Post Holder Bases
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The height of any component mounted on a BA2(/M) base can be increased in increments from 0.010" (0.25 mm) to 2" (50 mm) using a Mounting Base Spacer. Here a BA2 base is shown with a BA2S7 1" Mounting Spacer
Thorlabs offers our standard anodized aluminum bases in a variety of sizes to best utilize space on an optical breadboard. For close positioning of components, our BA1S(/M) base features the smallest footprint. For increased stability while maintaining a small footprint, the two-slotted BA1(/M) is a good option. For the greatest stability, consider either our BA2(/M) or BA3(/M) base, each of which is twice the width of our BA1(/M) base. The BA2(/M) features two straight slots, while the BA3(/M) has two radial slots for ± 45 degrees of manual rotation. As our longest standard base, the BA1L(/M) provides 1.44" (36.6 mm) of linear manual positioning and can be secured to an optical breadboard by two screws, even when oriented at varying angles with respect to the tapped hole pattern (see photo to the right).
These vacuum-compatible bases are constructed from 6061-T6 aluminum, and are compatible, as delivered by Thorlabs, with vacuum environments down to 10-6 Torr. With additional cleaning and processing, they can be used at even lower pressures, only limited by the outgassing rate of the aluminum (see the table to the right).
These bases are chemically cleaned and prepared for vacuum applications before packaging. In contrast to the standard black anodized finish of our other bases, which is unsuitable for high vacuum applications, this cleaning method creates a ~20 Å thick, non-porous layer of aluminum oxide which is resistant to outgassing and contaminants.
These bases are packaged in double airtight bags for cleanroom and vacuum chamber applications.
The anodized aluminum BA2T2 complements our popular line of standard mounting bases. It features a 1" long, couterbored slot along the center length that contains a 1/4"-20 (M6) threaded stud ideal for use with our Ø1/2" post holders. This slot provides for two-dimensional positioning of any attached optical component. To reposition a post holder on the base, loosen it, slide it into the desired position, and retighten it to the base. The base also contains two 1/4"-20 (M6) counterbored holes located on either side of the 1" long slot.
These anodized aluminum magnetic bases are modeled after our popular standard bases but are enhanced by bottom-mounted rare earth magnets, which provide the ability to temporarily secure components during the setup process. The force from these magnets is strong enough to help prevent accidental movement of components, while still allowing for easy repositioning. The full functionality of these bases can only be achieved when using them on a magnetic table or breadboard; however, they can function as a standard base on non-magnetic surfaces as well.
Each base attaches to a post holder via cap screws that fit within a bottom-located 1/4" (M6) counterbored hole. For final attachment to an optical breadboard, each base features at least one slot for a 1/4-20 (M6) cap screw. The BA1SR provides one 1.10" (27.9 mm) slot and allows for the smallest footprint. For increased stability while maintaining a small footprint, the BA1R provides two 0.81" (20.1 mm) slots. Finally, for the most support, the BA2R features two 1.25" (31.8 mm) slots. In addition, the BA2R comes with four bottom-located M3 counterbored holes for 34 mm rail mounting.
The BA2F mounting base features a Ø1" (Ø25 mm) double bore and flexure clamping mechanism. This clamp allows for both height and rotational adjustment of both Ø1/2" post holders and Ø1" optical posts. It is actuated by a 3/8"-24 (M10 x 1.5) clamping screw with 3/16" (5 mm) hex key. A permanent steel insert at the end of the flexing mechanism prevents damage to the clamp from overtightening.
An RM1A or RM1B Ø1" post collar can be used with Ø1" posts or Ø1/2" post holders as a hard stop for repeatable height adjustment. The base also features an 8-32 (M4) tapped hole near the double bore. With a cap screw or setscrew inserted into this hole, the post collar can also function as a rotational stop (see photo on the top right).
Note: The flexure mechanism will contact the steel insert when mounting Ø1/2" post holders, since they are slightly smaller in diameter than Ø1" posts. This is normal operation and will not harm the mounting base.
Our 360° swivel base adapter fits all standard Ø1/2" post holders with 1/4"-20 (M6) mounting holes and minimizes the amount of time it takes to assemble an optical system. In addition, the swivel design is ideal for applications that require a large number of components to be packed into a small area. When our Ø1/2" post holders are used with the UPHA adapter, the combination is nearly that of our very popular Universal Post Holders. This anodized aluminum UPHA adapter has the benefit of compatibility with any of our existing Ø1/2" post holders but does not offer the same height flexibility of the UPH series post holders, which allow the post to be lowered all the way to the table.
Thorlabs' RSPC Position Retainer is used to realign bases, and other squared-off components, that have been removed from an optical system. It acts as a marker on the breadboard or optical table in the event that you need to remove a component from your set-up. The three white dots engraved on the surface of the retainer mark the three points that contact your part. The two dots on the outer arms can be used independently as contacts for posts. For more information on using the anodized aluminum RSPC with a post, click here.
Note: The RSPC Position Retainer can also be secured to an optical table or breadboard via the CL6 clamp. This clamp is useful in situations where the RSPC cannot be placed directly over a hole in the table. The photos below illustrate the RSPC being secured to an optical table with both an 8-32 cap screw and the CL6 clamp.
RSPC Mounted Directly to Optical Table
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RSPC Secured by CL6 Clamp
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