Products Home / Optomechanical Components / Optical Cage Systems / 30 mm Cage Components / 30 mm Cage System Optic Mounts / Rotation Mounts / 30 mm Cage System Rotation Mounts for Ø1" or Ø25.0 mm Optics30 mm Cage System Rotation Mounts for Ø1" or Ø25.0 mm Optics
- Manual or Micrometer Driven Rotation
- SM1 Threaded or Double Bored with Setscrews
- Lockable, 360° of Continuous Rotation
2° Dial Graduations
Labeled Every 20°
SM1 Threaded
CRM1
CRM1L
Double Bored
with Setscrew
±7° of
Precision
Micrometer
Adjustment
CRM1P
Application Idea
Please Wait
| Alternative Size Options |
|---|
| 16 mm Cage Rotation Mounts |
| 30 mm Cage Rotation Mounts |
| 60 mm Cage Rotation Mounts |
Features
- Accepts Ø1" or Ø25.0 mm Optics
- 360° Coarse Rotation, Lockable
- Precise Positioning of Wave Plates, Polarizers, and Other Polarization Optics
- 2° Graduations on Dial, Labeled Every 20°
- Compatible with Thorlabs 30 mm Cage System
- Post Mountable
Our 30 mm cage system rotation mounts provide 360° of continuous rotation with a locking screw to fix the position of the mount once the optic has been aligned. The smooth adjustment mechanism allows for precise positioning of a variety of optics. All of the CRM1 series rotation mounts are compatible with Thorlabs' 30 mm cage system and the CRM1(/M), CRM1P(/M), and CRM1L(/M) rotation mounts can also be mounted on a TR series post.
These rotation mounts are designed to accept Ø1" (Ø25.4 mm) optics. They are also mechanically compatible with Ø25.0 mm optics, but we only recommend this for applications in which the centration of the optics is not critical. The CRM1(/M) and CRM1P(/M) have an SM1 (1.035"-40) internally threaded central hole, which are then retained with an SM1RR retaining ring. Alternatively, the CRM1L(/M) has an double-bored central hole where the optic is retained using a setscrew.
Thorlabs also offers prism mounts that are compatible with the CRM1 rotation mounts. The K6A1(/M) is a compact platform that comes with a clamping arm and mounting screws, thus allowing the user to easily mount prisms to the rotation mount. The SM1PM10 and SM1PM15 are designed to mount our polarizing prisms and feature an external SM1 threading (see below for more details). For our complete selection of rotation mounts and stages, please see the Rotation Mounts and Stages tab.
Cage System Overview
The Cage Assembly System provides a convenient way to construct large optomechanical systems with an established line of precision-machined building blocks designed for high flexibility and accurate alignment.
16 mm, 30 mm, and 60 mm Cage System Standards
Thorlabs offers three standards defined by the center-to-center spacing of the cage assembly rods (see image below). The 16 mm cage, 30 mm cage, and 60 mm cage standards are designed to accomodate Ø1/2", Ø1", and Ø2" optics, respectively. Specialized cage plates that allow smaller optics to be directly inserted into our larger cage systems are also available.
Standard Threads
The flexibility of our Cage Assembly System stems from well-defined mounting and thread standards designed to directly interface with a wide range of specialized products. The three most prevalent thread standards are our SM05 Series (0.535"-40 thread), SM1 Series (1.035"-40 thread), and SM2 Series (2.035"-40 thread), all of which were defined to house the industry's most common optic sizes. Essential building blocks, such as our popular lens tubes, directly interface to these standards.
An example of the standard cage plate measurements determining cage system compatibility.
| Standard Cage System Measurements | |||
|---|---|---|---|
| Cage System | 16 mm | 30 mm | 60 mm |
| Thread Series | SM05 | SM1 | SM2 |
| Rod to Rod Spacing | 16 mm (0.63") | 30 mm (1.18") | 60 mm (2.36") |
| Total Length | 25 mm (0.98") | 41 mm (1.60") | 71.1 mm (2.8") |
| Cage Components | ||
|---|---|---|
| Cage Rods | 16 mm | These rods are used to connect cage plates, optic mounts, and other components in the cage system. The SR Series Cage Rods are compatible with our 16 mm cage systems, while the 30 mm and 60 mm cage systems use ER Series Cage Rods. |
| 30 mm | ||
| 60 mm | ||
| Cage Plates | 16 mm | These serve as the basic building blocks for a cage system. They may have SM-threaded central bores, smooth bores sized for industry standard optics or to accommodate the outer profile of our SM Series Lens Tubes, or specialized bores for other components such as our FiberPorts. |
| 30 mm | ||
| 60 mm | ||
| Optic Mounts | 16 mm | Thorlabs offers fixed, kinematic, rotation, and translation mounts specifically designed for our Cage Systems. |
| 30 mm | ||
| 60 mm | ||
| Cage Cubes | 16 mm | These cubes are useful for housing larger optical components, such as prisms or mirrors, or optics that need to sit at an angle to the beam path, such as beamsplitters. Our cage cubes are available empty or with pre-mounted optics. |
| 30 mm | ||
| 60 mm | ||
| Post and Breadboard Mounts and Adapters | Mounting options for cage systems can be found on our Cage System Construction pages. Cage Systems can be mounted either parallel or perpendicular to the table surface. | |
| Size Adapters | Cage System Size Adapters can be used to integrate components from different cage system and threading standards. | |
| Specialized Components | Thorlabs also produces specialized cage components, such as Filter Wheels, a HeNe Laser Mount, and a FiberPort Cage Plate Adapter, allowing a wide range of our products to be integrated into cage-mounted optical systems. Explore our Cage Systems Visual Navigation Guide to see the full range of Thorlabs' cage components. | |
Click to Enlarge
Figure 1: An example of how to read a vernier scale. The red arrow indicates what is known as the pointer. Since the tick mark labeled 10 on the vernier scale aligns with one of the tick marks on the main scale, this vernier scale is reading 75.60 (in whatever units the tool measures).
Reading a Vernier Scale
Vernier scales are typically used to add precision to standard, evenly divided scales (such as the scale on Thorlabs' rotation mounts). A vernier scale has found common use in many precision measurement tools, the most common being calipers and micrometers. The direct vernier scale uses two scales side-by-side: the main scale and the vernier scale. The vernier scale has a slightly smaller spacing between its tick marks (10% smaller than the main). Hence, the lines on the main scale will not line up with all the lines on the vernier scale. Only one line from the vernier scale will match well with one line of the main scale, and that is the trick to reading a vernier scale.
Figures 1 through 3 show a vernier scale system for three different situations. In each case, the scale on the left is the main scale, while the small scale on the right is the vernier scale. When reading a vernier scale, the main scale is used for the gross number, and the vernier scale gives the precision value. In this manner, a standard ruler or micrometer can become a precision tool.
The 0 on the vernier scale is the "pointer" (marked by a red arrow in Figs. 1 - 3) and will indicate the main scale reading. In Figure 1 we see the pointer is lined up directly with the 75.6 line. Notice that the only other vernier scale tick mark that lines up well with the main scale is 10. Since the vernier 0 lines up with the main scale’s 75.6, the reading from Figure 1 is 75.60 (in whatever units the tool measures in).
That is essentially all there is to reading a vernier scale. It's a very straightforward way of increasing the precision of a measurement tool. To expound, let’s look at Figure 2. Here we see that the pointer is no longer aligned with a scale line, instead it is slightly above 75.6, but below 75.7; thus the gross measurement is 75.6. The first vernier line that coincides with a main scale line is the 5, shown with a blue arrow. The vernier scale gives the final digit of precision; since the 5 is aligned to the main scale, the precision measurement for Figure 2 is 75.65.
Since the vernier scale is 10% smaller than the main scale, moving 1/10 of the main scale will align the next vernier marking. This asks the obvious question: what if the measurement is within the 1/10 precision of the vernier scale? Figure 3 shows just this. Again, the pointer line is in between 75.6 and 75.7, yielding the gross measurement of 75.6. If we look closely, we see that the vernier 7 (marked with a blue arrow) is very closely aligned to the main scale, giving a precision measurement of 75.67. However, the vernier 7 is very slightly above the main scale mark, and we can see that the vernier 8 (directly above 7) is slightly below its corresponding main scale mark. Hence, the scale on Figure 3 could be read as 75.673 ± 0.002. A reading error of about 0.002 would be appropriate for this tool.
As we've seen here, vernier scales add precision to a standard scale measurement. While it takes a bit of getting used to, with a little practice, reading these scales is fairly straightforward. All vernier scales, direct or retrograde, are read in the same fashion.
Click to Enlarge
Figure 2: An Example of a vernier scale. The red arrow indicates the pointer and the blue arrow indicates the vernier line that matches the main scale. This scale reads 75.65.
Click to Enlarge
Figure 3: An Example of a vernier scale. The red arrow indicates the pointer and the blue arrow indicates the vernier line that matches the main scale. This scale reads 75.67, but can be accurately read as 75.673 ± 0.002.
| Posted Comments: | |
Eneko Lopez
(posted 2020-11-18 11:25:42.51) Hello, I am interested in mounting GTH10M-B polarizer into a cage system. Are these (CRM1/M or CRM1P/M) compatible? thank you YLohia
(posted 2020-11-20 10:40:09.0) Hello, yes, both mounts can hold the GTH10M-B. However, you will need to put the polarizer into the SM1L20 lens tube first in order to thread into the SM1 holes on these mounts. karol.686
(posted 2018-07-16 09:06:38.153) I'm interested in CRM1P/M, but I wonder if this optical device is compatible whit the External Sensor Head PAN5710VIS. llamb
(posted 2018-07-16 06:27:27.0) Thank you for contacting Thorlabs. The PAN5710VIS and all of our polarimeters are cage compatible, just like the CRM1P/M. You can screw four of our ER- series cage rods to the front of the polarimeter and then mount the CRM1P/M onto those four cage rods. photonspectroscopy
(posted 2017-06-29 11:51:16.93) Love this mount but having a similar issue with non-retraction of the micrometers. We find the set screw doesn't seem to do very much, and the micrometer version in the end is like the non-micrometer version, but without the locking feature. tfrisch
(posted 2017-09-01 10:36:32.0) Hello, thank you for contacting Thorlabs. It sounds like there is a problem with the spring that opposes the micrometer and the carriage has been pushed to the far end of the travel range. I will reach out to you directly about repairs. michael.vandegraaff
(posted 2017-06-04 18:48:13.743) This is one of my favorite products, but I have noticed a disturbing trend. The micrometer only works in one direction, there doesn't seem to be a restoring force to rotate the mount back with withdrawing the micrometer. the presence or absence of the setscrew also only seems to make a difference on some of the mounts.
I would also like to know how to re lubricate old mounts, I have a couple that are too stiff to be very helpful in a precision setup. tmorgus
(posted 2017-06-05 10:44:43.0) Hello Michael, We are going to look at the design and I am pulling inventory to check to make sure that what we have in stock is functioning properly. I'll also contact you to setup a replacement of your non-functioning mounts. Thank you for taking the time to let us know about your issues. Sincerely, Tyler, OptoMechanics Business Unit Leader johan.stigwall
(posted 2015-09-24 15:22:06.63) Does the precision rotation mount fit inside of a 60 mm cage system? Or would the adjustment knob hit one of the 60 mm rails? besembeson
(posted 2015-10-08 12:48:39.0) Response from Bweh at Thorlabs USA: The span of the CRM1P/M is about 59mm. If centered on the cage system through a 30mm to 60mm adapter plate, there will be 39mm (adjuster inclusive) on one side, which is more than the 30mm half width of the 60mm cage system. It will not interfere with the cage rods, but will extend outside which may or may not be okay for your application. user
(posted 2014-07-07 14:52:23.87) I would require a higher angular resolution, ideally 0.5 mrad (~0.1 arcmin). Is it possible to replace the manual micro-adjuster via a motorized version, for example the ZST206? cdaly
(posted 2014-08-06 05:42:15.0) Response from Chris at Thorlabs: None of your actuators would be compatible as a replacement for the micrometer in these rotation mounts due to the dimensions of the mounting barrel and the overall size. We do offer motorized rotation stages capable of holding one inch optics such as the PRM1(/M)Z8, though the entire continuous 360 degree would be controlled by a worm drive gear, eliminating the manual adjustment. sebastien.avila
(posted 2013-10-01 10:39:23.017) Hello,
We've lost the locking screw for fine ajustement and can't not find a replacement. what size of screw should we use? Is it metric or imperial for the CRM1P/M (M3, M4?)
Thank you very much.
S. AVILA tcohen
(posted 2013-10-01 21:04:00.0) Response from Tim at Thorlabs: This is a 6-32 setscrew. I will contact you to assist in a replacement. jjurado
(posted 2011-05-04 15:24:00.0) Response from Javier at Thorlabs to kielhorn.martin: Thank you very much for submitting your request. We actually do not have a recommended method for aligning the graduations on the rotation dial of the CRM1/M with the axis of a polarizer without touching the optic. If the polarization axis needs to be aligned after the optic is mounted, the optic itself needs to be held in place. Most optics remain clean if they are held using gloves or finger cots. For more optics handling and cleaning tips, see our tutorial here:
http://www.thorlabs.com/tutorials.cfm?tabID=26066
I will contact you directly for further support. kielhorn.martin
(posted 2011-05-04 12:45:30.0) I always just drop the polarizers into the mount and then tighten it in place. Obviously this doesnt align the polarizer axis with the graduation. Is there a trick, how one could rotate the graduation relative to the optics component without touching the optics? jjurado
(posted 2011-02-03 16:43:00.0) Response from Javier at Thorlabs to diego.soto: Thank you very much for submitting your inquiry. The CRM1P rotation mount is fitted with our 148-206ST micrometer drive, whose graduations are spaced 0.001" apart, with a total travel range of 1/4" (6.35mm). This linear travel translates into +/- 7 degrees of fine rotation on the CRM1P. Now, a Vernier scale with 5 arcmin resolution is also engraved onto the mount. The zero marking on the Vernier scale is your line of reference. If the zero marking is aligned with one of the graduations on the rotation dial (labeled every 2 degrees), then that is your reading. However, if the zero line falls in between two graduations on the rotation dial, then you look for the next line on the Vernier scale that is aligned with one on the rotation dial. That line (on the Vernier) is your arcmin measurement. The following link might help to better illustrate this: http://www.upscale.utoronto.ca/PVB/Harrison/Vernier/Vernier.html diego.soto
(posted 2011-02-03 16:52:04.0) Dear Sirs,
I´m new in the use of the CRM1P/M and I don´t quite understand how to read the rotation using the micrometer. I´ve been searching a guide in internet but couldn´t find any. I´ll appreciate any information on this matter. |
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 CT1 Cage Translator Stage and 1/4" Translation Stagesb |
| Additional Details | |||||||
| 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 | ||||||||
| Rotation Mounts for Ø1" Optics | ||||||
|---|---|---|---|---|---|---|
| Item # | LM1-A & LM1-B(/M) |
CRM1(/M) | CRM1L(/M) | CRM1P | KS1RS | K6XS |
| Click Photo to Enlarge |
  |
 |
 |
 |
 |
 |
| Features | Optic Carriage Rotates Within Mounting Ring | 30 mm Cage-Compatiblea | 30 mm Cage-Compatible for Thick Opticsa |
30 mm Cage-Compatible with Micrometera |
±4° Kinematic Tip/Tilt Adjustment Plus Rotation | Six-Axis Kinematic Mounta |
| Additional Details | ||||||
| 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 | ||||||
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) 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 | |||||||
| 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 | ||
Zoom- 360° of Continuous Rotation, Lockable
- 2° Graduations on Dial, Labeled Every 20°
- Accepts Ø1" (Ø25.4 mm) or Ø25.0 mm Optics
- CRM1(/M) Maximum Optic Thickness: 0.37" (9.4 mm)
- CRM1L(/M) Minimum Optic Thickness: 0.31" (7.9 mm)
- 8-32 (M4) Tapped Mounting Hole to Mount on TR Series Posts
The CRM1(/M) and CRM1L(/M) have a smooth rotation mechanism that allows for precise positioning of the rotation carriage and the mounts are compatible with the 30 mm cage system.
The CRM1(/M) is designed to mount Ø1" (Ø25.4 mm) optics up to 0.37" (9.4 mm) thick in an SM1-threaded rotation carriage. The optic is secured using the included SM1RR retaining ring (the SPW602 spanner wrench is ideal for tightening this retaining ring). For thicker optics, any of our SM1 series of lens tubes can be threaded into the carriage or the CRM1L can be used instead. The CRM1L(/M) is designed to mount Ø1" (Ø25.4 mm) optics with a minimum thickness of 0.31" (7.9 mm), but unlike the CRM1, the optic is retained in a double-bored rotation carriage using a setscrew.
These mounts are also mechanically compatible with Ø25.0 mm optics, but we only recommend this for applications in which the centration of the optics is not critical.
Zoom- 360° Coarse Rotation, Lockable
- 2° Graduations on Dial, Labeled Every 20°
- ±7° Precision Micrometer Adjustment
- Vernier Scale Provides 5 arcmin Resolution
- Accepts Ø1" (Ø25.4 mm) or Ø25.0 mm Optics up to 0.37" (9.4 mm) Thick
- 8-32 (M4) Tapped Mounting Hole to Mount on TR Series Posts
The CRM1P(/M) is designed to mount Ø1" (Ø25.4 mm) optics up to 9.4 mm thick in an SM1 threaded rotation carriage. The optic is secured using the included SM1RR retaining ring (the SPW602 spanner wrench is ideal for tightening this retaining ring). For thicker optics, any of our SM1 series of lens tubes can be threaded into the carriage. The smooth rotation mechanism on the CRM1P(/M) can be manually rotated to any position. When the rotation carriage is locked, the high-precision, backlash-free micrometer can then be used to fine tune the position of the rotation carriage over a range ±7°. The animation to the right illustrates how the CRM1P(/M) is used. The Vernier scale provides a resolution of 5 arcmin between consecutive marks. As the mount is rotated across the entire Vernier scale, there is a cumulative error of up to ±12.28 arcmin. The CRM1P(/M) is compatible with the 30 mm cage system and the 8-32 (M4) tapped mounting hole allows the rotation mount to be secured on a TR series post.
This mount is also mechanically compatible with Ø25.0 mm optics, but we only recommend this for applications in which the centration of the optics is not critical.
Zoom
The K6A1(/M) is a 0.5" x 1.44" platform designed to be mounted on the rotation ring on the CRM1 series (all versions) of 30 mm cage compatible rotation mounts featured above and the K6X six-axis kinematic mount. The K6A1 comes with a PM3 Small Clamping Arm (K6A1/M comes with PM3/M), hex key, and mounting screws. The K6A1 and K6A1/M have 6-32 and M4 x 0.7 tapped holes, respectively, on the mounting platform to secure the supplied clamping arm.
While using the K6A1(/M), the rotation mount needs to be the terminal element on the cage rods because the cage system is not large enough to allow for the rotation of the platform. If the rotation mount needs to be an interior cage component, consider building a 60 mm cage system frame around the rotation mount using two LCP02 cage plate adapters as shown in the image to the right. This will allow the platform to be rotated freely without interference from the cage rods while preserving the optical axis of the 30 mm cage system.
The SM1PM10 and SM1PM15 prism mounts are designed to accommodate the popular Glan-Taylor and Glan-Laser Polarizing Calcite Prisms. Their SM1 threading makes them compatible with the CRM1(/M) and CRM1P(/M) rotation mounts. The rotating cover allows the user to block the two side ports of the calcite prism when they are not required. To load a prims, unthread the prism cover, insert the prism, and tighten the setscrew. When mounting the SPM1PM10 or SPM1PM15 onto a rotation mount, first thread a retaining ring into the rotation mount to a depth of 3/16" (4.8 mm) and then thread on and tighten the prism mount. This will leave room so that the prism cover can rotate freely.
 Manual and Micrometer Driven Rotation Mounts |