BigBOSS Fiber Positioners Status 2012-07-18 Joe Silber 7/18/2012 - - PowerPoint PPT Presentation

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Oct 15, 2023 373 likes •513 views

BigBOSS Fiber Positioners Status 2012-07-18 Joe Silber 7/18/2012 LBNL 1 Infographic End cap (distributes optical fibers, control signals, power, cooling) Corrector (optics) Focal plate (5000 holes for 5000 positioners) Mayall 4m

SLIDE 1

BigBOSS Fiber Positioners Status

2012-07-18 Joe Silber

7/18/2012 1 LBNL

SLIDE 2

Infographic…

Mayall 4m Telescope Kitt Peak, Arizona Corrector (optics) End cap (distributes optical fibers, control signals, power, cooling) Focal plate (5000 holes for 5000 positioners) Fiber positioner, ø12mm (targets individual fibers

n individual galaxies)

7/18/2012 2 LBNL

SLIDE 3

USTC

currently building ø12.5 mm protos

7/18/2012 LBNL 3

SLIDE 4

IAA / AVS currently building ø12 mm protos

7/18/2012 LBNL 4

ø25mm SIDE, recently tested at LBNL excellent repeatability to 1μm ø12mm screenshot

SLIDE 5

Newscale Cobra LBNL is currently testing ø8 mm protos

7/18/2012 LBNL 5

SLIDE 6

LBNL currently testing ø12 mm R-θ protos

7/18/2012 LBNL 6

Everything is looking good. Repeatability: σ = 3μm (R-axis) σ = 4μm (θ-axis) See latest results in July SPIE paper (8450-116, or search my name, Joseph Silber)

SLIDE 7

LBNL R-θ proto repeatability plots from SPIE paper

7/18/2012 LBNL 7

1 2 3 4 5 6

5 10 R (mm) R - mean(R) @ target location (um) R- cord, proto#1, digital halls, 2012-06-22, precision R Backward (R < 0), =3, max-min=12 Forward (R > 0), =5, max-min=22

local directional means

50 100 150 200 250 300 350

0.1
0.08
0.06
0.04
0.02

0.02 0.04 0.06 0.08

 (deg)  - mean() @ target location (deg)

R- cord, proto#1, digital halls, 2012-06-20, precision  Forward ( > 0), =0.03, max-min=0.17 Backward ( < 0), =0.03, max-min=0.16

local directional means

SLIDE 8

Summary

USTC IAA / AVS Newscale LBNL Size (mm) ø12.5 ø12 ø8 ø12 Kinematics θ-φ θ-φ θ-φ R-θ Motors Stepper Stepper Piezo DC brushless with encoder Heritage LAMOST @ 1/4 scale SIDE @ 1/4 scale Cobra… @ 9/4 scale? Ghiorso, Silber, Schenk, Silber Current status USTC is building protos IAA is building protos LBNL is testing their protos LBNL is testing

ur protos

7/18/2012 LBNL 8

θ-φ … eccentric axis R-θ … polar

SLIDE 9

End

(Some more images of LBNL R-θ proto follow)

7/18/2012 LBNL 9

SLIDE 10

LBNL R-θ proto

7/18/2012 LBNL 10

240 mm φ11.7 φ10.0 FIBER FERRULE CLAMP POINT DRIVE ELECTRONICS θ STAGE BEARING CARTRIDGE R STAGE APPROX TO SCALE

SLIDE 11

LBNL R-θ proto

7/18/2012 LBNL 11

R STAGE (radial kinematics)

Batch of flexure leafs Upper housing + flexure Bearing + spool

Flexure acts as: 1) extensible linear bearing 2) anti-backlash spring 3) fiber radius control Multiple flexures are laminated in parallel on one tool.

Cord/spool tie-off HDPE gel-spun cord for actuation

SLIDE 12

LBNL R-θ proto

7/18/2012 LBNL 12

θ STAGE (angular kinematics)

θ stage transmits rotation around R drive components, then thru bearing to upper housing Preloaded bearing cartridge R-θ vs θ-φ kinematics θ rotational constraint (clamp) Bearing constraint

Bearing cartridge is the key datum, setting 5 DOF with respect to focal plane: X, Y, Z position XZ, YZ tilts Clamp fixes XY rot.

SLIDE 13

LBNL R-θ proto

7/18/2012 LBNL 13

MOTOR ASSEMBLY (drives R,θ)

Drive assembly inserts into R+θ unit Fiber + service bypasses via transfer gears Fiber runs along motors, then thru center Drive assy before fiber routing and insertion 2x 6mm DC brushless servos with 1024:1 gear heads Planetary transfer gears pre-bonded to make one unit FIBER CHANNEL FIXED PLANETS