P17618: Lens Handling Fixture
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Preliminary Detailed Design

Table of Contents

Additional Notes for Preliminary Detailed Design Phase

Due to the fact that the overall goal for this project changed during the coarse of this phase, our EDGE page will look different than previous years. Some sections are to be determined, and documents will be uploaded when the work is completed.

Team Vision for Preliminary Detailed Design Phase

Going into the Preliminary Detailed Design Phase, the goal was to develop a prototype and perform analyses to verify the design’s stress mitigation on the lens. Feedback from the System Design Review led us to pursue a Push-Pull solution. We decided on two priority objectives:

  1. Determine an effective way to “pull” the lens from the top
  2. Determine a method to interface/adhere the pulling method onto the lens so that the pulling forces would transition into the lens.

In order to successfully work through this phase, our team researched current industry solutions, and brainstormed push/pull solutions and “adhesion” methods. A follow up meeting was scheduled to obtain feedback on two paths that we considered for implementing the pulling forces into the lens:

  1. adhesives
  2. vacuum pump seal

During this meeting we were advised that it would be best to focus on a high aspect ratio (very thin) lens solution, which would be problematic for either option due to small circumferential surface area. The change was due to upcoming work orders for high aspect ratio lenses and because of a recently developed solution for larger lenses with moderate to low aspect ratios (that we were previously focusing on). However, the current solution was highly expensive to produce and will most likely remain one of a kind. Overall, the new scope focuses on creating a fixture and characterizing the known stress inflicted by the fixture to be able to back out the actual deformation present in a lens. The specific lenses in question have 10”-14” diameters and high aspect ratios (exact range to be determined). It is desired that the solution be simplistic in nature, cost effective, relatively easy to manufacture, and more universal.

Before Goal Change

Decisions After Design Review

After coming out of the Systems Design Review, our team decided to pursue a horizontal Push-Pull mount inspired by the ASML Lithography Corporation in Wilton Conneticut. More details are outline in the "Opto-Mechanical Systems Design: Design and Analysis of Large Mirrors and Structures", 4th edition, Volume 2.

 Decisions to pursue after Design Review

Decisions to pursue after Design Review

Roder, Paul and Vukobratovich, Daniel. Opto-Mechanical Systems Design: Design and Analysis of Large Mirrors and Structures, Fourth Edition, Vol. 2. 4th ed. CRC Press, 2015, pp. 136.

Research

To continue improving our design, and to not forget the fact that the original customer requirements required the mount to be for horizontal and vertical oriented mirrors, more research regarding vertical oriented mounts was included.

However, it was also confirmed coming out of the system design review that we should focus more on horizontal configuration mounts. We needed to focus on horizontally oriented mounts because there is a "backlogging" effect i.e. a lack of horizontal mounts which slowed production.

Research Mounts

 Mathematical Models to describe Gravity Self Deflection of Vertically Oriented Mirrors

Mathematical Models to describe Gravity Self Deflection of Vertically Oriented Mirrors

Roder, Paul and Vukobratovich, Daniel. Opto-Mechanical Systems Design: Design and Analysis of Large Mirrors and Structures, Fourth Edition, Vol. 2. 4th ed. CRC Press, 2015, pp. 142.

 Common Ring Mounts

Common Ring Mounts

Roder, Paul and Vukobratovich, Daniel. Opto-Mechanical Systems Design: Design and Analysis of Large Mirrors and Structures, Fourth Edition, Vol. 2. 4th ed. CRC Press, 2015, pp. 143.

 Other Inspired Mounts

Other Inspired Mounts

Roder, Paul and Vukobratovich, Daniel. Opto-Mechanical Systems Design: Design and Analysis of Large Mirrors and Structures, Fourth Edition, Vol. 2. 4th ed. CRC Press, 2015, ch. 4.

Subject Matter Expert Meetings

In order to gain more inspiration for our design, the team set up a meeting with Jack Kelly, a researcher at the University of Rochester's Laser Lab. He was referred to us by Robert Kremens, a research professor at the RIT College of Imaging Arts and Sciences.

Subject Matter Expert Meetings
Date Contact Credentials Summary of Meeting
02/27/2017 Robert Kremens Research Professor at Center for Imaging Science
  • Mentioned AeroTech Mounts
  • Material Suggestion: stress relieved aluminum for temperature distortion resistance
  • Referred to Jack Kelly
03/08/2017 Jack Kelly University of Rochester Laboratory for Laser Energetics
  • Suggested Klinger mounts
  • Lens holders use a two part system:
    • Lens adhered to mount
    • Back layer of pneumatic actuators to move the mount
  • All lens mounts are V type with Teflon securing lens in mount

Jack Kelly was kind enough to show us some of their modified AeroTech Mounts. Pictures are supplied and include some of the key factors we took into consideration in our brainstorming phase.

 University of Rochester Mounts

University of Rochester Mounts

Jack Kelly also showed us around to one of the largest laser configurations built in the lab. He highlighted how their large mirrors were held together with adhesive. No pictures are provided, however we also took that into consideration in our brainstorming phase.

Adhesives Research

In order to see if adhesives could be applied to connect the "push-pull" mount to the lens, more research was conducted with regards to general marketplace adhesives.
Adhesives Research
Double Sided Tape Spray Adhesives
Pros Cons Pros Cons
  • Easy to apply
  • No potential for over spray or extra contamination
  • Environmentally neutral
  • Relatively strong
  • Fast adhesion time
  • Bonds wide variety of material
  • “Permanent” tape can cause surface damage
  • Potentially difficult to remove
  • Takes more time to actually apply than spray
  • More tape must be used to achieve higher strength adhesion
  • Quick to apply
  • Easier to remove
  • “Industrial” strength spray is available
  • Relatively strong
  • Can use more spray over smaller area to achieve higher adhesion strength vs tape
  • Unlikely to leave surface damage
  • Aerosol pollutants
  • Potentially harmful
  • Highly flammable
  • Potential for over spray/contamination
  • Potentially longer dry time

Brainstorming & New Concept Generation

After we compiled all of the data and outside inspiration, our team tried to focus on solving two key problems:

  1. How are we going to push/pull the lens?
  2. How are we going to attach the push/pulling mechanism to the lens?

We generated the following concepts from our 2nd brainstorming iteration, continuing the pattern from the Systems Design Review.

 Other Concept Generation Cycle 3

Other Concept Generation Cycle 3

Feasibility: Prototyping, Engineering Analysis, Simulation

Large Circular Ring

The team realized that a lot of our brainstorming designs involved some sort of "ring" which encompassed the lens. In order to test the feasibility of a majority of our designs, we decided to ask the machine shop to create a large circular ring from various scrap metal.

 Prototype Ring

Prototype Ring

We learned two things from the prototype:

  1. It is hard to manufacture perfect circles with the correct radius.
  2. The base provided helped us to explore more "attachment" options which could be added to the "base circular design" in order to provide a more detailed design.

Ferromagnetic Material

Another idea the team explored was the possibility of pursuing a ferromagnetic material which would help push/pull the lens for the correct stress profile.

 Ferromagnetic Testing

Ferromagnetic Testing

However, the experiment could not be performed because we did not have access to the correct materials.

It was later learned after the preliminary design review that Company X uses ferromagnetic material as a waste product in their production lines. However, pursuing a sustainable/reusable solution is not within the time constraints of the project. Company X suggested that this could be a "Version 2" that can be added to the base design in future generations.

FEA Simulation

After the Systems Design Review, it was made clear that the FEA simulations for our concept design is critical deliverable. As a result, our team decided to start learning the FEA Solidworks package early on. Below are some examples of assembly simulations we tried to run for one of our brainstorming concepts.

 Preliminary FEA Analysis

Preliminary FEA Analysis

We later sat down with one of the employees from Company X and learned the specific process uses in order to create FEA solidworks simulations. See Detailed Design Private for more information.

Turning Point

Throughout our entire process, our team kept hitting a wall with trying to solve one of our sub-problems. Our team went back to the functional decomposition and, again, we were trying to solve one distinct sub-problems:

  1. How are we going to attach the push/pulling mechanism to the lens?
 Functional Decomposition Version 2

Functional Decomposition Version 2

We came up with two solutions to the problem:

And we didn't know which solution was better. So, we decided to consult Company X to see which path we should go down.

Our biggest concern was: how were going to attach our "push/pull" mechanism without breaking the lens?

During the meeting, we learned that neither solution would work due to a change in the company's needs. A new solution was made in the previous weeks which fulfilled all of our previous customer requirements.

Company X asked us if we could change our scope and focus on creating a new horizontal solution for high aspect ratio parts. We said, "Sure! We still have like 6 weeks and we don't want our project to turn into a paper weight. Let's build something that you can use!"

In response to this, we asked them to review the following customer requirements and re-rate them in terms of importance.

 Functional re-rating the customer requirements

Functional re-rating the customer requirements

After Goal Change

New Goal: Create a “new solution” that can give a “good enough” stress profile but is more manufacturable that focuses on high aspect ratios!

 Restating Customer Requirements

Restating Customer Requirements

Technician Interviews

After we learned of the goal change, the first thing the team did was return to company X to gain inspiration on their solutions for high aspect ratio lenses.

The information is classified and can be found in the picture below.

 Company X High Aspect Ratio Solutions

Company X High Aspect Ratio Solutions

Concept Generation

At the same time as we were getting into gear conducting technician's input, we also generated some simple concepts which we hoped to lead us down the right path in this trying to solve this new problem. This information is proprietary and cannot be access by outside personnel.
 Ideas Version 1

Ideas Version 1

Feedback Concept Generation

 Feedback for Ideas

Feedback for Ideas

The general feedback from the designs was the following:

We never anticipated the "settling" or "vibration" problem, so our team and Company X decided it was best to pursue a solid mechanical interface solution.

The full technician interviews document can be found here: //private/FullTechnicianReview.xlsx.

Final Design Selection

After consulting with Company X after the Preliminary Design Review, the team was down to two options:

  1. Using a sort of immersion fluid tank to suspend the lens in a horizontal configuration.
  2. Using a previously created solution but on a larger scale.

Due to time constraints and company preference, the team decided to pursue a larger scale of a previously created solution with the following abilities: adapting it to larger size lenses in the "feet" and adding a tilt adjustment on the "top slider".

A picture of the general final design is classified and can be found in the link below. The idea is based on a Company X and is proprietary.

 Final Design

Final Design

We also learned that the requirements for the transmission test was unnecessary due to time constraints and the changed scope in the project.

 Updated Customer Requirements

Updated Customer Requirements

Risk Assessment

Here is a version of our updated Risk Assessment.

Plans for next phase

Detailed Design Presentation

Presentation


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