PXL Mechanical

• Hinge rework in aluminum and carriage redesign

• Kinematic rework and analysis• Insertion test - detailing and fabrication

instructions• Spatial Calibration

New carriage design

Low mass, reduced space usage

Test of cable load support

Analysis in seconds

Hinge structure in aluminum, improved stability. Low mass, 2 mm thick - stable. Expanded air duct passage.

Cam guide FEE check20 lb load, 20 micron deflection, yield – no problem

Kinematic mounts, cock and lock spring loaded contacts to define detector location when inserted

Kinematic Mounts

Insertion and Retraction Forces

May 11, 2010

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Joseph Silber

Behavior to model

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Offset, Radii

• Horizontal offset makes manual analysis of design difficult.

• R1 ≠ R2 contributes further to this.

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Further considerations• Constraint surfaces are not C1 continuous, so contact

conditions require some additional searching logic, and discontinuities in calculated forces are expected.

• The combined assembly consists of two “top” mounts and one “bottom”. These effects must be calculated in phase with each other for summing up the forces.

• Total insertion and retraction force differ in magnitude, due to non-conservative friction forces.

• Friction forces differ depending on static versus dynamic.

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Status

• We now have a general code for analyzing kinematic constraints of arbitrary piecewise complexity.

• Now use code to optimize the design.

• Analysis of current design shows potential gains in:– smoothing the insertion and retraction force curves– eliminating the negative force condition (“suck-in”)– simplifying the offset and radius conditions of contacts

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rail test system

rail_test_system.SLDASM

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5/3/2010this document: http://www-rnc.lbl.gov/~wieman/Rail_test_system.pptxmodels: http://www-rnc.lbl.gov/~wieman/rail_test_system_05_03_10.zip

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part/file cnfg material source total#

p. ref

grf

1 PIT_glue_plate_to_rail_hanger_free.SLDPRT 6061 UTA 16

2 PIT_end_fixture.SLDPRT PIT east end MIC6 LBNL/UTA? 1

3 PIT_end_fixture.SLDPRT PIT west end MIC6 LBNL/UTA? 1

4 PIT_end_fixture.SLDPRT PST east end MIC6 LBNL/UTA? 1 later

5 PIT_end_fixture.SLDPRT PST west end

MIC6 LBNL/UTA? 1 later

6 Tooling ball MC 8481A34 steel MC 36

7 tee_nut_custom_half_in_slot.SLDPRT 6061 UTA 6

8 PIT_base_fixture.SLDPRT PIT MIC6 LBNL/UTA? 1

9 PIT_base_fixture.SLDPRT PST MIC6 LBNL/UTA? 1 later

10 PIT_fixture_flex_lever.SLDPRT 6061 UTA 4

11 PIT_hole_fixture_end_addapter.SLDPRT 6061 UTA 1 later

12 PIT_hole_fixture_end_addapter_mirrored.SLDPRT 6061 UTA 1 later

13 dowel pin 0.125 X .375 in, MC 98381A470 steel MC 4 later

14 PIT_hole_fixture_beam.SLDPRT 6061 UTA 1 later

parts list for assembly: rail_test_system.SLDASM

example

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this plane perpendicularto a ref cylinder axis

line betweenholes centered onref cylinder axis to ±0.05 mm

separation tolerance±0.05 mm or match drilledwith butch_plate_single.SLDPRT

diameter tolerance:+0.000 mm-0.005 mmfor bullet insert press fit

this and other 2 similar planestolerances to chord and axisof ref cylinder: ±0.05 mm

±0.05 mm tolerances are to preserve glue bond thicknesses

these and other similar holesdiameter tolerance:±0.005 mmfor press fit with tooling balls,glue in OK if ends up sloppy

grand_master.SLDPRT

Example tolerance spec

development of spatial mapBob ConnorsSpiros MargetisYifei Zhang

touch probe 2-3 m (xyz) andvisual 2-3 m (xy) 50 m (z)

active volume: huge

10 gm touchprobe force

visual sub micron (xyz) repeatability 5 m accuracy over active volume

no touch probe

active volume: 30 in X 30 in X 12 in

MEMOSTAR3, 30 m pitch

Visualization of touch probe data in solid works

Coordinate Measuring Machine gives touch probe ball location plus a unit vector in the direction of the touch force. This figure shows ball location plus ball radius times unit vector.

Michal and Xiangming have developed code for putting coordinate machine data into more convenient form