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Adjustable SM2 Lens Tubes
Non-Rotating Zoom Housing
SM2V10 Adjustable Lens Tube Connected to a Ø2" Lens Tube and Post-Mounted Using an SM2RC Slip Ring
Adjustable Lens Tubes
Adjustable Collimation Adapter
Adjustable lens tubes allow for the adjustment of an optic's position along the optical axis within a lens tube system. Our adjustable lens tubes with extended external threads are designed to house a Ø2" optic and offer up to 1.31" (33.3 mm) of rotating optic travel. The SM2NR1 Zoom Housing provides 1.16" (29.5 mm) of non-rotating adjustment at 17 mm per revolution for a Ø1" optic; it can be mounted between two fixed lens tubes. The SM2F Adjustable Collimation Adapter provides 20 mm of non-telescoping, rotating adjustment of a Ø2" (Ø50 mm) collimation optic.
Thorlabs' Threading Specifications
Thorlabs' lens tubes utilize a series of non-standard threadings. Threading specifications are given below for our SM threadings utilized in our lens tube and cage system components so that you can machine mating components to suit your application. We also offer products with C-Mount and RMS threadings, and the specifications for these threadings are also given below. Please note that other manufacturers may have different tolerances for these threads. For other thread specifications that are not listed here, please contact Tech Support.
Simplified Mechanical Drawing
These SM2-threaded (2.035"-40) adjustable lens tubes have an extra-long externally threaded section, allowing Ø2" optics to be positioned along the optical axis of a Ø2" lens tube system. To operate, mount the optic in the internally threaded section using the included SM2RR retaining ring. Then thread the adjustable lens tube into a compatible (i.e., matching threads) lens tube or SM2-threaded lens mount until the optic is at the desired position. Use the included SM2NT locking ring to fix the position of the lens tube.
For applications where it is difficult to reach the locking ring by hand, we offer the SM2NT1 Slotted Locking Ring and SPW503 Spanner Wrench. This locking ring contains slots for the 2¼" end of the spanner wrench.
These adjustable lens tubes are an ideal solution for fine tuning of the first and last lenses in a lens tube system. Although a lens tube can be attached to the front of the adjustable lens tube, it should only be done after the position has been fixed, since this lens tube will need to be free to rotate and translate if the position is changed. Like our standard lens tubes, these adjustable lens tubes are made of black anodized aluminum.
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The SM2NR1 zoom housing can be mounted between two fixed SM2 lens tubes.
Thorlabs' SM2NR1 provides 1.16" (29.5 mm) of non-rotating adjustment for Ø1" optics in a lens tube system. The SM2NR1 is SM2-threaded (2.035"-40) and can be mounted between two fixed lens tubes. It contains an internally SM1-threaded (1.035"-40) cell where optics are installed using the included SM1RR retaining ring. A double helical mechanism moves the optic back and forth while restricting any rotational movement.
This Adjustable Collimation Adapter provides 20 mm of non-telescoping, rotating translation for a Ø2" (Ø50 mm) optic with a clear aperture of Ø47.0 mm. As seen in the drawing to the right, the input and output apertures of the adapter are equipped with removable thread adapters. The input adapter is externally SM1 threaded (1.035"-40) and internally SM2 threaded (2.035"-40); removing it provides compatibility with SM2-threaded components. The output thread adapter is externally M62 x 0.75 threaded and internally SM2 threaded. We also offer versions with pre-mounted aspheric condensers here. The SM2F should be used at temperatures from 15 to 60 °C (non-condensing).
The inner carriage can be translated along the Z-axis by turning the adjustment ring (engraved with the Item # in the photos to the left) and locked into position by turning the locking screw on the side of the adjustment ring with a 2 mm (5/64") hex key. While the lens cell will rotate within the adapter housing when translated, the mounting threads on the housing remain fixed, allowing the SM2F to be mounted between fixed lens tubes. Lines with a 2 mm spacing are engraved on the housing as a rough guide for how far the carriage has been translated. Each collimation adapter also includes a 10-mm-thick, SM2-threaded retaining ring that allows an aspheric condenser lens to be mounted with our SPW604 Spanner Wrench.
Inserting or Removing Optics