Nested Rotation Mounts

Optic Carriage Rotates Within Mounting Ring
Models Available for Ø1" and Ø2" Optics
8-32 (M4) Tap for Post Mounting

LM1-B

Mounting Ring with Thumbscrew Retention

LM1-A

Optic Carriage

DLM1

Mounting Ring with
Magnetic Retention
(Includes Two DLM1-A
Carriages)

DLM1-A

Optic Carriage

DLM1-A

Optic Carriage

Related Items

Rotation Mounts

Quick-Release Optic Mount

Kinematic Feet

Magnetic Bases

Indexing Mount

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Overview
Threading Specs
Rotation Mounts and Stages
Feedback

Features

Optic Mounts with Interchangeable Rotating Optic Carriage
SM1- (1.035"-40) or SM2-Threaded (2.035"-40) Optic Carriage
Retaining Ring(s) Included for Secure Optic Mounting
Laser Engraved Scale with Graduations Every 2°, Labeled Every 20°
8-32 (M4) Tap for Post Mounting

These nested lens mounts systems consist of an inner optic carriage that rotates within the outer mounting ring. Single (LM1-B and LM2-B) and dual (DLM1) rotational optic versions are available. The optic carriages are radially laser engraved to allow for precise rotational changes. The optic carriages are retained within the mounting ring by either a thumbscrew or magnetic attachment. Additional optic carriages can be purchased and used for easy exchange of optics.

Click to Enlarge

Threading Specifications

The following is a general overview of screw threading. For more details regarding specifications and dimensions, please consult the Machinery's Handbook, available for purchase at many bookstores.

Features of a Thread
A thread consists of three repeating features: a crest, flank, and root (see drawing to the right). Except in special cases, threads have symmetrical sides inclined at equal angles when a vertical line is drawn through the center of a crest or root. The distance between corresponding points on adjacent threads is known as the pitch of the thread. The flank angle is defined as the angle the flank makes with a perpendicular ray drawn from the screw axis. Unless otherwise stated, threads have a flank angle of 30°, resulting in a total angle between flanks of 60°. Each feature is shown in the diagram to the right.

The major diameter is taken from the crests of a thread while the minor diameter is taken from the roots. For most screws, crests and roots do not terminate at a sharp point, so crest and root truncation values are included in the definitions of major and minor diameter. The pitch diameter is approximately halfway between the major and minor diameters.

Thread Form
A thread form is a set of rules that define the features' scale relative to one another. Common thread forms include the Unified Screw Thread Form, used in the United States of America and measured in imperial units, and the ISO Metric Screw Thread Form, used in many parts of the world and measured with the International System of Units. There are many thread forms in the Unified screw thread standard designated by either UN, which defines a flat root contour, or UNR, which defines a round root contour. These can be further described by appending more letters. For example, an extremely fine thread with a flat root contour is designated UNEF. Those forms which are not standardized by the Unified screw thread system are designated UNS.

Thread Series
Most screws are identified by their thread series. Thread series are denoted by the major diameter and density of threads. Unified threads specify density in threads per inch, while Metric threads specify the thread pitch. For example, in the Unified nomenclature, a 1/4"-20 cap screw has a 1/4" diameter barrel and the pitch is 20 threads per inch (TPI). In metric nomenclature, an M4 x 0.7 cap screw has a 4 mm barrel and the pitch is 1 thread per 0.7 mm. The term M4 x 0.7 is often shortened to just M4.

Unified Thread Class Tolerancing
Location	Loose	Optimal	Strict
Internal	1B	2B	3B
External	1A	2A	3A

Metric Thread Tolerance Positions
Location	Loose	Optimal	Strict
Internal	-	G	H
External	e or f	g	h

Metric Thread Tolerance Grades
Dimension	Location	Tolerance Grades^a
Minor Diameter	Internal	4, 5, 6, 7, 8
Major Diameter	External	4, 6, 8
Pitch Diameter	Internal	4, 5, 6, 7, 8
Pitch Diameter	External	3, 4, 5, 6, 7, 8, 9

The tolerance becomes looser as the grade increases. The underlined grades are used with normal lengths of thread engagement.

Thread Class
The tolerances and allowances on a thread series are given by a thread class. Unified thread classes are alphanumeric identifiers starting with a number from 1 through 3, where 1 is the loosest tolerance and 3 is the tightest, and either A for external threading or B for internal threading.

Metric threads have a slightly more complex tolerancing method that uses tolerancing grades, designated by a number 3 through 9; and tolerancing positions, which use letters e through h. Grades provide a measure of the tolerance itself: the smaller the number, the tighter the tolerance. Positions denote the distance of the tolerance from the pitch diameter. Uppercase positioning letters indicate internal threads while lowercase positioning letters indicate external threads.

Quoting from the Machinery's Handbook, 29th Edition, p. 1885: "To designate the tolerance class, the grade and position of the pitch diameter is shown first followed by that for the major diameter in the case of the external thread or that for the minor diameter in the case of the internal thread, thus 4g6g for an external thread and 5H6H for an internal thread. If the two grades and positions are identical, it is not necessary to repeat the symbols, thus 4g, alone, stands for 4g4g and 5H, alone, stands for 5H5H."

Thorlabs' SM Series Threads
Threading specifications for our SM threads, utilized in our lens tube and cage system components, are given below so that you can machine mating components to suit your application. Most SM series threads utilize a non-standard Unified thread form, indicated by the letters UNS, with a 30° flank angle and a thread class of 2A and 2B. The exception is our SM30 series thread, which is a Metric thread form with a 30° flank angle and a tolerance of 6H/6g. We also offer products with C-Mount and RMS threads, and the specifications for these threads are given below for reference. Please note that other manufacturers may have different tolerances for C-Mount and RMS threads. For other thread specifications that are not listed here, please contact Tech Support.

SM05 Threading: Ø1/2" Lens Tubes, 16 mm Cage Systems
External Thread, 0.535"-40.0 UNS-2A		Internal Thread, 0.535"-40.0 UNS-2B
Max Major Diameter	0.5340"	Min Major Diameter	0.5350"
Min Major Diameter	0.5289"	Min Pitch Diameter	0.5188"
Max Pitch Diameter	0.5178"	Max Pitch Diameter	0.5230"
Min Pitch Diameter	0.5146"	Min Minor Diameter (and 83.3% of Thread)	0.508"
Max Minor Diameter	0.5069"	Max Minor Diameter (and 64.9% of Thread)	0.514"

RMS Threading: Objective, Scan, and Tube Lenses
External Thread, 0.800"-36.0 UNS-2A		Internal Thread, 0.800"-36.0 UNS-2B
Max Major Diameter	0.7989"	Min Major Diameter	0.8000"
Min Major Diameter	0.7934"	Min Pitch Diameter	0.7820"
Max Pitch Diameter	0.7809"	Max Pitch Diameter	0.7866"
Min Pitch Diameter	0.7774"	Min Minor Diameter (and 83.3% of Thread)	0.770"
Max Minor Diameter	0.7688"	Max Minor Diameter (and 64.9% of Thread)	0.777"

C-Mount Threading: Machine Vision Lenses, CCD/CMOS Cameras
External Thread, 1.000"-32.0 UN-2A		Internal Thread, 1.000"-32.0 UN-2B
Max Major Diameter	0.9989"	Min Major Diameter	1.0000"
Min Major Diameter	0.9929"	Min Pitch Diameter	0.9797"
Max Pitch Diameter	0.9786"	Max Pitch Diameter	0.9846"
Min Pitch Diameter	0.9748"	Min Minor Diameter (and 83.3% of Thread)	0.966"
Max Minor Diameter	0.9651"	Max Minor Diameter (and 64.9% of Thread)	0.974"

SM1 Threading: Ø1" Lens Tubes, 30 mm Cage Systems
External Thread, 1.035"-40.0 UNS-2A		Internal Thread, 1.035"-40.0 UNS-2B
Max Major Diameter	1.0339"	Min Major Diameter	1.0350"
Min Major Diameter	1.0288"	Min Pitch Diameter	1.0188"
Max Pitch Diameter	1.0177"	Max Pitch Diameter	1.0234"
Min Pitch Diameter	1.0142"	Min Minor Diameter (and 83.3% of Thread)	1.008"
Max Minor Diameter	1.0068"	Max Minor Diameter (and 64.9% of Thread)	1.014"

SM30 Threading: Ø30 mm Lens Tubes
External Thread, M30.5 x 0.5 – 6H/6g		Internal Thread, M30.5 x 0.5 – 6H/6g
Max Major Diameter	30.480 mm	Min Major Diameter	30.500 mm
Min Major Diameter	30.371 mm	Min Pitch Diameter	30.175 mm
Max Pitch Diameter	30.155 mm	Max Pitch Diameter	30.302 mm
Min Pitch Diameter	30.059 mm	Min Minor Diameter (and 83.3% of Thread)	29.959 mm
Max Minor Diameter	29.938 mm	Max Minor Diameter (and 64.9% of Thread)	30.094 mm

SM1.5 Threading: Ø1.5" Lens Tubes
External Thread, 1.535"-40 UNS-2A		Internal Thread, 1.535"-40 UNS-2B
Max Major Diameter	1.5339"	Min Major Diameter	1.535"
Min Major Diameter	1.5288"	Min Pitch Diameter	1.5188"
Max Pitch Diameter	1.5177"	Max Pitch Diameter	1.5236"
Min Pitch Diameter	1.5140"	Min Minor Diameter (and 83.3% of Thread)	1.508"
Max Minor Diameter	1.5068"	Max Minor Diameter (and 64.9% of Thread)	1.514"

SM2 Threading: Ø2" Lens Tubes, 60 mm Cage Systems
External Thread, 2.035"-40.0 UNS-2A		Internal Thread, 2.035"-40.0 UNS-2B
Max Major Diameter	2.0338"	Min Major Diameter	2.0350"
Min Major Diameter	2.0287"	Min Pitch Diameter	2.0188"
Max Pitch Diameter	2.0176"	Max Pitch Diameter	2.0239"
Min Pitch Diameter	2.0137"	Min Minor Diameter (and 83.3% of Thread)	2.008"
Max Minor Diameter	2.0067"	Max Minor Diameter (and 64.9% of Thread)	2.014"

SM3 Threading: Ø3" Lens Tubes
External Thread, 3.035"-40.0 UNS-2A		Internal Thread, 3.035"-40.0 UNS-2B
Max Major Diameter	3.0337"	Min Major Diameter	3.0350"
Min Major Diameter	3.0286"	Min Pitch Diameter	3.0188"
Max Pitch Diameter	3.0175"	Max Pitch Diameter	3.0242"
Min Pitch Diameter	3.0133"	Min Minor Diameter (and 83.3% of Thread)	3.008"
Max Minor Diameter	3.0066"	Max Minor Diameter (and 64.9% of Thread)	3.014"

SM4 Threading: Ø4" Lens Tubes
External Thread, 4.035"-40 UNS-2A		Internal Thread, 4.035"-40.0 UNS-2B
Max Major Diameter	4.0337"	Min Major Diameter	4.0350"
Min Major Diameter	4.0286"	Min Pitch Diameter	4.0188"
Max Pitch Diameter	4.0175"	Max Pitch Diameter	4.0245"
Min Pitch Diameter	4.0131"	Min Minor Diameter (and 83.3% of Thread)	4.008"
Max Minor Diameter	4.0066"	Max Minor Diameter (and 64.9% of Thread)	4.014"

Rotation Mount and Stage Selection Guide

Thorlabs offers a wide variety of manual and motorized rotation mounts and stages. Rotation mounts are designed with an inner bore to mount a Ø1/2", Ø1", or Ø2" optic, while rotation stages are designed with mounting taps to attach a variety of components or systems. Motorized options are powered by a DC Servo motor, 2 phase stepper motor, piezo inertia motor, or an Elliptec™ resonant piezo motor. Each offers 360° of continuous rotation.

Manual Rotation Mounts

Rotation Mounts for Ø1/2" Optics
Item #	MRM05(/M)	RSP05(/M)	CRM05	PRM05(/M)^a	SRM05	KS05RS	CT104
Click Photo to Enlarge
Features	Mini Series	Standard	External SM1 (1.035"-40) Threads	Micrometer	16 mm Cage-Compatible	±4° Kinematic Tip/Tilt Adjustment Plus Rotation	Compatible with 30 mm Cage Translation Stages and 1/4" Translation Stages^b
Additional Details

This mount is available in the PRM05GL5 bundle, which includes the PRM05 rotation mount with the SM05PM5 polarizing prism mount.
The CT104 is complatible with the 1/4" translation stages using our MS103(/M) adapter plate.
The CT104 is compatible with the CT1A(/M) cage translation stage, which is designed for use with 30 mm cage systems.

Rotation Mounts for Ø1" Optics
Item #	RSP1(/M)	LRM1	RSP1D(/M)	DLM1(/M)	CLR1(/M)	RSP1X15(/M)	RSP1X225(/M)	PRM1(/M)^a
Click Photo to Enlarge
Features	Standard	External SM1 (1.035"-40) Threads	Adjustable Zero	Two Independently Rotating Carriages	Rotates Optic Within Fixed Lens Tube System	Continuous 360° Rotation or 15° Increments	Continuous 360° Rotation or 22.5° Increments	Micrometer
Additional Details

This mount is available in the PRM1GL10 bundle, which includes the PRM1 rotation mount with the SM1PM10 polarizing prism mount.

Rotation Mounts for Ø1" Optics
Item #	LM1-A & LM1-B(/M)	CRM1T(/M)	CRM1LT(/M)	CRM1PT(/M)	KS1RS	K6XS
Click Photo to Enlarge
Features	Optic Carriage Rotates Within Mounting Ring	30 mm Cage-Compatible^a	30 mm Cage-Compatible for Thick Optics^a	30 mm Cage-Compatible with Micrometer^a	±4° Kinematic Tip/Tilt Adjustment Plus Rotation	Six-Axis Kinematic Mount^a
Additional Details

This mount also features four 4-40 (M3) holes on the rotation dial for use with the K6A1(/M) prism platform.

Rotation Mounts for Ø2" Optics
Item #	RSP2(/M)	RSP2D(/M)	PRM2(/M)	LM2-A & LM2-B(/M)	LCRM2(/M)	KS2RS	K6X2
Click Photo to Enlarge
Features	Standard	Adjustable Zero	Micrometer	Optic Carriage Rotates Within Mounting Ring	60 mm Cage-Compatible	±4° Kinematic Tip/Tilt Adjustment Plus Rotation	Six-Axis Kinematic Mount
Additional Details

Manual Rotation Stages

Manual Rotation Stages
Item #	RP005(/M)	PR005(/M)	MSRP01(/M)	RP01(/M)	RP03(/M)	QRP02(/M)
Click Photo to Enlarge
Features	Standard					Two Hard Stops
Additional Details

Manual Rotation Stages
Item #	XRNR1(/M)	XRR1(/M)	PR01(/M)	CR1(/M)	XYR1(/M)	OCT-XYR1(/M)
Click Photo to Enlarge
Features	Fine Rotation Adjuster and 2" Wide Dovetail Quick Connect	Fine Rotation Adjuster and 3" Wide Dovetail Quick Connect	Fine Rotation Adjuster and SM1-Threaded Central Aperture	Fine Pitch Worm Gear	Rotation and 1/2" Linear XY Translation
Additional Details

The stage profile is higher when it is mounted using the screw slots rather than stacked on another stage or accessory with mating dovetails.
The OCT-XYR1(/M) stage includes the XYR1A solid sample plate. This plate can be detached from the stage to reveal the same mounting features present on the XYR1(/M) stage.

Motorized Rotation Mounts and Stages

Motorized Rotation Mounts and Stages with Central Clear Apertures
Item #	DDR25(/M)	PDR1(/M)	K10CR1(/M)	PRM1Z8(/M)^a	DDR100(/M)	ELL14	HDR50(/M)
Click Photo to Enlarge
Features	Compatible with SM05 Lens Tubes, 16 mm Cage System, 30 mm Cage System	Compatible with SM05 Lens Tubes, 30 mm Cage System, PD1(/M) and PDX1(/M) Linear Stages	Compatible with SM1 Lens Tubes & 30 mm Cage System		Compatible with SM1 Lens Tubes, 16 mm Cage System, 30 mm Cage System	Compatible with SM1 Lens Tubes, Open Frame Design for OEM Applications	Compatible with SM2 Lens Tubes
Additional Details

Motor Type	Brushless DC Servo	Piezo Inertia Drive	2 Phase Stepper Motor with Worm Gear	DC Servo	Brushless DC Servo	Piezo Resonant Motor	2 Phase Stepper Motor with Worm Gear
Rotation Adjustment Range	360° Continuous
Rotating Platform/Carriage
Diameter	Ø1.14" (Ø29.0 mm)	1.34" (34.0 mm)	Ø1.81" (Ø46.0 mm)	Ø1.97" (Ø50.0 mm)	Ø4.37" (111.0 mm)	-	Ø3.86" (Ø98.0 mm)
Height	1.12" (28.5 mm)	0.71" (18.0 mm)	0.84" (21.5 mm)	0.91" (23.0 mm)	1.57" (39.9 mm)	0.59" (15.1 mm)	1.73" (44.0 mm)
Threaded Mounting Holes	Four 4-40 with 16 mm Spacing	Four 8-32 (M4)	Six 4-40 (M3)	Four 6-32 (M4), Four 8-32 (M4), Four 4-40 with 30 mm Spacing	Eight 8-32 (M4), Four 1/4"-20 (M6), Four 4-40 with 16 mm Spacing, Four 4-40 with 30 mm Spacing	-	Four 8-32 (M4)
Center Aperture	SM05 Internal Threads, 1.2" (28.5 mm) Deep	Ø9.0 mm Clear Aperture with SM05 Internal Threads, 2.5 mm Deep	SM1 Internal Threads, 0.84" (21.5 mm) Deep	SM1 Internal Threads, 0.91" (23.0 mm) Deep	SM1 Internal Threads, 0.82" (21.0 mm) Deep	SM1 Internal Threads, 0.58" (14.7 mm) Deep	Ø50.0 mm Clear Aperture with SM1 Internal Threads, 6.9 mm Deep
Speed (Max)	1800°/s	20°/s	10°/s	25°/s	1080°/s	430°/s	50°/s
Platform Adapter Plate(s)	-	-	K10CR1A2(/M)	PRM1SP1(/M)	NR360SP9(/M) NR360SP4(/M)	-	NR360SP9(/M) NR360SP8 NR360SP4(/M)
Base
Dimensions	2.19" x 2.19" (55.6 mm x 55.6 mm)	1.57" x 1.57" (40.0 mm x 40.0 mm)	4.21" x 2.60" (107.0 mm x 66.0 mm)	5.18" x 3.26" (131.5 mm x 82.8 mm)	4.53" x 4.53" (115 mm x 115 mm)	2.60" x 3.25" (66.0 mm x 82.5 mm)	7.46" x 4.55" (189.4 mm x 115.5 mm)
Stage Adapter Plates	-	-	K10CR1A1 K10CR1A3	PRM1SP2 PRM1SP3	-	-	NR360SP2(/M) NR360SP5(/M)
Bottom Surface Mounting Holes	-	Two 8-32 (M4)	-	Two 1/4" (M6) Counterbores	Four 1/4" (M6) Clearance Holes	-	Four 1/4" (M6) Counterbores
Side Holes for Vertical Mounting	Four 8-32 (M4) Eight 4-40	One 8-32 (M4), Two Sides	Three 8-32 (M4)	Four 8-32 (M4)	Eight 1/4"-20 (M6)	-	Six 1/4"-20 (M6)
Cage System Compatibility	Four 4-40 Holes on Back Side with 16 mm Spacing, Four 4-40 Taps on Front Side with 30 mm Spacing	Ø6 mm Holes for ER Cage Rods with 30 mm Spacing	Four 4-40 Holes on Each Side with 30 mm Spacing	-	Four 4-40 Holes on Back Side with 30 mm Spacing	60 mm Cage using Four 0.12 (3.0 mm) Holes for 4-40 Screws, 30 mm Cage using SR025 Cage Rods to Adapt to ER Cage Rods	-

This stage is available in the KPRMTE(/M), which includes the PRMTZ8(/M) Motorized Rotation Stage with the KDC101 K-Cube DC Servo Motor Controller.

Motorized Rotation Mounts and Stages with Tapped Platforms
Item #	PRMTZ8(/M)^a	ELL18(/M)^b
Click Photo to Enlarge
Features	Tapped Mounting Platform for Mounting Prisms or Other Optics	Tapped Mounting Platform, Open Frame Design for OEM Applications
Additional Details

This stage is available in the KPRM1E(/M), which includes the PRMT1Z8(/M) Motorized Rotation Stage with the KDC101 K-Cube DC Servo Motor Controller.
This stage is available in the ELL18K(/M), which includes an interface board, mounting brackets, and connectors for PC control.

Posted Comments:
jjurado (posted 2011-09-02 14:06:00.0) Response from Javier at Thorlabs to wjlentz: Thank you very much for your feedback. We will look into offering a version for 3" diameter optics of our LM1 and LM2 mounts. I will contact you directly for further discussion. wjlentz (posted 2011-09-01 14:38:13.0) I need the 3" version of the rotating optical mount.

Nested Rotation Mount for Ø1" Optics

Zoom

Click to Enlarge
The optic carriage is locked in place by a thumbscrew and can be easily removed from the main body of the mount.

Mount Ø1" Optics up to 0.37" (9.4 mm) Thick
Optic Carriage (LM1-A) and Mounting Ring (LM1-B or LM1-B/M) Sold Separately
Rotating Optic Carriage is Interchangeable for Quick Swapping
SM1-Threaded Optic Bore in Rotating Optic Carriage
Post Mountable via 8-32 (M4) Tap
Laser Engraved Graduation Marks Every 2°, Labeled Every 20°

The LM1-A optic carriage can be nested inside of the LM1-B (LM1-B/M) mounting ring and offers 360° of continuous rotation for Ø1" optics. The optic bore of the LM1-A carriage features internal SM1 (1.035"-40) threading and can hold an optic up to 0.37" (9.4 mm) thick with the included SM1RR retaining ring or an optic in an SM1-threaded housing. The carriage attaches to the main body of the mount using a thumbscrew. To remove the carriage from the mount, simply loosen the thumbscrew. Extra LM1-A interchangeable rotating carriages are available to allow optics to be swapped out quickly and easily.

Each carriage has a 360° laser-engraved scale marked at 2° increments for precise, repeatable positioning. The top-located thumbscrew can be tightened to lock the rotation of the optic carriage and, along with the double bore on the mount, maintains a stable, three-point contact to hold the optic carriage. When the LM1-A is properly fastened in the LM1-B by the thumbscrew, the optic axis is 1.04" (26.3 mm for the LM1/B) above the top of the post.

Dual Nested Rotation Mount for Ø1" Optics

Dual Nested Rotation Mount for Ø1in Optics

Zoom

Click to Enlarge
The rotating optic carriages can be easily removed from the main body of the mount.

Mount Two Ø1" Optics up to 0.25" (6.4 mm) Thick
Two Optic Carriages (DLM1-A) Included with DLM1
Each Optic Carriage Rotates Independently
Rotating Optic Carriages are Interchangeable for Quick Swapping
SM1-Threaded Optic Bore in Each Rotating Optic Carriage
Two SM1RR Retaining Rings Included
Post Mountable via 8-32 (M4) Tap

The DLM1(/M) Dual Rotation Mount includes two independently rotating carriages (item # DLM1-A) for Ø1" optics that offer 360° of continuous rotation. The optic bore of the DLM1-A carriage features internal SM1 (1.035"-40) threading and can hold an optic up to 0.25" (6.4 mm) thick with the included SM1RR retaining ring or an optic in an SM1-threaded housing. The carriages magnetically attach to the main body of the mount. To remove a carriage from the mount, simply pull the carriage off the main body. Another carriage can then be snapped on in its place. Extra DLM1-A interchangeable rotating carriages are available to allow optics to be swapped out quickly and easily.

Each carriage has a knurled edge for adjusting rotation and a 360° laser-engraved scale marked at 2° increments for precise, repeatable positioning. Two top-located setscrews can be tightened with a 5/64" (2.0 mm) hex key or balldriver to lock the rotation of the optic carriages independently. When the rotation is locked, the double bore on the mount maintains a stable, three-point contact to hold the optic carriage.

The DLM1 mount is designed to put the optic axis 1.00" (25.0 mm for the DLM1/M) above the top of the post When two optics are mounted, the separation between them is 0.30" (7.6 mm). The dual rotation mount is ideal for creating variable polarizers and attenuators by mounting linear polarizers and wave plates in close proximity without having to align the optic axes of two separate rotation mounts. We do not recommend using this mount with lens tubes, as the torque applied to the optic bore may overcome the magnetic attachment.

Nested Rotation Mount for Ø2" Optics

Zoom

Mount Ø2" Optics Up to 0.46" (11.7 mm) Thick
Optic Carriage (LM2-A) and Mounting Ring (LM2-B or LM2-B/M) Sold Separately
Rotating Optic Carriage is Interchangeable for Quick Swapping
SM2-Threaded Optic Bore in Rotating Optic Carriage
Post Mountable via 8-32 (M4) Tap
Laser Engraved Scale with Graduations Every 2°, Labeled Every 20°

The LM2-A optic carriage can be nested inside of the LM2-B (LM2-B/M) mounting ring and offers 360° of continuous rotation for Ø2" optics. The optic bore of each carriage features internal SM2 (2.035"-40) threading and can hold an optic up to 0.46" (11.7 mm) thick with the included SM2RR retaining ring an optic in an SM2-threaded housing. The carriage attaches to the main body of the mount using a thumbscrew. To remove the carriage from the mount, simply loosen the thumbscrew. Extra LM2-A interchangeable rotating carriages are available to allow optics to be swapped out quickly at easily.

Each carriage has a 360° laser-engraved scale marked at 2° increments for precise, repeatable positioning. The top-located thumbscrew can be tightened to lock the rotation of the optic carriage and, along with the double bore on the mount, maintains a stable, three-point contact to hold the optic carriage. When the LM2-A is properly fastened in the LM2-B by the thumbscrew, the optic axis is 1.45" (36.8 mm for the LM2-B/M) above the top of the post.

Rotation Drive Mechanism and Adjustment Range	Manual, 360° Continuous			Coarse: Manual, 360° Continuous; Fine: Micrometer, ±7°	Manual, 360° Continuous
Optic Mounting	Internally SM05-Threaded Carriage
Maximum Accepted Optic Thickness	0.23" (5.8 mm)	0.23" (5.8 mm)	0.26" (6.5 mm)	0.23" (5.9 mm)	0.24" (6.0 mm)	0.41" (10.4 mm)	0.29" (7.3 mm)
Post Mounting	4-40 (M3) Stud	8-32 (M4) Tap	None	8-32 (M4) Tap	None	Two Counterbores for 8-32 (M4) Cap Screws	Two Counterbores for 4-40 (M3) Cap Screws
Cage System Compatibility	N/A				Four Bores for ∅4 mm Cage Rods with 16 mm Spacing	N/A	N/A^c

Rotation Drive Mechanism and Adjustment Range	Manual, 360° Continuous					Manual, Continuous: 360°; Discrete: 15°	Manual, Continuous: 360°; Discrete: 22.5°	Coarse: Manual, 360° Continuous; Fine: Micrometer, ±7°
Optic Mounting	Internally SM1-Threaded Carriage
Maximum Accepted Optic Thickness	0.47" (11.9 mm)	0.34" (8.6 mm)	0.51" (12.9 mm)	0.25" (6.4 mm)	0.27" (6.8 mm)	0.50" (12.7 mm)	0.50" (12.7 mm)	0.50" (12.7 mm)
Post Mounting	8-32 (M4) Tap	N/A	8-32 (M4) Tap
Cage System Compatibility	N/A							Four 4-40 (M3) Taps on Rotation Dial with 30 mm Spacing

Rotation Drive Mechanism and Adjustment Range	Manual, 360° Continuous			Coarse: Manual, 360° Continuous; Fine: Micrometer, ±7°	Manual, 360° Continuous
Optic Mounting	Internal SM1 Threads in LM1-A	Internally SM1-Threaded Carriage	Double-Bore with Setscrew	Internally SM1-Threaded Carriage
Accepted Optic Thickness	Max: 0.37" (9.4 mm)	Max: 0.37" (9.4 mm)	Min: 0.31" (7.9 mm)	Max: 0.37" (9.4 mm)	Max: 0.47" (11.9 mm)	Max: 0.55" (14 mm)
Post Mounting	8-32 (M4) Tap in LM1-B	8-32 (M4) Tap			Six Counterbores for 8-32 (M4) Cap Screws
Cage System Compatibility	N/A	Four Bores for ∅6 mm Cage Rods with 30 mm Spacing			N/A

Rotation Drive Mechanism and Adjustment Range	Manual, 360° Continuous		Coarse: Manual, 360° Continuous; Fine: ±7° Micrometer	Manual, 360° Continuous
Optic Mounting	Internally SM2-Threaded Carriage			Internal SM2 Threads in LM2-A	Internally SM2-Threaded Carriage
Maximum Accepted Optic Thickness	0.51" (13 mm)	0.54" (13.7 mm)	0.48" (12.2 mm)	0.46" (11.7 mm)	0.51" (13 mm)	0.47" (12 mm)	0.53" (13.4 mm)
Post Mounting	8-32 (M4) Tap			8-32 (M4) Tap in LM2-B	8-32 (M4) Tap	Four Counterbores for 8-32 (M4) Cap Screws	Six Counterbores for 8-32 (M4) Cap Screws
Cage System Compatibility	N/A		Four 4-40 (M3) Taps on Rotation Dial with 60 mm Spacing	N/A	Four Bores for Ø6 mm Cage Rods with 60 mm Spacing	N/A	N/A

Rotation Drive Mechanism and Adjustment Range	Manual, 360° Continuous
Mounting Platform
Diameter	Ø1.00" (Ø25.4 mm)	Ø1.00" (Ø25.4 mm)	Ø1.40" (Ø35.6 mm)	Ø2.07" (Ø52.8 mm)	Ø4.29" (Ø109.0 mm)	Ø2.00" (Ø50.8 mm)
Height	0.67" (17.0 mm)	0.75" (19.1 mm)	0.51" (13.1 mm)	0.63" (16.1 mm)	0.70" (17.8 mm)	1.00" (25.4 mm)
Taps	Six 4-40 (M3) One 1/4"-20 (M6)	One 8-32 (M4) Eight 4-40 (M3)	Four 4-40 (M3) One 8-32 (M4)	Four 8-32 (M4) One 1/4"-20 (M6)	Eight 6-32 (M4) Sixteen 8-32 (M4) Thirteen 1/4"-20 (M6)	Four 6-32 (M4) Four 8-32 (M4) Five 1/4"-20 (M6)
Additional Holes	Two Ø0.13" (Ø3.2 mm) Holes for FiberBench Accessories	-	Four Clearance Holes for 4-40 (M3) Cap Screws	-	-	-
Platform Adapter Plate(s)	-	-	-	-	-	-
Base
Dimensions	1.50" x 1.50" (38.1 x 38.1 mm)	1.50" x 1.50" (38.1 x 38.1 mm)	1.78" x 1.40" (45.2 x 35.6 mm)	2.45" x 2.45" (62.2 x 62.2 mm)	4.65" x 4.65" (118.1 x 118.1 mm)	2.55" x 2.55" (64.8 x 64.8 mm)
Mounting Holes	Four Clearance Holes for 1/4"-20 (M6) Cap Screws	Four Clearance Holes for 1/4"-20 (M6) Cap Screws	Four Clearance Holes for 4-40 (M3) Cap Screws	Four Clearance Holes for 1/4"-20 (M6) Cap Screws	Four Clearance Holes for 1/4"-20 (M6) Cap Screws	Four Counterbores for 1/4"-20 (M6) Cap Screws
Side Taps for Vertical Mounting	-	-	One 4-40 (M3)	One 8-32 (M4)	Three 8-32 (M4)	-
Cage System Compatibility	N/A

Rotation Drive Mechanism and Adjustment Range	Manual: 360° Continuous; Fine: Adjuster Screw, ±5°	Manual: 360° Continuous; Fine: Adjuster Screw, ±5°	Manual: 360° Continuous; Fine: Micrometer, ±5°	Worm Gear, 360° Continuous	Manual, 360° Continuous with 1/2" (13 mm) Linear Travel Along X and Y Axes with Micrometer
Mounting Platform
Diameter	Ø2.21" (Ø56.0 mm)	Ø3.19" (Ø81.0 mm)	Ø2.70" (Ø68.6 mm)	Ø1.70" (Ø43.2 mm)	Ø4.18" (Ø106.0 mm)	Ø4.04" (Ø102.5 mm)
Height	On Breadboard: 0.91" (23.0 mm)^a Dovetail Stacked: 0.83" (21.0 mm)	On Breadboard: 0.91" (23.0 mm)^a Dovetail Stacked: 0.83" (21.1 mm)	1.00" (25.3 mm)	1.00" (25.4 mm)	1.00" (25.4 mm)	1.65" (41.8 mm)
Taps	Thirteen 1/4"-20 (M6) Four 8-32 (M4) Four 6-32 (M4)	Thirteen 1/4"-20 (M6) Four 8-32 (M4) Four 6-32 (M4)	Four 4-40 (M3) Ten 6-32 (M4) Six 1/4"-20 (M6)	Four 4-40 (M3) Eight 6-32 (M4) Four 8-32 (M4)	Eight 4-40 (M3) Twelve 8-32 (M4) Sixteen 1/4"-20 (M6)	-^b
Additional Holes	-	-	Ø0.94" (Ø23.9 mm) Clear Aperture with SM1 Threading	-	Ø0.90" (Ø22.9 mm) Clear Aperture with SM1 Threading	-^b
Platform Adapter Plate(s)	-	-	PR01A(/M) CRA30(/M)	CR1A(/M)	XYR1A	-^b
Base
Dimensions	3.35" x 2.52" (85.0 mm x 63.9 mm)	4.33" x 3.58" (110.0 mm x 91.0 mm)	2.75" x 3.50" (69.9 x 88.9 mm)	2.76" x 2.10" (70.1 x 53.4 mm)	5.50" x 4.42" (139.7 x 112.3 mm) (Not Including Micrometers)
Mounting Holes	Four Mounting Slots for 1/4"-20 (M6) Cap Screws	Four Mounting Slots for 1/4"-20 (M6) Cap Screws	Four Mounting Slots for 1/4"-20 (M6) Cap Screws	Two Mounting Slots for 1/4"-20 (M6) Cap Screws	Four Mounting Slots for 1/4"-20 (M6) Cap Screws
Side Taps for Vertical Mounting	-	-	Two 1/4"-20 (M6)	-	-
Cage System Compatibility	-	N/A	Four 4-40 Taps on Top Surface for 30 mm Cage System	N/A	Four 4-40 Taps on Top Surface for 30 mm Cage System Four 4-40 Taps on Top Surface for 60 mm Cage System Four 4-40 Taps on Bottom Surface for 60 mm Cage System	-^b