Introduction to Manipulators

The VG Scienta range of manipulator equipment is designed to be modular. The individual modules such as the translator, rotary drive and sample holder are compatible to allow complex applications to be built up from a range of simple units.

Checklists are included with each translator to take you through the configuration process in which you choose the modules that, when combined, give the manipulator best suited to your individual application. An example of a typical configuration is shown with each checklist.

To order a manipulator, VG Scienta will request a more detailed Ordering Questionnaire which confirms the chosen configuration. This is normally completed by one of our agents, but a copy can be supplied on request.

Use the Selection chart on Page 5-06 to choose the most suitable translator or manipulator for your application. e.g. HPT Transax Omniax
Choose the required modules and accessories. e.g. Z Slide XY Stage Rotary Module Motors Sample Holder Sample Services
Complete the checklist for the chosen translator.
Contact Vacuum Generators or your local VG agent with any queries and for completion of the Ordering Questionnaire.

Terminology

Manipulator. This is a combined translator, sample holder and rotary module, connected to the vacuum chamber and used for sample manipulation. Module. Where an assembly can be built up from sub-assemblies that vary to suit the application, the sub-assemblies are described as modules. Modules can often be used separately or in other assemblies, for example rotary drives or sample holders. VG Scienta modules are designed to be suitable for the widest possible range of applications. Translator. This is the module that provides X, Y and Z motions and which mounts to the vacuum vessel. This is sometimes referred to as a manipulator if no additional modules are fitted to it. Single bellows translators. These use the same bellows to give X, Y and Z movements. They are simple and easy to use in any orientation. Feedthroughs for example are attached to the base flange.

Double bellows translators. These have separate bellows for the Z movement and for the the XY movement, with the benefits of the increased sample stability and greater range of movement. Feedthroughs for sample services are attached to the travelling flange.

Z Slide. This is the part of the translator which provides the Z movement. The Z axis refers to the manipulator and is independent of the mounting orientation of the manipulator.

XY Stage. This is the part of the translator which provides the X and Y movement. The XY stage used on double bellows translators cab be adapted for use as a separate item (i.e. XY table).

Vectorial Sum. The XY movement is restricted by the total vectorial displacement or offset from the central position. For example, if the vectorial limitation is ±12.5 mm and X = 8 mm, then Y max is given by:

Y² = 12.5² - X²

So Y = ±9.6 mm maximum

R1 rotation. Referred to as primary axis or polar axis rotation. This is rotation about the axis of the Travelling Flange.

R2 rotation. Referred to as azimuthal rotation, where the axis of the rotation is normal to the sample surface.

R3 rotation. Referred to as sample tilt or flip, where the axis of rotation is parallel to the sample surface.

Secondary movement. Where a drive is used to provide a movement in addition to the primary rotation, this is referred to as secondary movement.

Translator Tilt. This is the ability to tilt the Rotary Drive, an option only available on HPT translators. This option is often used to achieve additional X or Y travel.

(Bellows) Support Tube. These are fitted within the bellows and along the Z-axis of double bellows translators. They are used for protection of the bellows, securing the sample service wiring and improvement of the sample stability. Where differentially pumped rotary feedthroughs (DPRF's) are used, the support tube can be made to rotate.

Clear bore. This refers to the bore of the translator, excluding the travelling flange, when the XY stage is in the central position. The clear bore of single bellows translators reduces as the X and Y movements are offset. See also "Probe size".

Probe. This is an object, such as a rotary drive, fitted long the Z axis of the manipulator. The maximum probe diameter is limited by the bellows or flange bore, and by the XY offset. Wider probes can be fitted, but the XY movement will be restricted on single bellows translators. Where a support tube is fitted, the probe size does not affect the XY stage movement.

Bolt pattern. Flange bolt holes can be straddled, in-line or universally aligned to a given axis. In most cases, alternative types can be provided.

Sample holder. These attach to rotary drives to provide mounting for sample services such as heating, cooling or thermocouples and may include a mechanism for secondary rotation of the sample. Various styles are available, offering different rotation options. The sample itself is usually attached to the sample plate of the service accessory rather than the sample holder itself. All models have an offset adjustment to allow for variations in sample thickness.