Continuous Rotation Stage


  • Fine Pitch Worm Gear Provides 360° Continuous Rotation
  • Compatible with Prism Mounting Hardware
  • Vernier Scale Offers 5 arcmin Resolution

CR1

Continuous Rotation Stage

CR1A

General-Purpose Adapter Plate

PM3

PM4

Related Items


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Specifications
Item # CR1 CR1/M
Rotation Range 360°, Continuous
Load Capacity 25 lbs (11.3 kg)
Platform Size Ø1.70" (Ø43.2 mm)
Platform
Mounting Holes
8-32 (4 Places)
6-32 (8 Places)
4-40 (4 Places)
M4 x 0.7 (12 Places)
4-40 (4 Places)
Base Mounting Holes Two 1.00" (25.4 mm) Radial
Slots for 1/4"-20 (M6 x 1.0) Cap Screws
Overall Dimensions
3.14" x 2.10" x 1.00"
(79.7 mm x 53.4 mm x 25.4 mm)
CR1, Continuous Rotation Mount
Click to Enlarge

An MS1 Translation Stage is Mounted onto a CR1 Rotation Stage using two clearance holes for 4-40 cap screws.

Features

  • 360° Continuous, Backlash-Free Motion Provided by Fine Pitch Worm Gear
  • Vernier Scale Offers a Resolution of 5 arcmin
  • 24:1 Gear Ratio Provides 15° Stage Rotation per Revolution of Adjustment Knob
  • Application Tested to 25 lbs (11.3 kg) Vertical Load
  • Designed for Mounting MS1 and T12 Series Translation Stages (Using the CR1A(/M) Adapter Plate)
  • Compatible with Prism Mounting Hardware (See Below)

Thorlabs' CR1(/M) Rotation Stage includes a fine pitch worm gear that provides high-precision and backlash-free rotation. The stage is actuated using a stainless adjuster knob located on the side of the unit that provides 15° of stage rotation per revolution of the adjuster knob. The rotating platform contains an array of 8-32 (M4), 6-32, and 4-40 tapped holes for general mounting requirements. Two radially shaped 1/4" (M6) slots machined in the base provide flexible mounting options and are spaced for compatiblity with imperial and metric optical tables and breadboards.

The easy-to-read radial scale is marked in 2° increments and labeled every 10°. A side-located vernier scale improves resolution to 5 arcmin. The added ability to stack some of our translation stages on the rotation platform, and its 25 lbs (11.3 kg) capacity, make this stage useful in any laboratory.

CR1 SmartPack Packaging
Click to Enlarge

CR1 Packaging

Smart Pack

Item # % Weight
Reduction
CO2-Equivalent
Reductiona
CR1 40.48% 9.07 kg
CR1/M 40.48% 12.25 kg

Smart Pack

  • Reduce Weight of Packaging Materials
  • Increase Usage of Recyclable Packing Materials
  • Improve Packing Integrity
  • Decrease Shipping Costs

Thorlabs' Smart Pack Initiative is aimed at waste minimization while still maintaining adequate protection for our products. By eliminating any unnecessary packaging, implementing packaging design changes, and utilizing eco-friendly packaging materials for our customers when possible, this initiative seeks to improve the environmental impact of our product packaging. Products listed above are now shipped in re-engineered packaging that minimizes the weight and the use of non-recyclable materials.b As we move through our product line, we will indicate re-engineered packages with our Smart Pack logo.

  • Travel-based emissions reduction calculations are estimated based on the total weight reduction of packaging materials used for all of 2013’s product sales, traveling 1,000 miles on an airplane, to provide general understanding of the impact of packaging material reduction. Calculations were made using the EPA’s shipping emissions values for different modes of transport.
  • Some Smart Pack products may show a negative weight reduction percentage as the substitution of greener packaging materials, such as the Greenwrap, at times slightly increases the weight of the product packaging.

Reading a Vernier Scale on a Linear Main Scale

Vernier scales are typically used to add precision to standard, evenly divided scales (such as the scales on Thorlabs' rotation, goniometric, or translation mounts). A vernier scale has found common use in many precision measurement instruments, the most common being calipers and micrometers. The vernier scale uses two scales side-by-side: the main scale and the vernier scale. The direct vernier scale has a slightly smaller spacing between its tick marks owing to the vernier scale having N ticks for every N - 1 ticks on the main scale. 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 linear 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 instrument.

The 0 on the vernier scale is the "pointer" (marked by a red arrow in Figures 1 - 5) 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 pointer lines up with the main scale’s 75.6, the reading from Figure 1 is 75.60 (in whatever units the instrument measures).

That is essentially all there is to reading a vernier scale. It's a very straightforward way of increasing the precision of a measurement instrument. To expound, let’s look at Figure 2. Here we see that the pointer is no longer aligned with a line on the main scale, but instead it is slightly above 75.6 and 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 this vernier scale is 10% smaller than the main scale, moving the vernier scale by 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 scale 7 (marked with a blue arrow) is very closely aligned to the main scale, giving a precision measurement of 75.67. However, the vernier scale 7 is very slightly above the main scale mark, and we can see that the vernier scale 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 instrument.

Figure 1: Vernier scale measuring 76.0
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 instrument measures).
Figure 1: Vernier scale measuring 76.0
Click to Enlarge

Figure 2: The red arrow indicates the pointer and the blue arrow indicates the vernier line that matches the main scale. This scale reads 75.65.
Figure 1: Vernier scale measuring 76.0
Click to Enlarge

Figure 3: 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.

 

Reading a Vernier Scale on a Rotating Main Scale

The vernier scale may also be used on rotating scales where the main scale and vernier scale do not share units. Figures 4 and 5 show a vernier scale system for two different situations where the main scale is given in degrees and the vernier scale has ticks every 5 arcmin (60 arcmin = 1°). In each case, the scale on the top is the main scale, while the small scale on the bottom is the vernier scale.

In Figure 4 we see the pointer is lined up directly with the 341° line. Notice that the only other vernier scale tick marks that line up well with the main scale are ±60 arcmin. Since the pointer lines up with the main scale at 341°, the reading from Figure 4 is 341.00°.

There are two ways to determine the reading if the zero on the vernier scale line is between two lines of the main scale. For the first method, take the line on the left side of the pointer on the vernier scale and subtract that value (in arcmin) from the value on the main scale that is to the right on the main scale. As an example, in Figure 5 the vernier pointer is between 342° and 343°; using the left blue arrow of the vernier scale results in 343° - 15 arcmin = 342.75°. The second method is to take the reading from the blue arrow on the right side of the vernier pointer and add that value to the lower value from the main scale; reading the right blue arrow in Figure 5 results in 342° + 45 arcmin = 342.75°.

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. Vernier scales, whether they are direct or retrograde*, are read in the same fashion.

*A retrograde vernier scale has a larger spacing between its tick marks with N ticks for every N + 1 ticks on the main scale.

Figure 1: Vernier scale measuring 341.00°.
Click to Enlarge

Figure 4: An example of a vernier scale where the main scale and the vernier scale are in different units (degrees and arcmins, respectively). The red arrow indicates the pointer. This scale reads 341.00°.
Figure 2: Vernier scale measuring 342.75°.
Click to Enlarge

Figure 5: The red arrow indicates the pointer and the blue arrows give the precision value from the vernier scale.
This scale reads 342.75°.

Posted Comments:
Andrey Kuznetsov  (posted 2024-05-06 17:29:28.183)
I have multiple CR1 stages and they suffer from multiple problems. An optical post mounted on the stage wobbles pretty badly, there is also severe backlash, and the worm drive does not operate smoothly, it would get more difficult to turn within certain ranges. Grease has also leaked out of the stages.
cdolbashian  (posted 2024-05-10 04:26:04.0)
Thank you for reaching out to us with this inquiry Andrey. I have contacted you directly to have you expound on these issues and share your experience with us.

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 Stagesb
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
LRM1
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-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
  • 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)
LCRM2A(/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
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) 0.52" (13.2 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

Manual Rotation Stages

Manual Rotation Stages
Item # RP005(/M) PR005(/M) MSRP01(/M) RP01(/M) RP03(/M) QRP02(/M)
Click Photo
to Enlarge
Continuous Rotation Mount
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) PDR1C(/M) PDR1(/M) PDR1V(/M) PDXR1(/M)
Click Photo
to Enlarge
DDR25 PDR1C PDR1 PDR1V PDXR1
Features Compatible with
SM05 Lens Tubes,
16 mm Cage System, &
30 mm Cage System
Compatible with
16 mm Cage System
Compatible with
SM05 Lens Tubes &
30 mm Cage System
Vacuum-Compatible;
Also Compatible with
SM05 Lens Tubes &
30 mm Cage System
Compatible with
SM05 Lens Tubes &
30 mm Cage System
Additional Details

Motorized Rotation Mounts and Stages with Central Clear Apertures
Item # K10CR1(/M) PRM1Z8(/M)a DDR100(/M) ELL14 HDR50(/M)
Click Photo
to Enlarge
ELL14
Features 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
  • 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.
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Continuous Rotation Mounts


Click for Details

CR1 Mechanical Drawing
  • 360° Continuous, Backlash-Free Motion Provided by Fine Pitch Worm Gear
  • Vernier Scale Offers a Resolution of 5 arcmin
  • 24:1 Gear Ratio Provides 15° Stage Rotation per Revolution of Adjustment Knob
  • Application Tested to 25 lbs (11.3 kg) Vertical Load
  • Designed for Mounting MS1 and T12 Series Translation Stages (Using the CR1A(/M) Adapter Plate)
  • Compatible with Prism Mounting Hardware

The CR1(/M) rotation stage includes a fine pitch worm gear that provides high-precision and backlash-free rotation. The stage is rotated via a polished stainless steel adjuster knob located on the side of the unit. The easy-to-read radial scale is marked in 2° increments and labeled every 10°. A side-located vernier scale provides resolution to 5 arcmin.

The rotating platform contains an array of 8-32 (M4) and 4-40 tapped holes. In addition, eight 6-32 (M4) taps are located 17.5 mm from the center of the platform; using a PM3(/M) clamping arm in one of these taps will locate the clamping arm's nylon-tipped setscrew directly above the center.

The CR1(/M) has two radially shaped 1/4" (M6) slots machined in the base so that it can be mounted to an optical table or breadboard.

The rotation stage is capable of operating with a mounted load of up to 25 lbs (11.3 kg). MS1 series and T12 series translation stages can be mounted on top of the rotating platform with the use of a CR1A(/M) adapter plate.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Imperial Price Available
CR1 Support Documentation
CR1Continuous 360° Rotation Stage with 8-32, 6-32, and 4-40 Mounting Taps
$381.32
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+1 Qty Docs Part Number - Metric Price Available
CR1/M Support Documentation
CR1/MContinuous 360° Rotation Stage with M4 and 4-40 Mounting Taps
$381.32
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Rotation Stage Adapter

CR1A, Continuous Rotation Mount Adapter
Click to Enlarge

A CR1A Adapter is used to secure a T12X Mini Translator onto a CR1 Rotation Stage using two 2-56 cap screws.

The CR1A(/M) adapter can be used to secure select Thorlabs mounts to the CR1(/M) Rotation stage. The adapter is equipped with four 6-32 (M4) taps, one 1/4"-20 (M6) tap, six 4-40 taps (two 4-40 and four M3 on the metric version), eight 2-56 taps (four 2-56 and four M2 on the metric version), and four #6 (M4) clearance holes. The following table lists mounts that may be secured to the the CR1(/M).

The CR1A(/M) adapter is attached to the CR1(/M) stage via the #6 (M4) clearance holes with four 6-32 (M4) cap screws (included). The photo to the right shows a T12X translation stage mounted on the CR1A adapter through two #2 (M2) clearance holes in the bottom of the T12X stage.

Mounts Compatible with CR1A(/M) Adapter
Mount Description
PM3(/M), PM4(/M), and PM5(/M) Clamping Arms
PH Series Post Holders
T12 Series 1/2" Mini Translators
GN Seriesa Small Platform Goniometers*
  • Note: The CR1A(/M) adapter plate is not compatible with our GNL series Large Platform Goniometers.
Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Imperial Price Available
CR1A Support Documentation
CR1AAdapter Plate for CR1 Rotation Stage
$29.10
Today
+1 Qty Docs Part Number - Metric Price Available
CR1A/M Support Documentation
CR1A/MAdapter Plate for CR1/M Rotation Stage
$29.10
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Clamping Arms


Click for Details

Mechanical Drawings
  • Provide Clamping Force for Our Platform Mounts
  • Threaded Hole on Top and Threaded Stud on Bottom of Post
    • 6-32 Threads on PM3 and PM4
    • 8-32 Threads on PM5
    • M4 x 0.7 Threads on All Metric Versions
  • Maximum Optic Heights from 0.97" to 1.65" (24.6 mm to 41.8 mm)
  • Extension Posts Available to Increase Max Optic Height
    • PM3SP(/M) with PM3(/M): Hold Optics up to 2.21" (56.1 mm) Tall
    • PM4SP(/M) with PM4(/M): Hold Optics up to 3.61" (91.7 mm) Tall

Click to Enlarge

Clamping Arm Extension Posts with Metric Indicator Groove

Thorlabs' Clamping Arms provide clamping force to secure optics to our kinematic platform mounts, stages, and V-clamps. The PM3(/M) accommodates optics up to 0.97" tall and features a 0.69" center-to-center distance between the post and the nylon-tipped setscrew that holds the optic. The PM4(/M) accommodates optics up to 1.61" and features a 1.16" center-to-center distance between the post and the nylon-tipped setscrew. The maximum optic height of the PM3(/M) or PM4(/M) Clamping Arms can be extended using our PM3SP(/M) or PM4SP(/M) Extension Posts, respectively. These extension posts are identical to the posts included in each complete clamping arm. Each clamping arm features 6-32 (M4 x 0.7) threads. The PM3 and PM4 can be mounted in 8-32 tapped holes by using the AS6E8E thread adapter, which features internal 6-32 threads and external 8-32 threads. This thread adapter has an outer diameter of 0.24", which is the same as the PM4SP extension post and the post included with the PM4 clamping arm. This allows the clamping arm to be adjusted across the seam between either post and the adapter. The smaller diameters of the included post for the PM3 clamping arm and the PM3SP extension post cause the thread adapter to act as a stop for the clamping arm.

The PM5(/M) clamping arm is made entirely from heat-treated stainless steel, which helps maintain stability in fluctuating temperatures and provides vacuum compatibility. This clamping arm is recommended for use with the POLARIS-K1M4(/M), but it can be used with any platform mount or stage that has one or more 8-32 (M4 x 0.7) tapped holes. The PM5(/M) can hold optics up to 1.65" tall, and the distance from the post center to the contact point that holds the optic is 0.90".

Each clamping arm is attached to its post using a flexure mechanism that locks with a 5/64" (2.0 mm) balldriver or hex key. The setscrew on top of the clamping arm also accepts a 5/64" (2.0 mm) balldriver or hex key in order to clamp down on the optic. The post includes a through hole which can be leveraged for added torque when tightening down the post. Please see the diagram above for additional information.

Based on your currency / country selection, your order will ship from Newton, New Jersey  
+1 Qty Docs Part Number - Imperial Price Available
PM3 Support Documentation
PM3Small Adjustable Clamping Arm, 6-32 Threaded Post
$21.86
Today
PM3SP Support Documentation
PM3SPCustomer Inspired! Extension Post for PM3 Clamping Arm, 6-32 Threaded
$6.06
Today
PM4 Support Documentation
PM4Large Adjustable Clamping Arm, 6-32 Threaded Post
$26.73
Today
PM4SP Support Documentation
PM4SPCustomer Inspired! Extension Post for PM4 Clamping Arm, 6-32 Threaded
$6.06
Today
PM5 Support Documentation
PM5Stainless Steel Adjustable Clamping Arm, 8-32 Threaded Post
$66.38
Today
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PM3/M Support Documentation
PM3/MSmall Adjustable Clamping Arm, M4 x 0.7 Threaded Post
$21.86
Today
PM3SP/M Support Documentation
PM3SP/MCustomer Inspired! Extension Post for PM3/M Clamping Arm, M4 x 0.7 Threaded
$6.06
Today
PM4/M Support Documentation
PM4/MLarge Adjustable Clamping Arm, M4 x 0.7 Threaded Post
$26.73
Today
PM4SP/M Support Documentation
PM4SP/MCustomer Inspired! Extension Post for PM4/M Clamping Arm, M4 x 0.7 Threaded
$6.06
Today
PM5/M Support Documentation
PM5/MStainless Steel Adjustable Clamping Arm, M4 Threaded Post
$66.38
Today