16 mm Cage System Construction Rods
SR Series Cage Rods
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. This page offers cage assembly rods for our 16 mm Cage System. For 30 and 60 mm Cage Systems, please see our ER construction rods page. Please see the Cage Overview tab for more details on this widely adopted construction standard.
Standard Assembly Rods
Cage Couplers and Adapters
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SRSCA 1D Construction
Cage Rod Adapter
The SRSCA SR rod adapter allows for the end-to-end joining of two SR rods. It has an internal bore on one end that accepts Ø4 mm SR series rods. To join two rods, position the end of one rod inside the SRSCA, and lock it into place using the locking setscrew. Thread the other end of the SRSCA into the other rod (see photo at right).
3D Construction Using Cage Systems
These assembly rods are essential components when configuring cage systems in complex, multi-dimensional structures.
For 30 and 60 mm cage systems, 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.
Our swivel connectors can be configured to any arbitrary angle before being locked into place. The C3A connector, for 30 and 60 mm cage systems, is pictured to the right. We also offer the S3A connector for 16 mm cage systems.
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.
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The SRSCA SR rod adapters and ERSCA ER rod adapters are also useful for 3D construction in 16 mm cage systems or 30 and 60 mm cage systems, respectively. They can be used to connect two internally threaded cage components with SR (SRSCA) or ER (ERSCA) rods, and allow components to be easily added or removed from setups without causing misalignment. In the application shown to the left, four ERSCA adapters are used with ER rods 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. Instead, the threaded side of the ERSCA adapter is connected to the ST1XY-S translation mount. Each cage rod slides into the other side of each adapter and is secured in place with the setscrew.
The cage assembly components offered here can be used to couple 16 mm, 30 mm, and 60 mm cage systems. The following tables correspond to either the imperial or metric item list for the setup below.
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.
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.
These 16 mm cage rods are made from stainless steel and are designed for use with our Compact Cage Components. The 4-40 threaded setscrew 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.
Replacement setscrews can be purchased in packs of 50.
The SRSCA 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 a Ø4 mm SR series rod with its setscrew removed. The mounting stud collar must be tightened using the locking setscrew with a 5/64" (2 mm) hex key to hold the SR rod in place. On the other side of the adapter, there is an externally 4-40 threaded stud that can be threaded into the end of another SR series rod or 4-40 internally threaded cage component.
As seen in the images below, the SRSCA is particularly useful for connecting two internally 4-40 threaded cage system components with Ø4 mm SR series cage rods.
Thread the SR series cage rods directly into the KCB05 16 mm Right-Angle Kinematic Cage Mount as shown above. Then thread four SRSCA adapters into the SC6W Compact 6-Way Cage Cube. Finally, insert the Ø4 mm SR series rods into the internal bores on the SRSCA adapters and secure using the 2-56 locking setscrews.
The S1A cross coupler is designed for Thorlabs' Ø4 mm, SR series of cage rods. This coupler provides a method to attach a terminating SR rod at 90° to an SR rod that is passed through the clamp. Using two cap screws, the flexure design clamps onto both cage rods. The S1A is ideal for constructing 3D cage structures based on Thorlabs' 16 mm cage system, as shown in the example at right (for details, see the Construction tab).
The S3A swivel connector allows 16 mm SR 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.