Compact Kinematic Mounts

Hardened Steel Inserts Reduce Wear
Brass Sleeves for Smooth Adjustment
100 TPI Precision Adjusters

Hex Head
Adjuster

KMSS

KMS

Removable Knobs
for Tamper Resistance

KMS

Post
Not Included

MH25T

Ø1" Mirror Holder

KMS with MH25
Ø1" Mirror Holder

Application Idea

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Overview
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The extra mounting hole on the back of the KMSS Compact Mount can be used for positioning in confined spaces.

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Mirrors can be Mounted to the KMS(/M) or KMSS(/M) using the MH12, MH25, or MH25T Mounting Adapters (Sold Below).

Features

Compact Profile is Ideal for Space Constrained Applications
Hardened Steel Inserts at Kinematic Contact Points to Reduce Wear
Tapped Holes for Vertical or Horizontal Post Mounting
Adapters for Mounting Ø1/2" or Ø1" Optics
Versions Available With or Without Knurled Knobs

The KMS(/M) and KMSS(/M) mounts are compact, general-purpose, two-adjuster kinematic mirror mounts. The adjustment screws on the KMS have a 5/64" hex socket, which can be accessed through the removable knobs. The slimmer design of the KMSS results from removing the adjuster knobs and shortening the adjuster screws to their minimum length. Therefore, a 5/64" hex key is required for adjustments to the KMSS mount.

Both mounts offer an angular displacement range of ±4° with an adjustment per revolution of 15 mrad/rev. They feature two 8-32 (M4) threaded holes on the bottom and back of the mount for vertical or horizontal Ø1/2" post mounting. A 4-40 tapped hole is also included on the front of the mount for attaching our MH12, MH25, and MH25T Mirror Holders (sold below). Both mounts are fabricated from black anodized aluminum.

Mirror Holders
The front plate on each of our compact mirror mounts is equipped with a 4-40 mounting hole that directly accepts either the Ø1/2" mirror holder (MH12) or the Ø1" mirror holders (MH25 or MH25T). The MH12 has a nylon-tipped setscrew that can accommodate Ø1/2" mirrors that are at least 0.10" (2.5 mm) thick. The MH25 and MH25T are two-piece adapters that mount Ø1" mirrors using an internally threaded retainer. The MH25 mounts mirrors from 2.5 mm (0.10") to 6.1 mm (0.24") thick, while the MH25T mounts mirrors from 6.0 mm (0.23") to 10.0 mm (0.39") thick.

Posted Comments:

user (posted 2020-09-30 15:19:49.173)

Hi Do you have any data of the temperature and long term stability of the KMS/M compared to the polaris range?

llamb (posted 2020-10-08 01:33:30.0)

Thank you for contacting Thorlabs. While we do not currently have thermal stability data for the KMS/M specifically, we have some comparable data for very similar KM- series aluminum kinematic mounts that we can provide. I will reach out to you by email directly with this data. If thermal stability is a concern for your application, we would recommend choosing a Polaris kinematic mount.

Itamar Meyer (posted 2019-08-28 19:46:55.59)

I have a difficult time figuring out what the rotational axis are, As far as I can see, the only axis of rotation is a diagonal line between the 4-40 TPI adjusters, Am I wrong? For I need pitch and roll adjustments. What use are the screws on the opposite side? The ones who are attached to the spirngs, are they also for adjustments? Thanks.

YLohia (posted 2019-08-28 10:47:38.0)

Hello, thank you for contacting Thorlabs. This kinematic mount offers pitch and yaw adjustment. The set screws on the opposite side are used to secure the extension springs to the front plate and are not intended for adjustment.

user (posted 2019-05-23 09:53:36.74)

It would be great if you made these little holders for 1.5" optics, to make a low-cost 1.5" kinematic mirror mount. I would buy lots!

llamb (posted 2019-05-23 10:30:51.0)

Thank you for your feedback. I have added this idea to our internal product forum for further review.

Joey Lawson (posted 2019-03-19 14:15:25.69)

Can you confirm whether or not the KMSS mount would be compatible with the PIAK10 piezoelectric inertia actuator?

llamb (posted 2019-03-20 02:09:21.0)

The KMSS mount is not compatible with the PIAK10 acutator. The KMSS features 3/16"-100 threaded adjuster screws, while the PIAK10 features a 1/4"-80 threaded barrel.

bernd.steffen (posted 2016-03-24 11:01:59.897)

Can you add a 4-40 thread right in the axis of the ball joint to make the mount "gimbal" (without glue, as I do it now...)? And do you also have a "left handed" version?

besembeson (posted 2016-03-24 03:09:36.0)

Response from Bweh at Thorlabs USA: We don't have a left handed version at this time but we will review this option. I will contact you about your application and the gimbal construct.

user (posted 2015-01-22 16:29:40.76)

Hi, I agree with the other people below. The upper mounting hole of KMS/M and KMSS/M should be M4 (or at least M3), not 4-40. There's no screw adapter available for male 4-40 to M4 (or M3), which makes this product hard to use.

cdaly (posted 2015-01-22 04:09:32.0)

Response from Chris at Thorlabs: The #4-40 threaded hole is to provide compatibility with the existing optic holders such as MH12, MH25, and MH25T. We will discuss internally the possibility of making the change to an metric threaded hole, but this would require a new version of each of these items as well.

adam.wyatt (posted 2014-05-07 10:05:20.22)

Is it possible to supply the KMSS/M (and similar mounts) with M4 tapped holes on the centre of the front plate, instead of the 4-40 UNC threaded hole already there.

jlow (posted 2014-05-07 11:27:49.0)

Response from Jeremy at Thorlabs: We can do this. We will contact you directly regarding the quote.

hambitza (posted 2013-05-05 06:15:15.187)

I am searching for the resolution for the KMS/M mount in mrad per revolution. On its catalog page 249 there is the resolution only for other components from the KM... series given.

cdaly (posted 2013-05-06 11:04:00.0)

Response from Chris at Thorlabs: Thank you for using our feedback tool. Both the KMS and KMS/M use 3/16"-100 adjusters, which results in a resolution of 14.7 mrad/revolution at the nominal position.

klee (posted 2009-10-15 10:28:33.0)

A response from Ken at Thorlabs to weronika.zaperty: The #4-40 thread has a 0.112" (2.8448mm) diameter and 40 TPI (threads per inch), which translate to a 0.635mm thread pitch. McMaster Carr has numerous #4-40 screws available.

weronika.zaperty (posted 2009-10-15 08:12:27.0)

Hi:) i have a question about thread of KMS/M element - at the documentation there is written #4-40 - how it can be describe in metric units? where can I buy such threads? best regards, Weronika Zaperty

klee (posted 2009-08-26 11:11:55.0)

A response from Ken at Thorlabs to bmcpherson: We can make the KMSS with F19SS038 screws as a special. Please let us know the quantity and we can send you a quote.

whyemail (posted 2009-08-25 21:57:25.0)

Seem silly to require an email just to input a comment.

bmcpherson (posted 2009-08-19 19:05:55.0)

We used to buy this part with a shorter adjuster. I dont have any left but the adjuster would fit flush to the body. If I had to guess the old ones were 3/8" length but I am not entirely certain. An option for shorter adjuster screws to make the space occupied even smaller would be really nice.

Compact Kinematic Mirror Mount with Removable Knobs

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KMS(/M) Mechanical Drawing

Compact Profile: 1.00" x 1.13" x 1.30" (25.4 mm x 28.7 mm x 33.0 mm)
Angular Range: ±4°
Removable Knobs for Smooth, Long-Term Operation
Two 8-32 (M4) Tapped Holes for Vertical or Horizontal Post Mounting
(See Mechanical Drawing)
4-40 Tapped Hole on Front Plate for Attachment of Mirror Holder
(See Mechanical Drawing)

The KMS(/M) is a two-adjuster mirror mount with a compact design that occupies a 1.00" x 1.13" x 1.30" (25.4 mm x 28.7 mm x 33.0 mm) volume. The adjusters have removable knobs and are housed in bronze bushings to ensure smooth, long-term operation. In addition, the hex head on the adjusters allows a HKTS-5/64 hex key knob or 5/64" hex key to be used to make adjustments even when the knobs are removed.

The angular displacement range of the mirror face is ±4° with an adjustment per revolution of 15 mrad/rev. This mount has two 8-32 (M4) threaded holes that enable horizontal or vertical Ø1/2" post mounting. A 4-40 tapped hole on the front face plate of the mount allows our MH12, MH25, and MH25T Mirror Holders (available below) to be attached.

Low-Profile Compact Kinematic Mirror Mount

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Click for Details
KMSS(/M) Mechanical Drawing

Compact Profile: 1.00" x 1.13" x 0.79" (25.4 mm x 28.7 mm x 20.1 mm)
Angular Range: ±4°
Shortened Adjuster Screws for Reduced Footprint
Two 8-32 (M4) Tapped Holes for Vertical or Horizontal Post Mounting
(See Mechanical Drawing)
4-40 Tapped Hole on Front Plate for Attachment of Mirror Holder
(See Mechanical Drawing)

The adjusters of the KMSS(/M) mirror mount have been shortened to their minimum possible length in order to reduce the overall volume to 1.00" x 1.13" x 0.79" (25.4 mm x 28.7 mm x 20.1 mm). The length of the adjuster makes attaching a knob to the adjuster impossible, so a HKTS-5/64 hex key knob or 5/64" hex key must be used to adjust the mirror mount.

The angular displacement range of the mirror face is ±4° with an adjustment per revolution of 15 mrad/rev. This mount has two 8-32 (M4) threaded holes that enable horizontal or vertical mounting. A 4-40 tapped hole on the front face plate of the mount allows our MH12, MH25, and MH25T Mirror Holders (available below) to be attached.

We also offer the KMSR(/M) Compact Kinematic Mount for 1" rectangular optics.

Ø1/2" Mirror Holder

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MH12 with KMS and Ø1/2" Mirror

The MH12 Mirror Holder can be used to mount Ø1/2" (12 mm) mirrors. The optic slides into a double-bored hole and is held in place with a nylon-tipped setscrew that can accommodate mirrors that are at least 0.10" (2.5 mm) thick. On the back of the MH12 is a 4-40 threaded boss that screws into the front plate of the KMS(/M) and KMSS(/M) mounts.

Ø1" Mirror Holders

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MH25T with KMS and Ø1" Mirror

The MH25 and MH25T Mirror Holders are two-piece adapters that allow Ø1" mirrors to be mounted to the front plate of the Compact Kinematic Mounts featured on this page. Each holder features a 4-40 threaded boss that screws into the faceplate of the KMS(/M) or KMSS(/M) and comes with a retainer to secure the optic’s position within the holder. The MH25 mounts mirrors from 2.5 mm (0.10") to 6.1 mm (0.24") thick, while the MH25T mounts mirrors from 6.0 mm (0.23") to 10.0 mm (0.39") thick. The SPW909 spanner wrench can be used to easily separate the holder to mount the mirror.

Item #	Min. Optic Thickness	Max Optic Thickness
MH25	2.5 mm (0.10")	6.1 mm (0.24")
MH25T	6.0 mm (0.23")	10.0 mm (0.39")