SchneebergerMMS-2XLinear Scale Read Head for Integrated Magnetoresistive Measuring System — Size 35 Rail, Read Head Only (No Rail, Scale, Cable or Electronics)

Product Description

What this part is

A Schneeberger linear scale read head for the MMS-2X integrated length-measuring system. Schneeberger builds its measuring systems into the profile rail of a linear guideway: the scale is a series of magnetised north and south poles at a constant pitch, integrated directly into the rail so it is protected from contamination and geometrically aligned with the guide point by construction. This part is the sensing head that rides over that scale and converts its position into an electrical signal.

Correcting the source data — this is not a limit switch:
Our previous title and description called this a “limit switch” with a “snap action mechanism.” That is wrong, and it is worth being blunt about because it would send this part to entirely the wrong buyer. There is no snap action, no contact set, no actuator lever and no mechanical switching element in it. It is a magnetoresistive scale reader head — a precision position-measurement sensor. Independent CNC parts dealers catalogue MMS-2X / LIM-2X-35 explicitly as a Schneeberger linear scale reader head, and the LIM part-number family is Schneeberger’s read-head designation, not a switch designation.

The likely origin of the error is the letters “LIM,” which read as an abbreviation of “limit” to anyone entering the part quickly. In Schneeberger’s scheme it identifies the linear measuring head. We have corrected the title, the short description and the product category accordingly.

Decoding the order code

MMS-2X — the Schneeberger integrated measuring system family this head belongs to.LIM — linear measuring (read) head.2X — the measuring-system generation, matching the MMS-2X designation.35 — the rail size. This is the critical field: it is the size of the Schneeberger profile rail the head is built to sit over. A size 35 head does not fit a size 25 or size 45 rail, because the head geometry and the scale position are rail-size specific.S — variant designation. The closely related SI variant (LIM-2X-35-SI, catalogued against Schneeberger reference 580100839) also appears in the market. We could not find a published decoder distinguishing S from SI, so we are not asserting one and we are not asserting they are interchangeable. Match the exact suffix against your machine’s parts list.

Why an integrated rail-scale system changes the buying question:
On a conventional machine, the linear encoder is a separate glass or steel scale bolted alongside the guideway. The guide point and the measuring point are then in two different places, and any deflection, thermal growth or mounting error between them shows up as a position error at the tool. Schneeberger’s approach puts the scale inside the rail itself, so the guide point and the measuring point are one and the same and stay aligned by construction.

The practical consequence for a buyer of this head: it is not a general-purpose encoder. It only works on a Schneeberger rail carrying the matching MMS-2X scale. If your machine has a Schneeberger MONORAIL or MINIRAIL axis with an integrated measuring system and the head has failed, this is the part that restores the axis. If you are trying to add position feedback to a plain rail, this head cannot do it — you would need the measuring-system rail as well, which is a much larger purchase.

What is not included

The read head only. Not included, and each is a separate item: the profile rail with its integrated magnetised scale, the guideway carriage or runner block, the mating connector and cable assembly, any interface or signal-conditioning electronics, and the mounting shims or alignment fixtures. Note that read-head-to-scale ride height and lateral alignment are specified tolerances on a magnetoresistive system — fitting the head is a set-up operation with a gap specification, not a bolt-on, and Schneeberger’s own installation instructions for the measuring system are the authority for the numbers.

Interchange guidance

Search forms include MMS-2X, MMS2X, MMS 2X, LIM-2X-35-S, LIM2X35S, LIM 2X 35 S, LIM-2X-35 and Schneeberger 580100839. Related and adjacent Schneeberger measuring systems: AMSA (analogue signal interface), AMSD (digital interface), AMSABS and AMSABS 3L (absolute magnetoresistive, no reference run required, 3L for long multi-rail axes), and MINISCALE PLUS on MINIRAIL miniature guideways. The MMS-2X is the earlier generation; AMSA and AMSD are the current-production incremental systems and AMSABS the current absolute system. They are functionally the successors but they are not drop-in replacements for an MMS-2X head — the scale in the rail is part of the system, so migrating means changing the rail.

That single fact is why an original MMS-2X head is worth buying rather than upgrading: replacing the measuring system means replacing the guideway, which on most machines means stripping the axis.