Introduction: Travel tells you how far an XY stage can move, while platform size describes its mounting envelope, and both affect how a laboratory layout will work.
When engineers compare an electric XY translation stage, two dimensions often attract attention first: travel and platform size. They are related to the physical space available in a system, but they answer different questions. Travel describes movement along the X and Y axes. Platform size describes the surface that carries a microscope sample, optical component, fixture, or other equipment. Reading the two numbers together gives a useful starting point for layout planning, but a complete installation view also depends on outer dimensions, holes, clearances, and the geometry of the equipment being mounted.
Travel is the distance through which a stage can move along an axis. For an XY stage, the listed travel normally applies to both the X axis and the Y axis. A specification of 100 mm X/Y travel therefore describes movement in two perpendicular directions, rather than a single 100 mm movement that combines both axes. This distinction matters when planning a sample scan, microscope positioning task, or optical measurement path. The stage creates a two-dimensional movement range, with the actual position controlled by moving one axis, the other axis, or both in sequence. The LDTDP-JG Series Motorized XY Stage provides three clearly separated travel options. The LDTDP-50-JG-2 lists 50 mm of X/Y travel. The LDTDP-100-JG-2 lists 100 mm of X/Y travel. The LDTDP-170-JG-2 lists 170 mm of X/Y travel. These figures describe the movement range associated with each named model, so they should remain tied to the model numbers when specifications are discussed. A reader comparing a 50 mm travel electric XY stage with a 170 mm version is comparing the available axis movement, not automatically comparing two mounting surfaces of the same size. The practical meaning of travel depends on the task. A microscope sample may need a modest movement range to bring different areas of one specimen under the objective. An optical component may need a larger range to align with several fixed beam positions. An automated measurement system may require enough movement to reach multiple inspection points without manually repositioning the equipment. In each case, travel describes the range of motion the stage can provide. The required range comes from the distance between the positions that the payload must reach, including the setup position and any access margin used during operation. Motion specifications are commonly separated into travel, speed, resolution, and repeatability because each describes a different part of stage behavior. For this guide, the important point is that travel is a spatial range. It is measured along an axis and is used to understand where the moving platform can go. General XY-stage specifications from MKS also treat axis movement and platform dimensions as separate parts of stage selection, which helps explain why a single number cannot describe the whole installation.
Platform size describes the physical envelope of the stage surface used to support or attach a payload. The LDTDP-50-JG-2 lists a 150 x 150 mm platform. The LDTDP-100-JG-2 lists a 300 x 300 mm platform, and the LDTDP-170-JG-2 also lists a 300 x 300 mm platform. These figures make an important point: a longer travel range does not automatically require a larger listed platform, and a larger platform does not automatically provide a longer travel range. A 300 x 300 mm platform can support a broader mounting layout than a 150 x 150 mm platform in terms of its stated surface envelope. That may be useful when an optical fixture has a wide footprint or when several attachment points need to sit on the moving surface. However, the platform dimension is not the same thing as the stage's travel. The LDTDP-100-JG-2 combines 100 mm X/Y travel with a 300 x 300 mm platform, while the LDTDP-170-JG-2 combines 170 mm X/Y travel with the same listed platform size. The platform envelope remains the same in the published figures even though the travel changes. A useful way to read these specifications is to imagine two separate drawings. The first drawing shows the movement envelope: how far the moving surface can shift in X and Y. The second drawing shows the platform envelope: the stated length and width of the surface carrying the payload. The two drawings overlap in a real stage, but they answer different layout questions. Travel helps determine reach. Platform size helps determine the footprint available for mounting. Neither one alone describes every part of the physical system. Laboratory layout example: Imagine a microscope sample fixture placed on an XY stage. The travel determines how far the sample can be repositioned under the microscope objective. The platform size affects whether the fixture can sit on the moving surface in a stable, practical arrangement. A larger fixture may fit within the listed platform envelope but still require a particular hole pattern, edge clearance, or adapter. A smaller fixture may fit physically while leaving too little room for cables or surrounding hardware. These are layout questions, not conclusions that can be made from travel alone. Dimensional language also deserves attention. A value such as 150 x 150 mm usually communicates two orthogonal platform dimensions, while 300 x 300 mm communicates a larger square envelope. It does not describe thickness, the full stage body, the distance between mounting holes, or the area that remains accessible after a fixture is installed. Dimensional metrology work, including the material published by NIST, relies on clearly defined measurement features and reference conditions. In practical stage planning, the same habit helps: identify what each dimension measures before using it to judge physical fit.
Travel and platform size become useful only when they are connected to the geometry of the complete setup. A stage can offer enough axis travel for a microscope sample while still requiring a mounting arrangement that changes the effective workspace. Likewise, a platform can appear large enough for an optical component while the component's base, adapter, cable path, or surrounding hardware occupies part of the available area. The listed values provide the movement and surface starting points; the installation drawing turns them into a layout judgment. The three LDTDP-JG models create three distinct specification combinations. The LDTDP-50-JG-2 pairs 50 mm X/Y travel with a 150 x 150 mm platform. The LDTDP-100-JG-2 pairs 100 mm X/Y travel with a 300 x 300 mm platform. The LDTDP-170-JG-2 pairs 170 mm X/Y travel with a 300 x 300 mm platform. This arrangement allows a reader to separate two decisions: how much movement the task needs and how much stated platform envelope the payload arrangement calls for. It also shows why the 100 mm and 170 mm models should not be described as having different platform sizes simply because their travel values differ. For a microscope sample, the key spatial question is often the distance between the areas that must be brought under the objective. For an optical component, the question may be the distance between alignment points or measurement positions. In both examples, the payload geometry affects the result. A long fixture may extend beyond the platform envelope even when its mounting base appears narrow. A tall component may need clearance beneath or above adjacent equipment. A cable loop may occupy space that is physically present but unavailable during motion. These relationships are part of the installation drawing. The following distinctions help turn the published dimensions into a more realistic spatial picture:
This is why a 100 mm travel specification cannot be converted into a guaranteed 100 mm usable mounting area. Travel describes movement along the axes. A usable mounting area depends on the platform surface, attachment pattern, payload shape, clearance, and the surrounding system. The same principle applies to the 150 x 150 mm and 300 x 300 mm platform figures: they are important spatial references, but they are not complete installation drawings. For a real system layout, engineers should connect the stage dimensions to a scaled drawing of the microscope, sample holder, optical component, or measurement fixture. The drawing should show the starting position, required motion range, fixed obstacles, cable path, tool access, and the space occupied by adapters. Because complete outer dimensions, mounting holes, clearances, and usable workspace are not established for these models, compatibility conclusions should wait for the relevant dimensional information.
XY stage travel and platform size describe two different parts of the same motion system. The LDTDP-50-JG-2 lists 50 mm X/Y travel with a 150 x 150 mm platform, while the LDTDP-100-JG-2 and LDTDP-170-JG-2 list 100 mm and 170 mm X/Y travel with 300 x 300 mm platforms. Travel explains reach; platform size explains the stated mounting envelope. For microscope positioning, optical components, and automated measurement layouts, the final spatial judgment also requires outer dimensions, mounting holes, clearances, and payload geometry. Reviewing those dimensions alongside the model-specific figures gives engineers a clearer basis for selecting and integrating an XY stage.
Q：What does travel mean on an XY stage?
A：Travel is the distance an XY stage can move along its X axis and Y axis. A stage listed with 100 mm X/Y travel provides a 100 mm travel specification for each axis, creating two-directional positioning movement. The required value depends on the distance between the sample, optical component, or measurement points that the system must reach.
Q：What is the difference between stage travel and platform size?
A：Stage travel describes how far the moving mechanism can shift along the axes. Platform size describes the stated length and width of the surface that carries the payload. For example, the LDTDP-100-JG-2 lists 100 mm X/Y travel and a 300 x 300 mm platform. These figures describe movement range and mounting envelope, respectively.
Q：Do 100 mm of XY travel guarantee a 100 mm usable mounting area?
A：No. A 100 mm X/Y travel value describes axis movement, not the size of the usable mounting surface. Practical mounting space depends on the platform dimensions, hole pattern, edge clearance, payload shape, cable path, and surrounding equipment. The LDTDP-100-JG-2 lists a 300 x 300 mm platform, while the exact usable workspace requires the corresponding installation dimensions.
MKS Inc. XY Translation Stages
