KT550-AC
XY Stages

High-load XY stage (ball screw) | Travel 250 x 250 mm | Rep ±0.3 µm, Load 81 kg, Speed 60 mm/s
KT550-AC

 

High-Load XY Stage with AC Servo Drive

The axes of the KT550 are driven by preloaded ball screws with AC servo motors. A specially optimized lubrication system ensures low-noise and speed-stable precision operation. The combination of profile rail guides, precision ball screws, and direct linear scale feedback provides high stiffness, excellent straightness, and defined flatness - ideal for demanding precision positioning and alignment processes.

  • Repeatability up to ± 0.3 µm
  • AC servo drive with ball screw (2 mm lead) for controlled dynamics up to 60 mm/s
  • High load capacity up to 81 kg and high moment load capability
  • Maintenance-free & reliable: used in the VLT (Very Large Telescope) of ESO

Options:

  • Measurement systems: linear scale or motor encoder, optional resolution up to 0.001 µm
  • Base plate made of granite or aluminum to further increase system stiffness
  • Preparation for air purge and enclosure
  • Brake, customer-specific adapters, and mounting hole patterns
  • Cleanroom versions up to ISO 6 (higher on request)
  • Radiation: UV (DUV, EUV, X-ray and Gamma on request)
  • Vacuum and low magnetic versions on request

References

XY Positioning systems for the Max Planck Institute for Extraterrestrial Physics used in the GRAVITY+ instrument of the VLT (Very Large Telescope) of ESO

Further links (external):
- GRAVITY and VLT at the Max Planck Institute for Extraterrestrial Physics
- GRAVITY+ Project at the Max Planck Institute for Extraterrestrial Physics

 

Application Fields

Precision positioning, precision assembly and alignment, optical metrology, sensor and camera positioning, semiconductor and wafer handling, laser processing, test benches, automation systems with high load capacity, research & development, structured scanning and inspection processes

 

KT550   -250-AC-L -250-AC-R
Travel [mm] 250 x 250 250 x 250
Repeatability, unidirectional [µm] ± 0.3 ± 0.9
Repeatability, bidirectional [µm] ± 0.4 ± 1.4
Positioning accuracy [µm] ± 2.3 ± 13.3
Flatness deviation [µm] ± 2.5 ± 2.5
Straightness deviation [µm] ± 1.3 ± 1.3
Positioning speed [mm/s] 40 40
Max. speed [mm/s] 60 60
Max. acceleration [m/s2] 0.6 0.6
Max. load Fx [N] 660 660
Max. load Fy [N] 660 660
Max. load Fz [N] 810 810
Max. load moment Mx [Nm] 25 25
Max. load moment My [Nm] 35 35
Max. load moment Mz [Nm] 45 45
Pitch [µrad] ± 45 ± 45
Yaw [µrad] ± 40 ± 40
Length [mm] 500 + motor overhang 125
Width [mm] 550 + motor overhang 75
Height [mm] 180
Weight [kg] 108
Ball screw type   Ball screw 1416/2.16.318.400 R P3P
Lead   2
Guide   Profile rail
Motor   AC servo
Feedback   Linear scale Motor encoder
Resolution of measuring system   0.1 µm standard, optional up to 0.001 µm / none
Material   Anodized aluminum
Optional features   Base plate (granite / aluminum), housing, provision for purge air, brake, custom adapters, hole patterns, cables / connectors
Cleanroom variants   up to cleanroom class ISO 6 (higher on request)
Beam variants   UV (DUV, EUV, X-ray, gamma on request)
Magnetism variants   magnetic
Vacuum variants   on request

 

Related Products


Your customized system

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Almost all atmospheric standard stages are unanodized with UHV lubrication for residual pressures up to 10-6 mbar and min. cleanroom class ISO 6 - or even better - available. Further stages for more demanding environments up to cleanroom class ISO 2, vacuum up to 10E-11 mbar or hard radiation you will find here:

Overview Clean Room & Vacuum XY Stages    Get in touch with our technical consultant

Materials for XY Stages

XY stages from Steinmeyer Mechatronik are predominantly manufactured from aluminum. This material provides an optimal balance of stiffness, weight, and thermal behavior—critical for high-precision two-axis positioning systems.

Aluminum efficiently dissipates localized heat. As a result, the system quickly reaches a thermally stable condition—an essential prerequisite for repeatable accuracy in XY applications, particularly in scanning or inspection processes.

The lower stiffness of aluminum compared to steel is compensated by design measures, for example through:

  • Optimized cross-sectional geometries of the X and Y beams
  • Reinforced base plates for larger travel ranges
  • Hollow profile constructions with high bending stiffness

For special requirements—such as magnetically sensitive or vacuum-compatible applications—steel or titanium versions are available as alternatives.


Functional Surfaces and Coatings for XY Stages

Depending on the operating environment, numerous customized surface and coating concepts are available in addition to standard finishes. These enable cleanroom compatibility up to ISO 1–2 (depending on application and process), as well as optimized properties for optically or chemically demanding environments.

For XY stages with high requirements regarding wear, friction behavior, or particle generation, we develop and qualify application-specific functional coatings, including:

  • Nickel coatings
  • PTFE & KEPLA® coatings
  • Fluorinated lubricants
  • Dicronite® / dry-film coatings
  • Application-specific coating combinations

The following surface options are also available:

  • Anodized (cleaned)
  • Alternative anodized colors
  • Aluminum bare, cleaned
  • Bilatal
  • Nickel

These surfaces are particularly suitable for:

  • High cleanliness requirements in cleanroom environments
  • Chemically aggressive environments (e.g., life sciences)
  • Optical systems with stray light requirements
  • Vacuum applications


Why Functional Coatings Are Critical for XY Stages (Before → After)

  • Standard surface → EUV-compatible surface
  • Reflective → Non-reflective, minimized stray light
  • Limited sliding performance → Optimized friction coefficients & reduced wear
  • Basic protection → Enhanced chemical & corrosion resistance
  • Standard configuration → Application-optimized performance

Special surface treatments are often required for UV / DUV / EUV applications (X-ray or gamma applications available upon request).

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XY stages are basically high-precision positioning systems that are used to move objects in two dimensions (X and Y axes). They are used in a variety of applications, such as microscopy, manufacturing and automation technology. The architecture of our motorized XY systems can be categorized into four basic concepts:

  • Stacked stages (“Ritter Sport architecture”)
  • Crossed linear stages (“cross architecture”)
  • Inverted pyramid (“cone architecture”)
  • Pyramid (“pyramid architecture”)

Most XY stages are built according to the principle of the plate stack, sometimes also called “Ritter Sport architecture”. They have a particularly compact, square design and meet the expectations of a cross table.

However, they move apart during operation and then take up more space in two dimensions around the travel distance. The overhanging of the massive plates leads to bending, which reduces accuracy. As the design rules require the guides to be longer than the lateral distance, there is unused material on the sides of the individual travel directions. This causes the stage itself to be comparatively heavy, but it provides no benefit and merely causes the cross stage to bend additionally during travel. This results in a strong positional dependency of the bending and thus of the precision.

The cross architecture is easy to implement and is created by bolting linear motion stages together in a criss-cross pattern. Movement in one direction takes place across the center footprint. Space must be reserved accordingly in this direction. The advantage is that the plates are less bulky, reducing overhangs and thus bending and the impact on precision. As there is no material spilling over the sides of the crossed individual stages, there is less warping. The space gained can be used for cable routing for the upper axis. This results in less warping depending on the position and thus in greater precision.

Microscope stages are usually constructed as an inverted pyramid, resembling a “sugar cone” in shape. Compared to other architectures, this is particularly compact, flat and light. The drives can easily be hidden under the overhanging plates, which is particularly advantageous for mobile devices. This architecture is sufficient for applications in which the load is always applied in the center, for example in hardness testing stages. However, as with the plate stack architecture, the plates move apart and then take up additional space in two dimensions around the travel range. This means that the inverse pyramid has disadvantages comparable to those of the plate stack architecture.

The fourth architecture is the strict pyramid structure, which is characterized by its large appearance and thus does not meet the usual expectations of an XY Stage. The advantage of this solution is that the plates do not move apart during operation, so that the stage always takes up the same space. The flat support of the lower plate on the base structure forms a very rigid base for the entire system. In addition, there is no unused or overhanging material on the sides. The guide carriages always run completely on rails supported by metal and the guidance ratio is always maintained. In this way, the pyramid architecture is characterized by excellent accuracy values and extremely low deviations during movement and under different loads.

The design of XY stages is primarily based on force requirements in X and Y directions, dynamics (acceleration / velocity), and the required positioning accuracy. Additional relevant factors include installation space, moving mass, thermal stability, and integration effort. Depending on the application, different drive concepts are used, identifiable by abbreviations in the respective product designation:

  • Ground ball screws or lead screws with SM motor (stepper motor), DC motor (brushed DC motor), or AC servo (AC servo motor)
  • Electrodynamic linear motors (ironless or iron-core) for highly dynamic XY scanning motion
  • Piezo motors such as Piezo-Legs® or Nanomotion® for fine adjustment or nanopositioning


Systematic Decision Structure for XY Stages

If priority is on … Recommended drive concept
Compact design & cost-efficient solution Stepper motor with screw drive
Dynamic motion & closed-loop control DC servo / BLDC with ball screw
Maximum dynamics & backlash-free direct drive Linear motor
Nanometer fine positioning & minimal footprint Piezo / Nanomotion / Ultrasonic

 

1. Stepper Motor in XY Stages

Typical Application

Compact XY positioning systems with moderate speeds and forces, for example in laboratory or alignment tasks.

Advantages

  • Cost-efficient
  • Simple integration
  • High holding torque at standstill

Disadvantages

  • Potential step loss under overload
  • Limited dynamics for high-speed scanning

Recommended for

  • Compact XY tables
  • Adjustment and positioning tasks
  • Laboratory automation
  • Vacuum-compatible applications with moderate dynamics

 

2. DC Servo or BLDC Motor in XY Stages

Typical Application

XY systems with closed-loop control for repeatable positioning and higher dynamic performance.

Advantages

  • Very smooth motion in both axes
  • High acceleration with moderate footprint
  • Precise position and velocity control

Disadvantages

  • Higher system cost
  • Requires servo drive and parameterization

Recommended for

  • High-speed XY scanning tables
  • Automated inspection systems
  • Synchronized multi-axis systems

 

3. Linear Motor in XY Stages

Typical Application

Direct drive for highly dynamic XY positioning systems without mechanical transmission.

Advantages

  • No backlash
  • Very high acceleration in X and Y
  • Ideal for continuous scanning processes

Disadvantages

  • Increased energy consumption
  • Thermal management required
  • Higher investment cost

Recommended for

  • High-dynamic XY scanning systems
  • Semiconductor inspection and metrology
  • Precision assembly with high cycle rates

 

4. Piezo, Nanomotion or Ultrasonic Drives in XY Stages

Typical Application

Nanometer-level fine positioning within an XY system or as a correction axis.

Advantages

  • Extremely fine step resolution
  • No magnetic fields
  • High holding force without power consumption

Disadvantages

  • Limited travel range
  • Low speed
  • Not designed for high continuous loads

Recommended for

  • Nanopositioning within XY systems
  • Optical fine adjustment
  • Active alignment applications
  • Magnetically sensitive or vacuum environments

Incremental scales made of steel or Zerodur® or Zeromet® are used as a feedback system in most cases. While this is sufficient for accuracy in the single-digit micrometer range, it makes sense to use interferometric position feedback for accuracy requirements below one micrometer. In systems with “open loop”, i.e. without a measuring system, only precision in the double-digit micrometer range can be achieved; however, due to the simpler controller and the lack of a measuring system, this is the more cost-effective solution.


Are you looking for a technical solution for your application?

Get your first 3D Design in a few days:

 

Katja Weißbach
Consulting

T +49 351 88585-64
E-Mail

Ronald Schulze
Consulting, Project Management & Engineering
T +49 351 88585-67
E-Mail

 

Francisco Samuel
Consulting &
Project Management
T +49 351 88585-85
E-Mail

 

Elger Matthes
Consulting, Concepts, Innovation & Engineering
T +49 351 88585-82
E-Mail

Our references