Letter of Transmittal 12/15/04

Northrop GrummanBaltimore, MD

Northrop Grumman and Dr. Wilkins:

Attached is a report from Team 8 – Northrop Grumman, explaining what actions we as a team have undertaken this semester, and the results that we achieved. Our purpose this semester has been to present Northrop Grumman with a successful project which satisfies all of their requests.

In order to create better radar systems aboard military ships, Northrop Grumman desired for us to build them a machine which could test the repeatability of non-contacting radio frequency (RF) connections. Since these couplers are a new idea proposed by Northrop it became our responsibility to find out whether or not this idea will work, and if it will be capable of repeatedly making the RF connections. For us to have successfully completed our project in the proper time frame, it was necessary for us to receive a bit of outside assistance. We would like to acknowledge Mr. Robert Drupp, Mr. Scott Hansen, and Mr. John Staehlin, all of Northrop Grumman, for their help throughout the project term. We must also assign recognition to Dr. Dennis Prather, a professor of Electrical Engineering at the University of Delaware, and research assistant Tim Hwang for their help with using the network analyzer. For help with making the plates, we thank Mr. Steven Beard, the machinist in the Mechanical Engineering department. And lastly, we would like to thank Dr. Dick Wilkins, Mechanical Engineering professor of the University of Delaware, for advising us the entire way through our project.

Through the course of this assignment we encountered a small number of limitations which eventually molded our final project. Besides the specified wants and constraints which were relevant to our project, we also encountered limitations involving our lack of Electrical Engineering experience, inexperience with soldering, and the non-uniformity of the couplers. All of these things affected the results of our final project in one way or another, but none presented any problems which were not eventually overcome.

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As a team, we also were successful in performing signal transmission tests, but we understand that both temperature and vibration testing must be carried out in order to validate our work. For these reasons, we would like to recommend to Northrop Grumman to carry on from where we left off, so that these results may ultimately be validated to the fullest extent.

In this report, you will find information pertaining to exactly what our project is about, why we did what we did, and how we validated our decisions. You will find all of the different concepts which were produced from brainstorming ideas and the necessary wants and constraints, which ultimately assisted us in deciding which of these concepts were the best. On top of all this, you will also discover why we decided to employ certain ideas and utilize certain materials over others, especially when referencing our benchmarking section.

A detailed schedule and plan has been included, showing how we utilized our given time to its full potential. It is formatted in such a way so that one may see each individual task which was completed and how long it took to complete. Each task is listed in chronological order, with a complete description of what was necessary to accomplish each distinct task.

We as a team are confident that after reading this report, one will agree that we spent our time successfully, employed and met all wants and constraints, and developed the best possible concept, all while remaining well under the approved budget.

Sincerely,

Team 8:

Scott Kasprzak, Eric Kubecka, Jason Tieste

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RF Coupler Testing SystemRF Coupler Testing System

Northrop Grumman

Scott Kasprzak

Eric Kubecka

Jason Tieste

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5/7/2023

Advised by Dr. Wilkins

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Table of Contents Page

Executive Summary 5

Introduction 6

Wants/Metrics and Constraints 7-10

Concepts: 11-14

Common Modular Frame: 11-12

Winch: 12

Counterweights: 13

Levers: 13-14

Pivot Point on Side Brace, Cable Drawn 13

Pivot Point on Top Edge, Cable Drawn 13-14

Pivot Point on Side Brace, Solid Member 14

Concept Selection: 14-17

Completed Schedule: 18-20

Results and Validation: 20-22

Path Forward: 22

Budget: 22-24

Conclusion: 24

Appendix: 25-61

A-1 Concepts 25-27

A-2 Planning 27-28

A-3 OSHA / Ergonomics 29-36

A-4 UDesign 37-39

A-5 AutoCAD Drawings 40-43

A-6 Material Testing 44-45

A-7 Benchmarking 45-52

A-8 Prototype 53-57

A-9 Analyzer Results 58-61

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Executive Summary:

Project Background:

In order to create better radar systems aboard military ships, Northrop Grumman would like to have a machine which can test the repeatability of non-contacting RF connections. Due to the cost and alignment problems produced by connectors, specially designed couplers have been proposed to make a multitude of RF connections at one time. It has become our goal to help Northrop in developing the test equipment for these new couplers, and to measure the connection repeatability.

Goals and requirements:

For us to begin work on the project, it was necessary to establish Northrop Grumman’s wants and constraints involved with the assignment. Once we had these set up we would be able to come up with our concept ideas for the coupler testing assembly. The metrics are as follows (in order of importance): Alignment/Positioning, Solid Connection, Adaptability, Ease of Use, Cost Effective, Small

Our given constraints include:Materials, Damage-Free, Connectors, Used, Dimensions/Tolerancing, Di-electric materials, Edge Clamping, Vibrations, Large Wire Bend Radius

Concept Selection:

After evaluation using UDesign, benchmarking our ideas and building materials, and talking to our sponsor we came up with a variety of concepts to test the repeatability of the RF connections. We compared our concepts with our wants, factored in the costs, and at a budget of approximately $1852.09 we came up with our final idea, shown below:

Path Forward:

Since we have completed assembling our device and running it through the network analyzer (establishing that signal transmission was successful,) we now plan to hand off our project of to Northrop Grumman. We would like to recommend the continued testing of our device, including more tests using the network analyzer, vibration tests on multiple axes, and finally temperature testing at the high and low extremes. Lastly, we recommend that Northrop make new couplers using both duriods and GPPO connectors.

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Figure 1: Initial Selected Concept Sketch and Isometric AutoCAD Rendering of Concept with Frame

Introduction:

To create better radar systems aboard military ships, Northrop Grumman is developing a new type of radio frequency (RF) coupler for their radar systems. They have asked our group to design and build a device to test these couplers. The test device must be capable of repeatedly connecting and disconnecting these couplers, as well as recording the signal strength after passing through the couplers. These couplers consist of two flat blades, which rest in tubs of dielectric material and send the signal from one blade to the other.

Need for Investigation:

In a radar array, there will be thousands of couplers which are located in two different plates that are bolted

together to induce coupler contact. In order for the tests to be valid, the couplers must come together the same way each time and make complete contact. Also, we must be able to predict what will happen when the radar arrays are taken apart for maintenance. Therefore, the test device must be able to accurately simulate the conditions the couplers will experience during their lifetime (such as misalignment, vibrations, and extreme temperatures). Since this technology is a new development made by Northrop Grumman, there is currently no existing test device.

Goals and Objectives:

The main goal of this device is to accurately bring these flat-faced couplers together repeatedly, without inflicting any damage. It is also necessary to ensure accurate alignment of the couplers and therefore a high-quality signal transmission. At the conclusion of this project we would like to be able to show that our new device is highly superior to the old methods of mating couplers.

Methods and Activities:

In order to show that our device is successful we established a list of customer wants and constraints, of which we needed to meet when designing. These constraints allowed us to clearly define exactly what must be done, and gave us a starting point for our project. Once we developed our mechanism based on these wants and target values, it was necessary for us to implement different testing methods (along with Northrop) to validate our goals and objectives. Between ourselves and Northrop

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Figure 2: Network Analyzer

Figure 3: Exploded Coupler Assembly

Figure 4: Plate and Coupler Cutaway View

the testing methods which were necessary to meet these requirements include vibration testing, temperature testing, signal transmission, and coupler alignment.

Wants/Metrics and Constraints:

After discussing the problem with the engineers at Northrop Grumman, we have developed a list of wants and constraints, which represent their requirements for this test device. From these discussions we have learned the factors that will limit the design of our device. These Constraints are listed below:

Damage free – When testing our device, the couplers must not undergo any serious damage. They cannot be crushed, bent, or broken upon contact.

Dimensions / Tolerances – Because of the couplers connection, our design must utilize accurate tolerances so as to bring the couplers to their correct respective positions and orientations. When closed, the plate gap will be within these dimensions: 0.009" < plate gap < .0715". Our plates must also be designed around the couplers with the right dimensions/tolerances. These were given to us by Northrop as 2’x2’, and 1” thick. The flatness tolerance of the plate surfaces will be .005”.

Materials – For the plates, we must use some type of aluminum, comparable to 6061-T4. The tubs were made of Nickel with a Teflon insert. Also, Northrop will make the metal blades out of copper, to insert between the tubs.

Vibrations– Northrop Grumman wants to use this device for further tests; therefore, they have certain vibration conditions.. The device must meet specs for military shipboard vibrations, and undergo a two hour minimum vibration test.

Connectors Used – We used 3.5mm SMA connectors, and not GPPO connections. These modifications will change the dimensions and clearances given on the inside of the plates, through which the cables will extend. The connectors also had a significant impact on our budget, and the quality of the signal.

Dielectric Materials – We will use a dielectric film between the tubs and copper blades. The dimensions and tolerances for this tape are important because they affect both the spacing of the couplers, and also the location of the tub hole (both of which affect the plates). A second dielectric material was needed to surround the center conductor on the bottom plate. This material was ultra-thin polyester heat shrink tubing.

Edge Clamping – To make sure that the sides of the plates and the edges are kept tight and simulate real world conditions, we used an array of bolts (located 1” from the edge) so that the plates did not move horizontally. Also, the amount of torque which we placed upon each bolt had a significant impact on the plate

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deflection. When assembled, we were able to tweak each bolt individually to achieve the best plate deflection possible (constant deflection with no extreme peaks).

Large Wire Bend Radius – The flexible coaxial cable came out of the back end of each plate. With the cable extruding, we had to account for such things as the frame, and the Network Analyzer that we hooked up to it. We could not bend the cable at a very sharp angle with our significantly affecting the signal. The minimum bend radius, based on the centerline of the cable, was set at .375”.

Wants and Metrics:

To establish the necessary wants and metrics, we asked our sponsors to specify what they wanted from this device. We then role-played ourselves into their position to extrapolate in some areas. The wants and metrics are listed below, in order of importance:

1) Alignment/Positioning:

a. Both plates have the same x and y dimensions (2ft X 2ft). The couplers are located in the same positions in each plate. Therefore, we want our device to bring the plates together so that each side (datum) is aligned. This will insure that each tub is correctly located with respect to its counterpart.b. The couplers are fragile and contain sensitive components. Therefore, we do not want the plates to be brought together at such a high rate of speed that the couplers are dislodged or deformed be the force of impact.

c. The coupler tubs will protrude above the plates. If the plates are contacting each other, the tubs will be damaged; therefore, they must be kept a certain distance apart.

2) Solid Connection: For the couplers to work, they must “contact” each other. Therefore, there is a maximum distance that the plates can be separated at the time of testing.

3) Adaptability:a. The vibration test specs have several requirements that must be met. The equipment must be secured to the vibration table in the same manner as it will be secured in use. However, since our device is only for testing and not for field use, it is only required that it can be strapped to the vibration table. The required test length is a minimum of two hours. Therefore our device must be able to bring together and separate the plates after two hours of shaking. Ideally there will be little or no effect of vibration on each component of our device. In addition, the vibration table can only vibrate in one direction. It is easy to accomplish the x and y axis test; however, our machine must be able to be tipped on its side to test the z-direction.

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4) Ease of use:a. Our test device may be transported to a place that has a network analyzer and it will have to be transported to Northrop Grumman (NG). Also, once it is at NG, it will be moved between different test areas. For these reasons, our device must have as few separate components as possible. Ideally, it will be one self-contained system.

b. NIOSH standards have certain requirements for how much one person can lift based on a given set of boundary conditions. Once that weight limit is exceeded, it will be necessary to have more than one person lifting. Ideally, it should be possible for one person to operate our device.

c. In the field, the plates will rarely be taken apart. Since we are testing repeated attachment, the device must hold the plates stable at every position. This means that when they are disengaged, it should not be required that a person takes one or both of the plates out of the test device.

5) Cost Effective: a. If two concepts are equal in terms of performance, the cheaper concept

will be used.

6) Small: a. Again, because this device has to be transportable, it cannot exceed certain size requirements.

After established our wants and metrics, we needed target values for them, which would allow us to measure whether or not our needs were met. These target values are listed below in Figure 5.

Want Want Description Metric Target Values

1 Alignment / PositioningPosition of the plates with respect to each other

When plates reach the point of contact the datums are coplanar (within .001”)

Movement of the plates together

Plates are brought together at a speed at which no stress is placed on the couplers (i.e. there is no jarring induced by the plates contacting each other)

Plates do not crush the couplers

The device will stop moving the plates when they are no less than .009” from each other

2 Solid Connection Couplers make complete contact

The device will stop moving the plates when they are no less than .009” from each other and no farther away than .0715”

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3 Adaptability Meets requirements for vibration testing Can be strapped to a vibration tableDevice performs in the same manner before and after a 2hr vibration test (no loose components)

Device must be stable in three axes (i.e. can be turned on it’s side)

4 Ease Of Use # of subsystems 1 self contained system

Force applied by operator Force by operator < 36lbs

Stable disengaged rest position

Default rest position is open/disengaged and both plates are still contained in the device

6 Cost EffectiveAll else being equal the cheaper device is preferable Lowest cost to performance ratio

7 Small The overall size of the machine < 3' X 3' Footprint

Concepts and Results:

After some iterations of concept generation and concept development in the previous phases, we realized that there were many different areas in which the concepts could be categorized generally, such as automated or manual.

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Hydraulics

Screw Drive

MotorsChain Drive Clamshell Type

Automated Manual

Counterweights

Lever Lift

WinchLinear MotionHand LiftFigure 6: Possible Concept Areas

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Figure 5: Wants and Metrics Table

The image (right) gives a pictorial representation of just how many available concept areas we investigated. Due to the many categories, we decided we only had to fully develop the concepts that were the most reasonable and applicable, as decided by many rounds of UDesign evaluation. We developed concepts that were farther from the final choice from UDesign iteration 1, such as hydraulics and screw control; however these concept types were too far off the proper mark for us to extract much useful information from evaluation. Therefore, we inferred that the next reasonable step was to generate and develop concepts that were much closer in intent and design to the top choice from round 1 evaluation, in order to optimize our final concept and prototype. By comparing all these similar objects, we determined we would get the best possible concept. Once we narrowed down our generational limitations, we developed the following concepts:

Common Modular Frame:This frame (Figure 7) will be common to all of our concepts, with

minor modifications to accommodate the differences in the concepts. The main features of the frame include 80-20 Inc. extruded profile aluminum bars, which appear in blue and bright green in the figure above. The magenta elements are connection plates, which we bolt to all of the 80-20 members to secure them to one another. The orange element is the bottom plate, which has both guide rods (in red), for general alignment, and short, precision-ground alignment pins (not pictured), for precise alignment once the plates are engaged. It rests on four corner gussets (cyan) that are bolted to the frame and assure positive attachment of the bottom plate without allowing it to shift during testing. The red lifting eyes in the top of the frame are for attachment to a crane or mechanical lift, since this device must be moved for testing, and the device (including the plates at 60 pounds each), will weigh in well over 150 pounds. This frame design is roughly cubic so that the device can be tested on multiple sides in order to comply with the multi-axial vibration testing that Northrop Grumman will perform. For scale reference, the bottom plate is 24”x24”x1”. The small black rectangles on the plate represent the locations where the gaskets/ dummy couplers will be installed, and the blue rectangles (zoomed in, Figure 8) represent the locations where the actual test couplers will be installed. The black cross is the plate center. The test couplers are installed on the diagonal, which is where the worst-case plate deflection will occur. We are testing to see if this deflection affects the behavior of the couplers, so we will place them on the diagonal to observe what happens. The top plate, when installed, will have matching test couplers mounted in its face. The bottom plate has 10 threaded bolt holes per side, on 2” centers, and one threaded bolt hole in the center. This represents the way the system will finally be secured and mounted by the end user.

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Figure 7: Common Modular Frame

Figure 8: Coupler Location

Concept 1: WinchIn this concept, a single speed, one-way cable winch is

attached to the top of the frame. The cable runs from this winch down to some lifting eyes, which are installed in the top plate. When the winch (cyan, to the right) is rotated, the cable is collected on the winch drum and the top plate is lifted. The winch drum has a positive ratchet lock, so once the handle is released, the drum will not spin and allow the cable to unwind. This provides a stable, disengaged rest position for this concept, since the plates are locked in the open position. The schematic on the right indicates how this setup will look.

Concept 2: CounterweightsFor this concept, the four lifting

eyes will be connected in pairs by steel rope, creating two lift points. Each lifting point will be connected to a counterweight sled (in red, left) via a pulley. These counter weights will create a positive lifting force to separate the plates. This concept provides for straight-line lifting of the top plate, since the cables connected to the lifting points run vertically to the pulleys, and then to the counterweight sleds. This concept provides a stable, disengaged rest position, as the counterweights are heavier than the top plate, and will tend to lift it to reach equilibrium.

Concept 3: Levers 3-1: Pivot Point on Side Brace, Cable DrawnThe pivot point for the lever will be halfway down the side support. The four lifting eyes will be connected in pairs by steel rope, then to each other, creating

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Figure 9: Winch Concept

Figure 10: Counterweight Concept

Figure 11: Lever Type 1 ConceptFigure 12: Lever Type 2 Concept

one lift point. This lift point will be connected to the lever via a dual pulley system. When a downward force is applied to the lever, the top plate will rise. The lever will give a mechanical advantage to the user, allowing them to lift the plate with much less force than the plate’s weight force. The magnitude of this advantage, as always, depends on the distance from the pivot point to the plate as compared to the distance from the pivot point to the user-applied force. This setup also maintains straight-line motion of the plate lifting path, which insures that there will be negligible binding of the top plate on the guide rods. This does not have a stable, disengaged rest position, as the lever must be constantly depressed in order to maintain an open position. A separate locking mechanism has to be developed and researched in order to maintain a disengaged rest position, which adds another level of complication to this concept.

3-2: Pivot Point on Top Edge, Cable DrawnThe pivot point for this levered concept will be halfway across on a

horizontal top member of the frame. The lever will be the full length of the frame, and the lifting cable will be attached to the center of the lever. The lever will give a mechanical advantage to the user, allowing the user to lift with less force than the weight force of the plate. This concept does not provide true straight-line lifting motion; when the lever is lifted, the attachment point of the cable must shift laterally to describe an arc about the lever’s pivot point. This does not have a stable, disengaged rest position without an external stop block, as the lever must stay lifted to a certain position in order for the plates to remain disengaged.

3-3: Pivot Point on Side Brace, Solid MemberThe pivot point on this concept is also on the vertical

side brace of the frame, but in a different manner than concept 3-1. This lever extends into the inner part of the frame, and has a rigid, hinged connecting member to the top of the plate. When the outer end of this lever is pushed downwards, the plate will lift. As with all of the other levers, this will provide a mechanical advantage to the user. This concept does not provide true straight-line motion, as the lever end attached to the plate must describe an arc about the lever attachment point, and, therefore, must move laterally as well as vertically when moving. This concept does not have a stable, disengaged rest position, as the lever must remain depressed in order for the plates to remain disengaged. A separate locking mechanism has to be developed and researched in order to maintain a disengaged rest position, which adds another level of complication to this concept.

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Figure 13: Lever Type 3 Concept

Concept Selection:

To decide which concept was the best, we compared each of them by having a person lift one plate off of the other (this is our benchmark) based on how each one met our metrics and target values. We started with this because it is the most basic, simple way of accomplishing our task. In order to compare our concepts with respect to ease of use and size, we need to calculate how much weight the operator would need to move as well as how much space the lever arms would require. To do this, we used the specifications from the National Institue of Occupational Safety and Health (NIOSH). NIOSH makes recommendations for standards to the Occupational Safety and Health Administration (OSHA). Based on the lifting conditions- such as height of work surface, size of object, distance traveled and several other parameters- we found out exactly how much weight could be lifted for each concept (see Appendix A-3 for detailed description and calculations). Then using basic static equations we found how long each lever arm needed to be (see Appendix A-3 for detailed calculations). The UDesign spreadsheet for our concept selection can be seen in Appendix A-4.

The top metric is respective plate position. We want the plates to be aligned with each other at the point of contact for each repetition. We used guide rods and alignment pins to ensure that each of the datums are aligned for each cycle. As a result, the concept that was used would not have changed how the plates align when closed so each concept received a same a benchmark score.

The second metric is coupler contact. We need the plates to be close enough that each coupler makes contact and far enough away that the couplers are not being crushed. In order to ensure coupler contact, there is a set of rubber gaskets that allows for some displacement of the couplers. Therefore, if one coupler is higher

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Figure 14 : Concept Rating Scheme

Figure 15 : Rated Concept Chart

off the plate than another, its gaskets will compress allowing the other couplers to make contact. Also, there are precision washers at each bolt location which stop the plates from coming too close together. This protects the couplers from being crushed. Again, this feature is common for all concepts, so each was given a same as benchmark score.

The next metric is plate speed. We wanted the movement of the plates to be “in control”, meaning they did not move so fast that the couplers were dislodged or impact each other with enough force to damage the couplers. If one person lifted the top plate, he or she would be dealing with sixty plus pounds and would not be able to accurately control the movement of the top plate. Each concept reduces the amount of weight that the user has to work with, thus allowing for more control of plate speed. For this reason, each concept received a better than benchmark score.

The next metric is meeting vibration test requirements. The benchmark consists of plates bolted together with no additional parts, which is good enough for the vibration test. Each of our concepts has some type of locking device so when the blots are bolted together, it prevents movement of and moving parts (i.e. winch handle, lever arms and counterweight sliders). For this reason, each concept received a same as benchmark score.

Next is number of subsystems. Our device needs to be transportable to get it from here to Northrop, as well as to each of the test areas in Northrop. Also, it needs to be self-contained. If there were any components of the device that protruded from the sides, they would cause a problem for safety and transportability. The winch is located on top of the frame so there is nothing sticking out of the side of the frame; therefore, this concept received a same as benchmark score. Although the counterweights are on sliders on the side of the frame, which would have stuck out of the side of the frame, they would have only protruded a few inches and would not have been a serious problem. Therefore, the concept received a same as benchmark score. After performing calculations for the length of the lever arms for each lever concept (see Appendix A-3 for those calculations), we found that lever concept 1 and lever concept 3 would have such long lever arms that they would stick out of the frame as much as a foot. This is unacceptable, so each received a worse than benchmark score. Lever concept 2 did not need such a long lever arm, so it received a same as benchmark score.

The next metric is cost to performance ratio. This means that, whichever concept does what we need it to and is cheaper will be the best. The benchmark does not require any frame and every other concept does, so each concept will be more expensive than the benchmark. For this reason, each concept received a worse that benchmark score.

Next is machine size. The fact that our device will be used for different tests, it cannot be so large that Northrop’s test facilities cannot accommodate it. The benchmark will only be as big as the two plates. The frame that we made has the same footprint as the plates, so any concept that had components sticking out of the frame would not be as functional. Again, the concepts with lever arms that stuck out of the frame (lever 1 and lever 3) received a lower than benchmark score. Every other concept-winch, counterweights and lever 2-received a same as benchmark score.

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The next metric is force applied by the operator. Our device was supposed to make it easier for someone to put the plates together and take them apart. Each concept makes the load seen by the operator much less than the benchmark, which is sixty pounds, so each received a better than benchmark score.

The last metric is stable disengaged rest position. The operator should not have to remove a plate and put it aside at any point during the test. Also, the system should allow the rest position of the top plate to be raised off of the bottom plate. The winch and the counterweights provide the restriction needed to hold the top plate in the air, so the concept received a better than benchmark. Each of the lever concepts required some additional support of locking system, so they received a same as benchmark score.

With all of these scores tabulated in UDesign, we did not have one concept that was clearly better than the next. We also realized that for several of the metrics, each concept was better than the benchmark, but this did not show how the concepts compared to each other. Therefore, we performed a second UDesign analysis with our winch concept as the benchmark, and compared it with the two concepts that had the closest score from the previous UDesign (the counterweights and lever 2).

This did not affect first plate position and coupler contact, so each concept received a same as benchmark score in those two areas.

Next was controllable plate speed. The winch had a built in control because the handle could be rotated as slowly as desired. The lever could also be raised or lowered as slowly as desired, so it received a same as benchmark score. The counter weights required a person to be pushing down on the top plate to make it move down. This requirement created difficulty in controlling the movement speed of the plate. For this reason, the counterweight concept received a worse than benchmark score.

Each concept met the requirements for vibration testing and none could do any better than another, so each concept received a same as benchmark score.

Each concept was self-contained with nothing sticking out of the device, so each received a same as benchmark score.

Each concept had the same frame; therefore, the cost was the same for each. The counterweights were much more expensive than the winch, so it received a

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Figure 16 : Udesign Sample – Concept Selection Iteration

worse than benchmark score. The lever required a few inexpensive components that were about the same cost as the winch, so that concept received a same as benchmark score.

Again, all three systems are the same size, so each concept received a same as benchmark score.

The calculated force applied by the operator for the winch concept was about 5 lbs. While each of the other concepts had lower force than our requirements, they were both higher than the winch, so they received a worse than benchmark score.

The winch held the top plate up in the air so it had a stable disengaged rest position. The counterweights were heavier than the plate, so it also had a stable disengaged rest position. For this reason, it received a same as benchmark score. The lever concept required an upward lifting force to raise the top plate so it did not have a stable disengaged rest position. Therefore, it received a worse than benchmark score.

After performing this iteration for our concept selection, it was clear that the winch concept was much better than any of the other concepts.

Completed Schedule:

We originally started our plan by working backwards from the due date of our Senior Design Project. We looked at the dates of when Phase II and Phase III would be due, and from there we established what task would need to be completed and by what specific date. Since we have now completed all these tasks (with the exception of Power Point Presentation) we can break each task down more specifically and analyze exactly what was complete when, step by step.

After we spent a good amount of time conversing with Northrop Grumman and getting an idea of what our project would entail, we soon realized we would need

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Figure 17 : Completed Schedule

to begin placing orders for our materials to be delivered. We assumed that many of our supplies would not arrive on time, or we would receive the wrong items, or faulty equipment. We therefore allotted extra time for ordering/delivering of these materials.

Samples of the polyester heat-shrink tubing were given to us by Northrop. We were handed a variety of tubing with different diameters, and thicknesses (not to mention mechanical properties) to get an idea of which one would best fit our needs. We hit a snag when we found out that there was a minimum order of one-hundred feet, which would prove to be way too costly. Fortunately after a bit of consulting with sales we were able to receive a two foot sample which was more than enough for our needs. Choosing the proper tubing did not take much time at all since we knew exactly what we were looking for, therefore we allotted approximately one day for this particular task.

Our gasket materials were ordered from mcmastercarr.com so we would be able to compare the samples with one another. In order for us to decide which material to go with we had to test it, for all we knew was a given thickness. The way we did this was by cutting out a number of the sample gaskets to proper shape, and placed them into the Instron machine to produce force vs. deflection curves. (explained thoroughly in gasket testing section of report). Based off the force and durometer we were finally able to pick the proper gasket materials for both inside and outside of the tubs. Cutting and testing these gaskets eventually ended up taking about one full week.

Originally Northrop stated they would machine the plates for us on site. However a few monetary and time issues arose with this and the task was handed over for us to complete at UD. Before we even began to think about making the plates, we first decided to compare all of the dimensions which were given to us with corresponding tolerances which we received from an expert on the subject. We then took these dimensions and tolerances and created all the proper AutoCAD drawings which were then shown to the U of D machine shop to be approved. The plate drawings took about 4 days time to complete, and then we only need to present them to the shop (one day).

In due course we finally got to machining the plates, which took us a week to complete. Since the same bolt pattern was repeated on both plates, we were able to utilize the C&C mill to program our pattern once, and just repeat it upon both plates. It was necessary for us to rotate each plate while machining so we could drill all the holes, since the mill arm depth only has a 14inch reach. We also need to cut out the pockets, proper holes for the guide dowels, and alignment pins, and finally for the lifting eyes. Once the basic drilling was done we needed to both countersink and tap all the proper holes. Lastly, we smoothed down the edges, getting rid of any hazardous metal shavings, and finally cleaned off the plates, and blew out the holes.All this time we needed to wait for Northrop to finalize the tub dimensions, so they could finally machine the tubs and send them out to us. They were completed by the 1st of December, which allowed us about 2 weeks to get everything put together. We gave Northrop well over a month for both these two tasks that way they would have some room for mistakes incase something went wrong. We made sure we did this also since we were not in control over the situation.

19

Putting the 80/20 aluminum framing materials was very simple and was quickly completed. However, much more went into the overall assembly of the entire device. For one we first needed to both level the support brackets for the plates, and then secure the plates in these brackets so that they were centered within the frame. Then it was necessary for us to attach the eyehooks to the plates, the cables to both the eyehooks and the lead cable (which extends from the crank arm), secure them with the cable clamps, and then attach the lead cable to the crank arm. Once all this was completed, we needed to make a support bracket so the crank arm could be fastened to the 80/20 framing material, that way the plate would not shift it when being raised. We also had to ensure that the crank arm was strategically located over the center of the plates, so it would raise the plate evenly on both sides. Lastly, the drilling of the holes for the safety pins, and insertion of the pins were completed. Altogether this was approximately a 3 week process, for the device assembly.

Finally, we recently just tested our machine, using the network analyzer in the Electrical Engineering Department, in Evans Hall. This testing took us a day to complete.

Lastly, we needed to finalize and practice our Phase III presentation and present it to Northrop Grumman. Then we were finally able to present our path forward to them and request further testing.

Discussion of Results:Testing and Validation:

Once we completed the assembly and construction of our prototype (Pictures of the completed device can be seen in Appendix A-8, our validation plan involved testing. In order to validate our prototype, we tested our device using the network analyzer in the Electrical Engineering department. Testing comprised of the following steps:1.) Tighten bolts located around plate

perimeter (and 1 in center).2.) Connect couplers to network

analyzer.3.) Run S21 parameter testing (signal

going through top plate, out of bottom plate).

4.) Save data to disk5.) Disconnect coupler from network

analyzer.6.) Detach bolts and raise plates7.) Repeat Process

20

(Refer to Appendix to see our results from Network Analyzer Testing).The graph of the signal for coupler 2 (Figure 18) shows that the signal from trial one and trial 4 is virtually the same. The graph of the signal for coupler 3 (Figure 18) shows that the signal from trials two through five is virtually the same. So, while some of the results are not very informative, we were able to collect enough data to show that mechanical wear should not be a problem for these coupler. However, we do recommend that further testing be done. Although the results vary a bit from figure to figure, we were still able to show that sending the signal was possible. The difference in the graphs is most likely a factor of human error while soldering, or a weak connection somewhere between the tubs and center conductor. While there was variation between the results for each coupler we were able to get enough information to show that repeated wear from maintenance cycles will not affect signal strength.

The Frame:

Since vibration was one of our constraints, when we decided upon choosing a framing material we based our decisions strongly upon this. After researching a number of different materials, including plastics such as PVC, and some metal materials, we decided to use 80/20 aluminum framing materials. Seeing that 80/20 gave us a versatile amount of materials to work with, and that it was easily adaptable to any of the other catalog materials, we decided that it would definitely work the best. All of the 80/20 materials are vibration proof, and all of the t-slotted structural extrusions contain a drop lock feature, so that when tightened with a bolt, they become perfectly flat (the structural members are built at a 2 degree decline, and when tightened this decline will converge on 0 degrees.) Also, the nut and bolt combinations, which we will order for our frame come pre-loaded, which ensures a vibration proof connection.

Our test plan for the 80/20 frame includes handing off our device to Northrop to allow them to continue testing. They will place our frame on a vibration test table in order to verify that the device does will not fall apart in actual conditions. They will also subject our device to extreme temperature tests, as additional validation.

Our final frame design, including the 80/20 aluminum framing material, along with the winch was validate during concept selection. We used UDesign, iterating a number of times, and re-establishing our concept benchmark until we concluded that the winch idea was the best concept, based on our target values and off of our metrics.

So how did our device meet each one of our wants and metrics?

First, plate alignment is guaranteed by the guide rods and alignment pins that are located in the plate. These align the plates every time they come together. Further,

21

Figure 19: Drop-Lock

Figure 18 : Test Results – Coupler 2 (Top) Coupler 3 (Bottom)

each time we opened and closed the plates every bolt was lined up with its respective hole and there was successful transmission of the signal through each coupler (see Appendix A-9 for proof of signal transmission). For plate movement speed, the winch reduced the amount of weight seen by the operator to a small enough amount that it was easy to control the movement of the top plate. In addition there was a gear box which meant the movement speed by the operator was reduced before reaching the plate. Upon visual inspection after our tests the couplers were not damaged so the plates did not crush the couplers. There were precision shims between the plates which guaranteed the plates were not to close together and the bolts guaranteed that the plates weren’t too far apart. Although we could not perform a vibration test we designed the frame to be very open which will allow it to be bolted to a vibration table. In addition the frame was as stable on its side as when it is in its normal position, thus it can be vibration tested on all three axis. Our device is made of one subsystem and as previously stated the force by the operator is only five pounds which is much lower than our target value of thirty six pounds. The winch has a lock which is engaged when the plate is raised the creating a stable disengaged rest position. And finally the footprint of our device is only 2ft by 2ft which is under our target value of 3ft by 3ft.

Path Forward:

From this point on, it will be necessary for us to present to Northrop all of the results which we acquired from our testing. We will recommend to them the continued testing of the following:

-signal strength-plate alignment and deflection-vibration testing-temperature testing

We would like Northrop to carry on from where we left off, with the testing of the signal strength to obtain information on whether or not the signal becomes weakened after time. Due to things such as repeated use, corrosion, and vibration, through the course of time, the signal may lose some of its transmission.After repeated use, there may also be some unnecessary wear on the couplers which may affect both the plate alignment and deflection. We would ask Northrop to be aware of this, and perform maintenance as needed. Ever since our first meeting Northrop indicated to us that they would like to perform vibrations tests on our device to guarantee that our design would be feasible in real world applications. Due to the fact that we have modeled a large portion of our project design around this, we would recommend Northrop Grumman utilize their vibration table, located on site at their Baltimore facility. Lastly, we believe that temperature testing will be a very important task for them to undertake, to make certain none of the parts will become weakened or damaged under extreme conditions. Lastly, we recommend that Northrop make new couplers using both duriods and GPPO connectors. After they have completed all these tasks, we would

22

ask them to make a decision on whether or not our mechanism seems appropriate to be put to actual use.

Budget:

After tallying all of our costs via receipts, from the materials that were required to assemble our device, we ended up with a final cost of $1852.09. We feel that this price is very reasonable when compared to our other options. If we had gone with an automated approach, we would have been spending close to $1,000.00 dollars for motors alone. The majority of the budget comes from the cost of the aluminum plates as provided by Alcoa, the 80/20 framing costs, and the weights. Since we machined the plates ourselves, we saved a large sum of money for Northrop Grumman. Shipping and handling charges have also been included in the budget report shown:

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24

Figure 20: Detailed Budget Breakdown

Conclusion:

Upon completion of our project, we as a team realized the importance of first establishing our customer’s wants and constraints, and then using UDesign to assign value to these wants. We also learned how efficiently employing UDesign’s concept selection can help one to decide which of their concepts would best fit the necessary requirements. Establishing our problem definition and project background early on, we realized was also a vital part of the design process. We had to make sure we had a firm grasp on exactly what our project is and where we need to go with it.

Throughout the duration of the design process, we also realized the importance of establishing a well-built schedule, along with a number of back up plans. When something possibly goes wrong, as it did for us a number of times, it was extremely handy to have our back up plans ready, and know exactly where to go, from the last place we left off. Validating our report was an extremely important part of our project as well. Being able to test our device, and prove that it worked shows that we carefully though out each step, and planned ahead. However, even if it hadn’t worked, the important thing was that in the end we still satisfied Northrop requirements, and met all the design criteria for our project.

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Figure 21: Budget Allocation Percentages

Appendix

A-1: Concepts

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Figure A1.1: Common Modular Frame

27

Figure A1.2: Winch Concept Figure A1.3: Counterweight Concept

Figure A1.4: Lever Type 1 Concept Figure A1.5: Lever Type 2 Concept

A-2: Planning

  September     October     November     December  Wk 1

Wk 2

Wk 3

Wk 4

Wk 1

Wk 2

Wk 3

Wk 4

Wk 1

Wk 2

Wk 3

Wk 4

Wk 1

Wk 2

Wk 3

Wk 4

Problem Definition

Project Selection, Initial Visit

at Sponsor

Problem Solving Methods

Benchmarking; Team Norms; Sponsor/Team/Advisor Meetings; UDesign for Wants/Constraints, Metrics/Target Values; Concept Generation; Concept Selection; Refine

Concepts; Phase ½ Reports/Presentations

Resource Management

Cost Analysis – Project & Prototype; Time Management – Meetings, Memos, and Professional Consultation  

Constructing Prototype Gather/Order Materials; Construct Prototype  

Testing, Evaluation, and Final

Presentation

Test Prototype; Evaluate Test Results/ Draw Conclusions;

Determine Success or

Failure; Deliver Final

Presentation

 

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Figure A1.6: Lever Type 3 Concept

Figure A2.1: General Plan

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Figu

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2.2:

Gan

tt C

hart

A-3: OSHA and Ergonomics

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Figure A3.1: Ergonomics Variable Definition

31

Figure A3.2: Ergonomics Calculation Sheet

Frequency Multiplier Table (FM)

Work Duration Frequency < 1 Hour < 2 Hours < 8 Hours Lifts/min             (F): V<30 V>30 V<30 V>30 V<30 V>30

0.2 1.00 1.00 0.95 0.95 0.85 0.850.5 0.97 0.97 0.92 0.92 0.81 0.81

1 0.94 0.94 0.88 0.88 0.75 0.752 0.91 0.91 0.84 0.84 0.65 0.653 0.88 0.88 0.79 0.79 0.55 0.554 0.84 0.84 0.72 0.72 0.45 0.455 0.80 0.80 0.60 0.60 0.35 0.356 0.75 0.75 0.50 0.50 0.27 0.277 0.70 0.70 0.42 0.42 0.22 0.228 0.60 0.60 0.35 0.35 0.18 0.189 0.52 0.52 0.30 0.30 0.00 0.15

10 0.45 0.45 0.26 0.26 0.00 0.1311 0.41 0.41 0.00 0.23 0.00 0.0012 0.37 0.37 0.00 0.21 0.00 0.0013 0.00 0.34 0.00 0.00 0.00 0.0014 0.00 0.31 0.00 0.00 0.00 0.0015 0.00 0.28 0.00 0.00 0.00 0.00

>15 0.00 0.00 0.00 0.00 0.00 0.00

+ Values of V are in inches: For lifting less frequently than once per 5 minutes, set F = 0.2 lifts/minute.

Hand-to-Container Coupling Classification (CM)

Coupling V<30 V>30Good 1.00 1.00Fair 0.95 1.00Poor 0.90 0.90

Good       Fair   Poor  1. For containers   1. For containers of 1. Containers of of optimal design optimal design, a less than optimal such as some boxes "Fair" hand-to- design or loose crates, etc., a object coupling parts or irregular "Good" hand-to would be defined as objects that are object coupling handles or hand- bulky, hard to would be defined as hold cut-outs of less handle, or have handles or hand- than optimal design sharp edges hold cut-outs of           optimal design            2. For loose parts or irregular

2. For containers of 2. Lifting non-rigid

32

Figure A3.3: Ergonomics Calculations Table

objects, which are not usually optimal design with no bags (i.e., bags containerized, such as handles or hand-hold that sag in the castings, stock, and supply cut-outs or for loose middle). materials, a "Good" hand-to- parts or irregular     object coupling would be objects, a "Fair" hand     defined as a comfortable grip -to-object coupling is     in which the hand can be defined as a grip in     easily wrapped around the which the hand can be     object       flexed about 90 degrees    

33

34

Figure A3.4: Calculations for Winch Concept

35

Figure A3.5: Calculations for Counterweights Concept

36

Figure A3.6: Calculations for Lever Type 1 Concept

37

Figure A3.7: Calculations for Lever Type 2 Concept

38

Figure A3.8: Calculations for Lever Type 3 Concept

A-4: UDesign

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Figure A4.1: UDesign – Customers and Customer Wants

Figure A4.1: UDesign – Benchmarking and Metrics Sheet

Figure A4.2: UDesign – Top Customer Wants

Figu

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4.3:

UD

esig

n –

Met

rics

40

41

Figure A4.4: UDesign – Concept Evaluation

A-5: AutoCAD Drawings

42

43

44

45

46

A-6: Material Testing

Gasket Testing:

We cut out several gaskets in the proper shape, but in different materials of different durometer. We placed these gaskets in the Instron machine to produce force vs. deflection curves to determine how durometer rating applied to these curves. We found out that the higher the durometer, the larger the force required to impart the same compression distance. We also noted that material does not matter much, since different materials with the same durometer behaved in the same way. We used the results from this testing to choose our gasket durometer. We chose the 30A durometer neoprene for the gasket, which will be inside the tub, and the 55A santoprene for the gasket that will be outside the tub.

Plate Model Testing:

We understood that the plates would deflect the most in the areas farthest from the supports (bolts). This was especially applicable, since we had a distributed load across the breadth of the plate. Therefore, we manufactured and tested quarter-scale plates. On these 6”x6” plates, we drew out a grid representing the scaled positions of where the couplers would be in the real

plates. We checked the plates for flatness once they were bolted together using a dial indicator. We then placed a full-sheet gasket between the plates, and measured the deflection caused by the gasket in the flattest quadrant. We graphed these results in Excel to get a perceptible, visual idea of how the deflection varied on the plate due to the loading of the sandwiched gasket. We used the results from this test to determine the optimal positions for our test couplers. We placed our four couplers along the diagonal from the corner to the center bolt, since this line is where the worst-case deflection occurs.

47

Figure A6.1: Test Gaskets

Figure A6.2: Gasket Installed on ¼ Scale Plates

Figure A6.3: ¼ Scale Plates with Dial

Indicator

A-7: Benchmarking

Benchmarking is a vital part of the design process to circumvent the possibility of designing something that has previously been designed. Currently there are no devices that are specifically design for testing these new types of couplers. Therefore, we could not benchmark any specific competitors or existing machines. We were able to find machines that accomplished the same task of bring together and separating two surfaces. We also looked at ways to build a simple device rather than buy a different one and modify it for our purposes. Appendix A-2 there is a detailed list of the specific items we found.

Throughout the duration of our project we gained new and vital information which also served as a form of benchmarking and helped to shape our design ideas. OSHA regulations came into play in a number of factors throughout our design process, including the height of the workbench, and the lifting capacity of an individual. After researching what the exact requirements were for both, we calculated that one person can only lift about 36 pounds (see Appendix A-3 for calculations), which is much less than the weight of one plate (which is 60 lbs).

Lifting and lowering systems:

In order to find a proper way in which to move our plates together and apart, in an effective manner, we looked at a variety of lifting and lowering systems. We researched everything from levers, to hoist systems, to winches, to motors (via the use of pulleys and cables), and a number of others.

Levers:

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Figure A6.4: Graph of Deflection Due to Gasket Compression. All Measurements in mm/100

In lever terminology there are three different classes of levers in which to go with; First class, Second class, or Third Class levers. The difference between which one is dependent upon the fulcrum included, and the location of the Force applied. In order to lift up our plates, the use of a lever located on the opposite side of the 20/20 framing material, and included pulleys, seemed to be a possibility. Since the lever could be worked manually, it would be a very cheap yet convenient apparatus to go with.

Hoist Systems:

Another way, in which to lift and lower objects effectively, was the use of a vacuum-assisted mechanism. VacuMove is ideal for lifting almost anything weighing up to 160 kg quickly, efficiently and safely. However, due to the unreasonable price and shear size of the vacuum-assisted device, VacuMove and similar products seemed very unreasonable for our applications.

The winch and pulley assembly seemed to be a very applicable system to use for our purposes. Since we would only need a device to lift 60 lbs of weights due to OSHA regulations (see Appendix A-3), a winch and pulley system seemed very reasonable.

We therefore decided to research both manual and electric winches.

49

Figure A7.1: Lever Classes

Figure A7.2: Commercial Vacuum Hoist

Figure A7.3: Electric Person Hoist

50

Figure A7.4: Sample of Manual Winches in Online Catalog (www.mcmaster.com)

Figure A7.5: Sample of Electric Winches in Online Catalog (www.mcmaster.com)

Pulleys:

We looked at a variety of pulleys ranging from rope and cable pulleys, aluminum and cast iron, mounted and un-mounted, and an assortment of others. In particular, for our uses in this project, we decided to concentrate on looking at the mounted aluminum pulleys. Since our apparatus will use stand alone uprights (80/20 material) supporting our coupler banks at the base, we decided that the pulleys can be mounted atop of the 80/20 aluminum frame. Our assembly will need to consist of at least two cables or ropes, and three pulleys (one of which will be like that shown in Fig A7.8)

Above highlighted in yellow is the Aluminum hub pulley. With a working load of 560 lbs and an individual price of $8.53 we decided that this may be a strong contender.

This is an example of a rope pulley. With a little intuition, we decided that if we can flip this apparatus upside down and use it to pull up our top plate assembly, it might be just what we need. Once we decide what angle our rope will be positioned at, we will need to use the Angle Multiplier Chart to calculate the load on each individual block. We have calculated the mass of the top aluminum plate to be approximately 55 lbs, and not to exceed 100lbs. This will be the total load taken by the single rope pulley, and we must decide exactly which one to pick.

Websites to refer to:www.thomasregister.com/

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Figure A7.6: Sample of Pulleys in Online Catalog (www.mcmaster.com)

Figure A7.7: Pulley Usage

www.mcmaster.com/ www.mrgasket.com/pdf/EngineComponents.pdf http://www.conveyerail.com/about.htm http://www.flexibleassembly.com/HandlingSystems.php

Compression Machines: Aside from Instron testing equipment there was not a large quantity of other machines which would perform to the exact specifications that we were looking for. The closest matches were basic molding presses, which would be fairly difficult to control the accuracy of.

Molding presses work very similar to the Instron equipment, in that they are run by hydraulics which force the top plate to compress downwards toward the bottom plate. These machines however are meant for being used repeatedly under short intervals of time, and are not very easy to control force-wise.

Websites to refer to:www.gluco.com www.cplink.net www.santecindia.com/compression-moudling-presses.html

52

Figure A7.8: Instron Compression/ Tension

Tester Figure A7.9: Basic Molding Press

Figure A7.10: Basic Molding Press

The cable we chose to use in our pulley system is that of plain steel. We will need no more than 6 feet, and it can be order in increments of 10, 50, 100, 200, 300 or over 5,000. At $0.63 per foot, and a breaking strength of 3,100 lbs this should meet all our requirements.

Metal to Rubber Adhesives:

One of Northrop Grumman’s wants was that we somehow adhere the center conductor to the backside of the copper blade. The original plan was to just solder them together, however due to the tight working spaces, and other limitations this seemed to be an impossibility. Therefore, we were asked to investigate a way in which to efficiently bond both of these items together. After investigating a number of different bonding agents, including mostly epoxys, and some spray adhesives, we found PARBOND® Epoxy Adhesives, to be the most probable. Parabond 150, and Parabond 300 both contain excellent adhesion to a wide variety of surfaces including wood, any hard and soft wood, Metals, Ceramics, Concrete, Plastics, Rubbers, and other materials. They are ideal for permanent assemblies and repairs, and can cure in either a 5 minute working time for the Parabond 150, or a 30 minute working time for Parabond 300. Both of these curing speeds are reasonable enough, to give us enough time to position the assembly correctly, and at the same time not take up a full day to accomplish.

Websites to refer to:

http://www.crestnetsales.com/metalbonding.htm

http://www.dymax.com/products/metal/metal.asp

http://www.ok2spray.com/MP.html

http://www.parsonadhesives.com/?OVRAW=metal%20adhesives&OVKEY=metal%20adhesive&OVMTC=standard

PARBOND® Epoxy AdhesivesPARBOND offers a complete line of one and two part epoxy adhesives for structural bonding, potting, and encapsulating applications.PARSON line of epoxy adhesives designed to cover wide range of application-specific products by providing following features and benefits: • Excellent bond strength • Lower cost • Excellent durability • Good resistance to high temperature, humidity and chemicals• Custom formulations

53

Figure A7.11: Sample Cable Selection

Following are our standard products. Custom formulations and packaging are available upon request.

Product

Color

Viscosity at

25° C cps

Work

Life(min

)

Mix Ratio

by vol.

OverlapShear

Strength

(psi)

Hardness

(Shore)

Application

150 Clear Resin - 15000

Hardener - 12000

5 1:1 2500-3000

80 Fast curing epoxy with a 5-minute worklife. General-purpose bonding applications.

300 Clear Resin - 15000

Hardener - 17000

30 1:1 2300-2800

80 A high strength epoxy with 30-minutesworklife. Adhesion to wide variety of surfaces.

5101 Tan Resin - 80000

Hardener - 22000

20 1:1 2500-4500

80 Excellent adhesion to wide variety of

metals.

5110 UltraClear

Resin - 10500

Hardener - 5000

30 1:1 2700-4000

75 Excellent adhesion to glass to itself and wide variety of other surfaces. Impact resistance.

5125 Black

Resin - 6500

Hardener - 14000

60 1:1 1000-3000

85 A potting compound with good electrical properties. Black, low viscosity. Non-corrosive.

5130 Grey 100000 - 150000

HeatCure

1 Part 3000-7500

85 High strength, high temperatureresistant one part epoxy adhesive.Non-sag.

5135 White

35000 - 45000

HeatCure

1 Part 3000-4500

80 High temperature resistant, shelf leveling with excellent chemical resistant.

5140 OffWhit

e

Resin - 60000

Hardener - 8000

60 1:1 3500-4800

85 Rubber toughened, high strength with high peel and shear.

We also manufacture following adhesives:

• Cyanoacrylate Adhesives • Thread Locking Compounds • Gasketing Compounds • Retaining Compounds • UV Curable Adhesives • Polyurethane Adhesives • Silicone Adhesives and Sealant

PARBOND 150  High Performance Epoxy AdhesiveIndustrial Strength, 5-minutes Cure Speed    Features

Easy to use two component (part) system

54

Figure A7.12: Parabond Adhesive Selection

Excellent adhesion to wide variety of surfaces such as Balsa Wood, any hard and soft wood, Metals, Glass, Plastics, Rubbers and Ceramics

    Application Ideal adhesive for permanent, long lasting Model Airplane, Railroad, Boat, Car

assembly and repairs.

Ideal adhesive repair kit for quick household and industrial repairing.     Technical Specifications of PARBOND150

Description SpecificationMixing Ratio 1:1 vol/volWorking Life 7 to 15 minutesSet-up time 2-4 hoursTensile Strength 3700 psi

.PARBOND 300  Industrial Strength Epoxy AdhesiveHigh Performance, 30 minutes Cure Speed.    Features

Easy to use equal volume mix, two component (part) adhesive system

Excellent adhesion to wide variety of surfaces such as Wood, Any hard and soft wood, Metals, Ceramics, Concrete, Plastics, Rubbers, etc.

    Application Excellent adhesive for quick Model, Art, Craft, and Sculpture assembly and repair Aluminum filled adhesive build high strength bond with metal surfaces

Excellent adhesive system for quick household and industrial repairs     Technical Specifications of PARBOND 300

Description SpecificationMixing Ratio 1:1 vol/volWorking Life 25 to 30 minutesSet-up time 4-6 hoursTensile Strength 4700 psi

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 A-8: Prototype

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Figure A8.1: Fresh MIC-6 Aluminum Plates from Alcoa

Figure A8.2: Machining the Top Plate

57

Figure A8.3: Mechanical Prototype Awaiting Coupler Installation

Figure A8.4: Detail of Precision Ground Alignment Pin

58

Figure A8.5: Detail of Cable System (note reflection of dummy couplers on bottom plate)

Figure A8.6: Plates In Open Position (Left), and Bolted Together for RF Testing (Right)

59

Figure A8.7: Soldering the SMA Connectors to Coaxial Cable

Figure A8.8: Testing on the Network Analyzer

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Figure A8.9: Detail of Network Analyzer Display

Figure A8.10: Network Analyzer Connected to RF Couplers

A-9: Analyzer Results

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