Drill hole in center
5 Drill 3 holes for threads
0.5" drill
#7 drill
6 Drill side cutouts for fishing line guide 1/8" drill
1/4-20 tap
7 Tap holes (3)
51
1 Fly cut surface
fly cutter
2 Drill hole in center
3 Drill 3 clearance holes
0.5" drill
F drill
4 Counterbore
Counterbore
tapered end mill
5 Mill vee-grooves
6 Flip over part such that steps can be repeated symmetrically
fly cutter
7 Fly cut surface
8 Counterbore
Counterbore
tapered end mill
9 Mill vee-grooves
10 Fly cut surface
fly cutter
11 Flip over part
12 Fly cut surface
fly cutter
52
APPENDIX
B
KINEMATIC COUPLING DESIGN
SPREADSHEET
This spreadsheet can be accessed at http://pergatory.mit.edu/kinematiccouplings/html/tools.html
[2]. Based on the dimensions of the kinematic coupling, the material selection, and the load
applied, the design can be optimized using this spreadsheet.
-
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A
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APPENDIX
C
MATLAB CODE
The following consists of the MATLAB code used to analyze the data collected from the
capacitance probes. Utilizing the capacitance probes, the repeatability in the six degrees of
freedom was calculated and plotted.
close all
clear all
clC
ImportDLCDLCDataFirstRun
%
a is the triangle side length of the 1-2-3 probes
% a = 0.65 inches
a = 0.01651e6; % microns
% 1 is the half-distance between the 5-6 probes
% 1 = 0.5 inches
1 = 0.0127e6; % micronos
% multiply by 12.5 to change from voltage to microns
DDlCapl = DDFirstCapl*12.500; %microns
DDlCap2 = DDFirstCap2*12.500; %microns
DDlCap3 = DDFirstCap3*12.500; %microns
DDlCap4 = DDFirstCap4*12.500;
DDlCap5 = DDFirstCap5*12.500;
DDlCap6 = DDFirstCap6*12.500;
%microns
%microns
%microns
% angle calculation
ThX = (DDlCap2/a)*10^3; %microradians
ThZ = (1/(l)*(-DD1Cap5+DDlCap6))*10^3;
%microradians
ThY = (1/a * (-DDlCap1+DD1Cap3))*l0^3; %microradians
XAbbe= (1. 75*25400) *sin (ThY*10^-6) ;
YAbbe=(1.75*25400)*sin(ThX*10^-6);
%microns
%microns
X = DDlCap4 - XAbbe; %microns
Y = (DD1Cap5+DDlCap6)/2 - YAbbe; %microns
Z = (DDlCapl+DD1Cap2+DD1Cap3)/3; %microns
%Calculating error
57
XDifference =
YDifference =
ZDifference =
ThXDifference
ThYDifference
ThZDifference
X(l,1)-X(l:end-1);
Y(l,l)-Y(l:end-1);
Z(1,1)-Z(l:end-1);
= ThX(l,l)-ThX(l:end-1);
= ThY(l,l)-ThY(l:end-1);
= ThZ(1,1)-ThZ(1:end-1);
%error bar
e = 10^-3*ones(size(XDifference)); %microns
% X Plots
figure(1)
hold on
plot(XDifference,'ro','markers',8)
errorbar(XDifference,e)
title('X Repeatability','FontSize',24)
xlabel('Cycles','FontSize',18)
ylabel('Error (microns)','FontSize',18)
axis([0 100 -10 10])
hold off
%calculating
standard deviation
Xsigma = std(XDifference)
X3sigma = 3*std(XDifference)
for X
% Y Plots
figure(2)
hold on
plot(YDifference,'ro','markers',8)
errorbar(YDifference,e)
title('Y Repeatability','FontSize',24)
xlabel('Cycles','FontSize',18)
ylabel('Error (microns)','FontSize',18)
axis([0 100 -10 10])
hold off
%calculating
standard deviation
Ysigma = std(YDifference)
Y3sigma = 3*std(YDifference)
for Y
% Z Plots
figure(3)
hold on
plot(ZDifference,'ro','markers',8)
errorbar(ZDifference,e)
title('Z Repeatability','FontSize',24)
xlabel('Cycles','FontSize',18)
ylabel('Error (microns)','FontSize',18)
axis([0 100 -10 10])
hold off
%calculating
standard deviation
Zsigma = std(ZDifference)
Z3sigma = 3*std(ZDifference)
for Z
58
%error bars for theta
etheta = 10*1e-3*ones(size(ThXDifference));
% Theta X Plots
figure(4)
hold on
plot
(ThXDifference, 'ro', 'markers',8)
errorbar(ThXDifference,etheta)
title('\thetaX Repeatability','FontSize',24)
xlabel('Cycles','FontSize',18)
ylabel('Error
(microradians) ','FontSize',18)
axis([0 100 -1.2 1.2])
hold off
%calculating standard deviation for Theta X
ThXsigma = std(ThXDifference)
ThX3sigma = 3*std(ThXDifference)
% Theta Y Plots
figure(5)
hold on
plot(ThYDifference,'ro','markers',8)
errorbar(ThYDifference,etheta)
title('\thetaY Repeatability','FontSize',24)
xlabel('Cycles','FontSize',18)
ylabel ('Error
(microradians) ','FontSize'
,18)
axis([0 100 -1.2 1.2])
hold off
%calculating standard deviation for Theta Y
ThYsigma = std(ThYDifference)
ThY3sigma = 3*std(ThYDifference)
0 Z Plots
figure(6)
hold on
plot
(ThZDifference, 'ro',
'markers',8)
errorbar(ThZDifference,etheta)
title('\theta Z Repeatability','FontSize',24)
xlabel('Cycles','FontSize',18)
ylabel ('Error
(microradians) ','FontSize',18)
axis([0 100 -1.2 1.2])
hold off
%calculating standard deviation for Theta X
ThZsigma = std(ThZDifference)
ThZ3sigma = 3*std(ThZDifference)
% Translational Repeatability
ThreeDRep =
sign(XDifference.*YDifference.*ZDifference).*abs(XDifference.^2+YDifference.^
2+ZDifference.^2).^(1/2);
figure(7)
hold on
59
plot(ThreeDRep,'ro','markersize',8)
errorbar(ThreeDRep,e)
title('Translational Repeatability','FontSize',24)
xlabel('Cycles','FontSize',18)
ylabel('Error (microns)','FontSize',18)
axis([O 100 -10 10])
hold off
%calculating standard deviation for translational
ThreeDsigma = std(ThreeDRep)
ThreeD3sigma = 3*std(ThreeDRep)
60
APPENDIX
D
BILL OF MATERIALS
The following is the bill of materials for fabricating and assembling the kinematic coupling and
the experimental setup.
Pat
Nace
Acstuao Mon
Aluminum blocks
Aluminum racMngl)s
5crews
Aluminum acingla
Aluminum recingle
Sae" block
|Auminu square .
ScS.p a tcraws
Ke-couplin.
Aluminum square
Aluminum square
S5150 gauge blocks
Company
McMaster
McMaster
McMaster
l Mastar
Part Number
Unk to Plan
9140T271
119751K78
h=D*lWW-mser~omLV8975k7B/-rihnid
91251AS42
htin:/www.memastr.oomM1251e542, -rikwfe
hat:jAlww mnmasterwcoMglW4Ot271rihkd7
0975K78
Mastr
18431463
hYAn
Wmcn-alr.coM,1
75BTk7flanni
897158177
9t21A637
Mlaer
McMaster
M~assatr
McMaster
905745
Truncated bails
Precision Balls
187-TB
DLC coang - bals
DLC coatng - Ins a
Expwrftdoln
Fishingline
Superglue
Sular
Sulzer
16437463
19575A31
han:lww~measte~coM8915k7rkh
h2D:/WWwcMssW.omNIK57k24 ftkJ3I
hUniWVwwMef*S1r~CWm1643%63
htng/www.memaslar.comm19575a313erklanz
lnftoce on se2
invoice on 511.862
McMaster
94421313fra
McMaster
7
Purpose
h Vww
825A18
18
Per Quenity
$11.14
2
$22.28
actualor L piece
58.71
2
17A2
mount pieces "a
$7.56
1
$7.58
3 probe lp mount square.
aluminum
base plate
0.7l, 2"Jic
1 probe mount and 2 probe
aluminum
mount
1 2.s3
metrology block
1.2Sthlick. r3' meoigyblock
1'a/4-20 1r
i hold re, probes cm 3p
softip aetscei
$19.31
$71
2
$38.62
2
32.93
129.15
2
$17.42
S65
12915
05"ick, 3Wx3"
$58.10
$29.15
1
2
524.86
16
126"thick. 3"
Bell Side
KC gtiow side
KC
11181 .354. steel ines
.O.l87l"1aml
inemic coupling bails (5
- tuncated balls
for DLC. 3 for atal-dsal
oatO.312
kinemaic
coupling
truncated bails
cot oall mnusmi
kinemaic coupling Inierts
57.20
$7.20
$58.10
$58.30
5447A8
9
$8.70
$15.10
$18.60
Clear nylon AWng
s atsr 0 Itsgnfd
$11.M
lne work load 30 Ba Wo coupling
glue s1.0To alurrinum 4.66
mcmastercom7625a160=r
superglue
klyx
$78.30
590.80
6
12
$223.20
1
$11.56
1
Total
61
Total
actuatrmount
0.765"tk"1A
9751449
Mcastr
McMaster
Description
21a2"x2 aluminum
cuba
alumium 2
14-20 Ilong scre
$4.65
$1.17802
This page left intentionally blank.
62
I
APPENDIX
E
DLC COATING - SULZER METCO
QUOTE
This is the quote from Sulzer Metco for coating 12 steel gauge blocks and 6 truncated stainless
steel balls with DLC.
SULZER
asm.en
mmssne
ftvtNn&
LIV MM
ZM FaaF-R
rn-Z
sLV
Sales QuotaionaNumber: M)M031814-1
Jue WUat
4DLC A
"7 stWommummn s
ft
0.W6
10141"1 4R 20i
Sa-Wd
iUw
0
1A4.3NI
IN 901
C"Me 70
Yft we oim to qwt you te ila"n:
1=l. A)
ADLW
lmS her buwmen euln
2-
A.MTV%
Sbwm Inswru
WDLC A)
0.06? x 0.22' x 1.3
Pin nata
10 -19
B.3L2M amoner tM111cam bell
L.
(p1
smai0 19.40
tI23D
10- 19
20-49
11840
117A0
-
$is"0
IrmUIat ofmar is 1300.W).
oar
you may no mnd mraM tiLat
We wiN be haW to vAnly any fiher Wmmamo
your aircie. wich wo ,r.dvm our prufipeefe cagafa ~On-
M&e McCabe
$43
9
20 - -49
50 -9__
1 -9
Sa Marbit Manew
you N w. 0d ON
VAR
omm
Ia1 W"I "M 9 4111014 *ot
w mas pagewmu1L plame W mad or Fam p0% to
11n"rame aAn
7at
2-20Fame dore any Sis
as eWaflg ma) ewic deasy in Stapuanm as welN.
LAMN 1rns Slndid laimmis 7 buma fts
si lh3un e en~~mamfs
TWAWls WT
1n
iawat ppewegt
as dify ur inus
miN. t0E We me aie ha
3es
am ax WnAMhWKi MY U1:01,301MANR iaibid.
iomin:u
+
,igU m"as amr amaspe 30 0auetma Me
C .)*MIAtaMiT MA4t$7,*1-
w -
(
a.
63
a
'Me
such