When load capacity, stiffness, and accuracy can not be compromised, structure preloaded slides are the clear winner. The large area under compensation in these massive structures provide for exceptional lift and preload. The result is high load capacity and stiffness. The design of this type of slide provides for full support of the moving elements in the entire travel of the stage. Professional Instruments Company makes two forms of structure preloaded slides; a fully surrounded shuttle, and the classic “H” frame slide.

In the fully surrounded version, the shuttle is contained inside the structural elements that make up the base. In Figure 1, a cross-section view of this type of slide is shown. Mounting of drive systems and process equipment is done on the ends of the structure or using the slot accessed from the top.

The “H” frame version of the structure preloaded slide is shown in Figure 2. The precision guide rails are supported on the base of the machine structure and the sliding elements fully envelop them. “H” frame slides provide the widest variety of mounting options for applying drive and feedback systems. The similarity in structure to our BLOCK-HEAD® spindles causes this type of slide to have our highest load capacity, stiffness, and accuracy. Square inches of area translates into load capacity. The large, stiff structures allow for tremendous preloads and high stiffness of the air films. The large mass involved in these types of structures make them ideal in machine tool applications.

The large elements used in these types of slides provide for considerable error averaging in the air bearing films, resulting in exceptional error motion properties. Typical Professional Instruments Company structure preloaded slides have straightness errors well under our normal one-millionth of an inch per inch specifications. The structural elements allow for additional features such as way covers, bellows, and limit switches to be easily accessed. Structure preloaded slides are yet another example of the advantages of contracting with Professional Instruments Company when precision motion systems are required. The fact that we build five different types of precision motion systems ensures that we will provide the slide that fulfills your requirements, as opposed to promoting what we happen to