Machine Tool Calibration

API offers machine tool alignment, certification, calibration and certain repairs for machine shops and manufacturers. We provide our customers with confidence, knowing your machines are performing accurately and efficiently, which means good parts.

For nine years, our expert services team has calibrated hundreds of machine tools for customers around the world.  The industries and applications are varied with differing environments, accuracy requirements, space limitations and time constraints.  Many customers have their machines calibrated ever six months to one year, or after maintenance.

API are not only experts in standard “laser alignment,” so common throughout the industry.  We manufacturer our own laser equipment, so we know it works. We also provide volumetric compensations that ensure the best achievable accuracy throughout the machines entire workspace.  Our personnel not only have the laser alignment and calibration proficiency, we are also experts with the machine controllers.  API are solution partners for Siemens, Fanuc, Fagor and others.

This small investment can keep machines in service long beyond their expected lifecycle, providing substantial returns and the trust of your customer. API offers the most economical and efficient laser alignment solutions available.

Reasons to Error Map and Calibrate Your Machine

  • Reduce scrap, improve machine accuracy and keep your machine tool in specification
  • With a machine tool calibration from API, the machine will meet the intent of ASME B5.54
  • Reduce hours to mechanically align a machine. After an alignment or crash, the machine should always be calibrated
  • Required if you plan to measure a product on a machine
  • End customer requirement
  • Make full use of your Control’s capabilities. Often, we find many machines with empty compensation tables. Machine owners should utilize their Controller’s capabilities to increase machine accuracy and prevent unnecessary wear
  • Regular calibrations will help to recognize abnormal wear and tear so problems can be addressed and managed
  • Calibrate the kinematic parameters of the Tool Center Point (TCP) to enhance your machine
  • Accurate machines save money
  • Calibrations allow usage of the entire working volume of the machine, not just a “sweet spot” that you know is accurate within the volume
  • Increased capability, accurate machines allow you to take on more precise work that you may not have handled before a calibration

Laser Alignment for Machine Tools

Using laser alignment you can keep your machine tools in good working order by ensuring proper alignment. The value of this small investment cannot be overstated. Machine tools lacking proper alignment and pitch error compensation are not fully productive. Over time, these errors become magnified in faulty machine operation and substandard parts. API Services offers the most economical and efficient laser alignment solutions for your machine tool. API Services recommends a baseline reading of alignment for all service work and regular checks and adjustment as part of any ongoing preventive maintenance program. Recalibration, including a review of machine alignment, is also critical following any machine repair.

We’ll help you assure your customers that the products you produce will always meet their specifications. Our machine tool laser alignment service will help maximize the accuracy of your machine tool and certifies that products it produces meet the specifications you have specified in your set up.

Services and equipment for your machine tool alignment needs:

  • Laser Compensation
  • Laser Alignment
  • Ball Bar Analysis
  • Spindle Analysis
  • Machine Leveling
  • Machine Calibration
  • Machine Inspection
  • Baseline Analysis and Reporting
  • Digital Readouts (data and graphs)
  • Troubleshooting Problem Areas

Volumetric Machine Tool Calibration

Volumetric compensation is essentially an innovative method of assembling the volumetric map on a given machine. Up until now, a typical three-axis machine has used the traditional 21 error parameter method to measure machine-axis errors. Measurements were taken one at a time, along each individual axis, X, Y, and Z.

Each of the three axes has six error parameters: linear position, vertical and horizontal straightness, pitch, yaw, and roll. Each error parameter requires a different setup, and each required its own measurement process. In addition to these 18 error parameters, three more error parameters determine squareness of each of the X, Y, Z axes to each other, X to Y, Y to Z, and Z to X, for the total of 21 error parameters.  Even with the most sophisticated laser, this data acquisition is a long process, and roll in the Z axis must be determined by some other means. If the machine tool has additional axes, like a rotary axis, the calibration time increases rapidly.

Lastly, and in accordance with B5.54-2005, users can perform a diagonal displacement test that in theory measures the volume of the machine tool. This test is also time-consuming and is still not a robust indicator of the machine’s volumetric accuracy.


Depending on the machine type and control, API Services provides offers several volumetric machine tool methodologies:

API’s Volumetric Error Compensation (VEC)

API’s approach to the volumetric calibration solution consists of a precision laser tracker with interferometry capability. The interferometer feature of the laser tracker is the same technology traditional laser systems used for years to successfully calibrate machine tools. Coupling the interferometry technology with a laser tracker offers the added capability to track the machine’s tool-tip location through extensive axial movements throughout the entire volume of the machine.

Using the laser tracker and active target, the VEC method measures all 21 error parameters for 200–400 points within the machine’s working volume with all possible machine poses, even with the rotary axis. Each point becomes an accurate reflection of the machine’s kinematic errors. A complex algorithm is used to decouple error sources and build an extremely accurate volumetric map. Error compensation is done by adding the compensation from the entire measured axis to get the best tool-tip position.

Besides the measuring system, the API solution also includes a sophisticated proprietary calibration software that uses a polynomial equation-based, kinematic model of the machine to map errors throughout the volume. To compensate the machine in real time, the software resides on the machine’s controller or on an industrial computer that directly interfaces with the controller and machine tool.

In summary, the software uses the measurements from the laser tracker and active target and develops compensation values to drastically reduce machine errors. Once the machine is put back in production, the software runs in the background, monitors the programmed toolpath, and applies for real-time compensations automatically to the tool tip.  Typical machine improvements are 4 – 5

Siemens Volumetric Compensation System (VCS)

The Siemens Volumetric Compensation System (VCS) is suited to 3 – 5 axes machines running the SINUMERIK 840D Solution Line Control.  All measurement or calibration data is taken with our API XD Laser Measurement System and Software.  This process also produces significant reductions in volumetric positioning error. Siemens VCS factors all the machine kinematics of its various axes of motion, as well as pitch, yaw and roll, to precisely adjust the orientation of the tool tip to the workpiece.

Which is why Siemens’ Volumetric Compensation System (VCS) is an attractive solution. In addition to compensating for 21 possible linear errors in each machine, the Siemens system addresses rotary errors. With this capability, VCS not only compensates so that a cutting tool meets the material at the right place, it also ensures that the spindle is in the correct orientation.

Fanuc Volumetric Compensation (3DREC)

As a solution partner, API employs Fanuc’s CNC’s five-axis volumetric error compensation program, which increases machining accuracy by evaluating the tool location and orientation error throughout the machining volume.

Fagor Volumetric Compensation

The Fagor Volumetric Compensation (FVC) uses the API provided volumetric measurements to map the machine’s total work volume, ensuring the CNC understands the exact position of the tool tip. Benefits include a 50% improvement in accuracy, and machine-to-machine uniformed accuracy improvements.

Learn more about API’s Machine Tool Calibration & Repair Services

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