P08028: Magnet Centering Device
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Test Procedures and Results

Table of Contents

To insure that components of the device met the customer expectation a number of test were performed on these components. In validating and verifing these components the results from these tests were compared to the customer needs and a pass/fail criteria for each individual component was noted.

Leveling of Device Test Results

To insure that tolerance did not affect the centering process, each component of the assembled test rig was leveled off using the Coordinate Measuring Machine (CMM)

Rotary Stage Test Results

The wobble of the rotary stage used in the mapping of magnetic fields and measuring of the bushings center was tested. The wobble would affect the results of the readings therefore producing false results corrupting the centering process.

Load Cell Test Results

This test was performed on the load cell from Transducer Technique, model DSM 50. The test was to verify and calibrate the load cell for device. However, when weight was applied to the load cell, the change in voltage was low, too low for the data acquistion card to pick up. Therefore an operation ampliflier was added to increase the voltage output and then the test was performed.

Lower and Upper Vacuum Chuck Test Results

The test for the lower and upper vacuum chucks were performed to verify that the holding force of the components is acceptable to hold the magnet and bushing. Weight was added to each component, at different psi, and when the vacuum failed to hold the weight that value was recorded.

Spreadsheet from tests

XY Linear Stages Test Results

For the test involved in measuring the accuracy and repeatability of the Thorlabs linear stage, the laser sensor from Acuity was used. Because the of precision in the measuring ability of the laser was small, the factory calibrations were used as verification for the laser. Therefore the linear stages were moved in one micron steps and the numbers from the linear stages and laser were compared.

Upper Vacuum Chuck Test Results

The upper vacuum chuck was tested to center it to the axis of rotation of the rotary stage. The precision of the centering the upper vacuum chuck is not crucial, however having the upper vacuum chuck near the axis of rotation will decrease the time to center the magnetic field. There is no pass/fail criteria for this test, the test was done to insure that the upper vacuum chuck is near the axis of rotation.

Adhesive Test Results

Once the bushing and magnetic field have been centered, the bushing and magnet need to be attached to one another. To accomplish this a number of adhesives were test and compared to identify the best adhesive.

Analysis of Shear Force required to move bushing or magnet

Bushing Centering Test Results

Test were performed using the Acuity laser, XY linear stages and the lower vacuum chuck. The bushing was placed on the lower vacuum chuck and the peak values were determined and the difference between them were taken. This was done until the bushings center was less than a micron.

Magnetic Field Centering Test Results

Test were performed using the each component of the assembly. The bushing was placed on the lower vacuum chuck and the magnet was placed on the upper vacuum chuck. The magnetic field and bushings centers were determined. Once the centers were found the bushing and magnet were attached to one another. The results of this test need to be within 25 microns per customer needs.

Centered Results

Complete Tabulation of Test Results

 Chart illustrates the engineering spec. to the tested results

Chart illustrates the engineering spec. to the tested results