P19310: LORD Vibration Isolator
/public/

Preliminary Detailed Design

Table of Contents

Team Vision for Preliminary Detailed Design Phase

Last phase’s goals that were proposed during the last phase review were all completed as following :

Top Level Design Concept

 Trade Show Setup

Trade Show Setup

 Mechanism

Mechanism

 Trade Show Full Setup

Trade Show Full Setup

 Electric Box Design

Electric Box Design

Feasibility: Prototyping, Analysis, Simulation

Baseplate Design

Stiffness analysis:

A stiffness analysis was performed to compare the stiffness of the new baseplate design compared to the previous baseplate. The team’s target when designing the new baseplate was to maintain equal or better stiffness in the new design. An arbitrary 50 lbf. load was applied in the z direction (perpendicular to the plane of the baseplate) on one side of the baseplate, while a fixed support was applied on the opposite side. It was found that the new baseplate design can be expected to be at least an order of magnitude more stiff (1000% increase) compared to the old baseplate in both the x and y directions. This means that the new design meets the target of having equal or better stiffness.

 Proposed baseplate

Proposed baseplate

A modal analysis was performed to ensure that the resonance modes of the new baseplate design were not near the operating frequencies of the vibrating system. The model determined that the first resonance frequency is about 315 Hz for the new design. This is sufficiently far from the expected 12 Hz operating frequency of the vibrating system. For future testing, the resonance modes of the entire vibrating system should be found, since the assembly could have different resonance from the individual parts.

Weight analysis:

A mass analysis was performed to ensure that the new baseplate would weigh less than the original baseplate, to fit with the team’s projected weight reduction target. Using the density of 6061 aluminum alloy, the model determined that two baseplates of the new design would weigh 2.7 lbm less than the old baseplate design.

System Cover/safety

Abstract:

Provide a clear enclosure to prevent injury to customer or LORD personnel while allowing clear view of device function.

Objective:

Ensures meeting of custom requirements: A02, A03, D03, ER07

Setup:

Slow-motion video testing shows a maximum deflection of 3mm. Cover plate will be made by an acrylic contractor used by P18310 and have a minimum of a 8mm gap between the vibrating mounting plate and the baseplate.

Results:

Cover is expected to function identically to P18310’s, as the only change is the sizing to fit the new design

Conclusion:

Shipping Pin design

 Shipping Pin

Shipping Pin

 Shipping Pin Mounted

Shipping Pin Mounted

New Electric Box

Abstract:

Determine if mass of new electronics system is below prior system to ensure weight saving goals are met

Objective:

Ensures meeting of custom requirements: R01, R02, R03, R04, O02, O03, A03

Setup:

Weigh both systems in prior and new configuration. New system is estimated to save 7 to 10 lbs over old system.

Results:

New system should meet minimum expected savings

Conclusion:

Wiring Scheme

 Wiring

Wiring

Draft Packaging Plan

Abstract:

Packaging layout for all components necessary for ensuring system will fit in allocated space in Pelican cases

Objective:

Ensures meeting of custom requirements: R01, R04, O03

Setup:

Model all parts in CAD and layout potential packaging plans. Check weights to ensure 45 lbs per case is not exceeded

Results:

Conclusion:

Flywheel Design

Abstract:

Optimize flywheel design to ensure connecting rods are mounted identical distances from the center of rotation.

Objective:

Assist in meeting ER06, accurate vibration measurement relies in part on systems being set-up identically between models and finished design.

Setup:

Design and machine new flywheel. New flywheel will have a single hole to mount the connecting rod to. This was a slot before hand, this made it extremely difficult to ensure connecting rods were in same locations. Additionally this allows reduction in size from the current flywheel.

 Flywheel

Flywheel

Hole placed at bottom of original slot, any higher causes isolators to max out

Conclusion:

MatLab Conversion

 System Operation Flowchart

System Operation Flowchart

 System Setup Flowchart

System Setup Flowchart

 GUI Design

GUI Design

In the GUI the variables created need to be assigned to their respected places in the GUI

Heat Test

Abstract:

A heat test was performed to ensure quality of performance with a smaller electric box design.

Objective:

The goal of this test is to determine the temperature of the electronics in a box without fans.

Setup:

Results:

 Temperature Vs Time

Temperature Vs Time

Conclusion:

The data was taken over a period of 20 minutes. From the data it is clear that the temperature did not reach equilibrium. Further testing will be required once smaller a electronics box is obtained until the data stabilizes.

Bill of Materials

 BOM Summary

BOM Summary

Review of Overall Design

 Mechanism

Mechanism

 Tradshown Full Setup

Tradshown Full Setup

Future Test Plans

Frequency Change/TVA Mass:

During prior testing (Phase 2), the team determined that the best vibration reduction percentage occured when the system was running at a target of 13 Hz. This is likely due to the fact that the TVA is best tuned for approximately 13 Hz. However, with the current system set-up, the 13 Hz vibration is too violent and causes the hardware to jump around on the table.

To handle this, the team is looking at re-tuning the TVA so that the optimal vibration reduction occurs at a lower frequency, or adjusting the mass of the vibrating system so that the higher frequency vibration does not cause the system to move around. As a parallel effort, the team is investigating ways to clamp down the system or otherwise prevent motion on the tabletop. Since the TVA will likely need to be re-tuned anyways, due to the shipping pin design, the team will be focusing on improving the vibration reduction at the lower frequency and reducing the vibrating mass concurrently. A model will be developed that will determine a target TVA mass given the new vibrating mass and isolator stiffness.

Vibrating System Mass:

Related to the optimization of the vibration reduction percentage at the target operating frequency, the team will investigate the potential for mass reduction in the vibrating system. Similar to the new baseplate design, excess material can be removed some several parts, including the mounting plate (plate which motor, piston, accelerometer, etc. are mounted to), the piston supports, and the TVA mounting plate. Analysis will be conducted to ensure that the structural properties of the parts are not compromised by removing too much material.

Risk Assessment

 Snapshot of Risk Assessment

Snapshot of Risk Assessment

Lessons Learned

Team Vision For Next Phase


Home | Planning & Execution | Imagine RIT

Problem Definition | Systems Design | Preliminary Detailed Design | Detailed Design

Build & Test Prep | Subsystem Build & Test | Integrated System Build & Test | Customer Handoff & Final Project Documentation