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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. Please see the Cage Overview tab for more details on this widely adopted construction standard.
Standard Assembly Rods Our precision-ground cage assembly rods are basic building blocks used to construct optical systems. These rods are most commonly used as precision guides for our cage assembly plates and are available with a 6 mm diameter for 30 mm or 60 mm cage systems. Each rod has a removable 4-40 stud in each end, and all rods are designed to be stackable. An infinite array of systems can be assembled when used in conjunction with our cage plates and lens tubes. Please see the Construction tab for more information on building cage systems.
Cage Couplers and Adapters The 30 mm cage rod adapters offered here enable the easy addition or removal of components from cage assemblies. Using these cage rod adapters, two internally threaded cage components can be connected end to end.The 30 mm cage rod couplers provide a method of connecting rods at 90° angles.
Swivel Coupler and Connector The C2A swivel coupler and C3A swivel connector can be used to connect cage assemblies at arbitrary angles. These parts are made from stainless steel and provide an extremely rigid structure.
Right-Angle Rod and Spacers The ER90C right-angle rod provides rigid "T" connection, while the ER90A and ER90L right-angle spacers maintain perfect rod separation for cage assemblies. Together, these components increase strucural rigidity when used with inline applications.
Cage Plate Stops ERCPS Cage Plate Stops provide a convenient means for marking the position of cage plates along cage rods.
The ERSCA ER rod adapter allows for the end-to-end joining of two ER rods. It has an internal bore on one end that accepts Ø6 mm ER series rods. To join two rods, position the end of one rod inside the ERSCA, and lock it into place using the locking setscrew. Thread the other end of the ERSCA into the other rod (see photo at right).
These assembly rods are essential components when configuring cage systems in complex, multi-dimensional structures.
The S3A and C3A swivel connectors can be configured to any arbitrary angle before being locked into place (see photo at right).
The ER90C right angle rods offer a fixed 90° connection to a cage system (see photo to left). Using the ER90A spacer rod for 30 mm cage systems and the ER90L spacer rod for 60 mm cage systems will ensure center-to-center spacing. Alternatively, a cage cube can be used to create a rigid 90° connection.
When constructing complex optomechanical cage assemblies, it is sometimes necessary to couple one cage subsystem to another. Between the S1A cross coupler for 16 mm cages, the C1A cross coupler for 30 and 60 mm cage systems, and the C2A swivel coupler with 180° swing, virtually any configuration can be achieved.
The ERSCA ER rod adapter is also useful for 3D construction. As shown in the image to the right, the ERSCA can be used to connect two internally threaded cage components with ER rods. In the application shown to the left, cage rods are used to connect a 30 mm cage cube to an ST1XY-S micrometer-driven, XY translation mount. The four cage rods are directly threaded into four holes in the cage cube. Since the other end of each cage rod is internally threaded, they cannot be directly threaded into the translation mount.
As shown to the left, the threaded side of the ERSCA adapter is connected to the ST1XY-S translation mount. The cage rod slides into the other side of the adapter and is secured in place with the setscrew. Using the ERSCA adapters, components can easily be added to or removed from setups without causing misalignment.
Application Idea
The cage assembly components offered here can be used to couple 16 mm, 30 mm, and 60 mm cage systems. The parts used in the following setup are listed below:
An example of the standard cage plate measurements determining cage system compatibility.
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 to right). 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.
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.
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.
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.
Really glad to finally see 4-packs of ER rods for sale! It makes ordering much simpler.
Poster: jlow
Posted Date: 2013-03-27 10:28:00.0
Response from Jeremy at Thorlabs: Thank you for your feedback on this. We continually look at our sales statistics so that we can identify ordering trends. In this case a large number of people order four ER rods at a time. To make life easier we thought it would be good to offer them that way. It will also allow us to reduce packaging waste.
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For use with Our Standard 30 mm and 60 mm Cage Systems
Available Individually in Lengths Ranging from 1/4" to 24"
Packs of 4 Also Available for 1/2" to 8" Lengths
Ø6 mm Precision-Ground Stainless Steel
4-40 Removable Setscrew at Both Ends
These 30 and 60 mm cage rods are made from stainless steel. The 4-40 threaded stud at each end of the cage rod can be removed, leaving a 4-40 tapped hole. This allows multiple cage rods to be connected end-to-end. As part of our sustainability initiatives to reduce packaging waste, we offer our most popular sizes in packs of four.
Graduated ER Rods for 30 mm and 60 mm Cage Systems
Engraved Scale (Increments of 1 mm) for Accurate Adjustments
For Use with Standard 30 mm and 60 mm Cage Systems
Available in Two Lengths: 4" and 6"
Ø6 mm Precision-Ground Stainless Steel
4-40 Removable Setscrew at Both Ends
These graduated ER rods are identical to the 4" and 6" ER Rods above, but feature an engraved scale along the side. The rods have short tick marks every 1 mm, long tick marks every 5 mm, with a straight vertical line along the rod's entire length. The engraved rods simplify alignment issues, especially in complicated setups with multiple components and integrated cage systems. For custom lengths, please contact Technical Support.
Easily Add or Remove Components from Cage Assemblies
The ERSCA is a stud adapter that will allow any cage assembly to be easily separated when adding or removing components. This adapter has an internal bore on one end that accepts an internally threaded Ø6 mm ER series rod. Once the rod is positioned inside of the adapter, a 4-40 locking setscrew can be used to hold the rod in place. On the other side of the adapter, there is an external 4-40 threaded stud that can be threaded into the end of another ER series rod or 4-40 internally-threaded cage component.
ERCPS Cage Plate Stops snap onto cage rods without any disassembly of the cage system. Click to Enlarge
ERCPS Cage Rod Stops can mark the position of cage components. Click to Enlarge
Marks the Position of Cage Components
Flexure Clamping Mechanism
Sold in Packs of Four
ERCPS Cage Plate Stops mark the position of a cage plate, allowing it to be moved and repositioned in a cage system. These clamps are 0.14" thick and are compatible with Ø6 mm ER rods for 30 mm and 60 mm cage systems. Utilizing a flexure design, the clamps are secured in place using an 0.05" hex key. They can be easily clamped onto the middle of a cage rod without removing other components.
ER Rod Swivel Coupler for 30 mm and 60 mm Cage Systems
The C2A swivel coupler enables the connection of cage assemblies at arbitrary angles. They are constructed from stainless steel, adhere to close tolerances, and provide an extremely rigid structure.
ER Rod End Swivel Connector for 30 mm and 60 mm Cage Systems
The C3A swivel connector allows 30 mm or 60 mm ER cage assembles to be connected at a range of angles up to ±90° from the system normal. Made from stainless steel, these lockable couplers result in very rigid structures.
ER Right-Angle Rod and Spacers for 30 mm and 60 mm Cage Systems
ER90C Provides Rigid "T" Connection for Cage Assembly
ER90A and ER90L Maintain Perfect Rod Separation for Cage Assemblies
Increases Structural Rigidity When Used with Inline Applications
Insert the ER90C right-angle rod between two ER rods to form a "T" connection point. To form a complete 90° cage assembly a ER90A or ER90L spacer rod should be used for 30 mm or 60 mm cage systems, respectively. The spacer rod is placed between two ER90C right-angle rods to maintain the proper center-to-center spacing of the cage system (see image at right). Alternatively, a 30 mm or 60 mm cage cube can be used to create the rigid right-angle connection.