Custom 7-Axis UHV Mechanism

Posted on Monday 16th January 2023 at 16:00

Arun Microelectronics Ltd is proud to share our latest custom UHV mechanism. This complex 7-Axis system features multiple custom stages designed specifically to meet the unique requirements of its application. Watch our video demonstration of this mechanism above.

Vacuum: 1x10-8 mBar
7-Axes of movement
Multiple custom stages
Independent 600 mm length detector arm


Custom Stages:



Custom Coaxial Rotation 1 and Detector Arm: The detector arm is able to rotate independently from the rest of the system, as shown in the video above. This independent rotation allows for a greater range of motion and positioning options, making it a versatile and valuable feature.

The ability to rotate independently adds an extra layer flexibility to the system that increases its capability for a wide range of applications and environments.


Custom Coaxial Rotation 2: The second custom rotation stage provides a rotational axis for the main body of the mechanism, including the following axes: X, Y, Z2 and R3. This rotation stage is independent of R1, which enables the sample mounted on R3 to be positioned independently of the detector arm, increasing the variety of configurations this mechanism can achieve.


Modified VSM17-X-100-LS Wide Body: This custom design is adapted from AML's standard VSM17-X-100. It features a unique wide-body design to fulfil the load and stability requirements of the application.


Modified VSM17-X-350-HR-LS: To maximise the length of motion available, a custom VSM17-X-350 was designed with an extended travel of 350 mm. This stage features AML's SG35-005 UHV spur gearbox to increase the resolution to 1 µm. This high resolution is essential to achieve precise positioning of the sample.

7-Axis Mechanism



Custom Rotation 3: Custom rotation stage featuring AML's D42.2 stepper motor, PG42 planetary gearbox and limit switches. This stage also features custom bevel gearing which in conjunction with the 50:1 ratio planetary gearhead, enables R3 to achieve a high resolution of 0.001° per full step.

7-Axis Mechanism




This UHV mechanism is designed to offer precise motion control across seven degrees of freedom to maximise the variety of positioning options of the system. R3 is designed to support a sample of up to 20 kg. Once mounted, the sample can be manipulated and positioned across five degrees of freedom. The detector is mounted on the Z1 axis which can be vertically manipulated on the standard VSM17-100-HR-LS and rotated around the centre of the mechanism by the independent coaxial rotation stage. The independent coaxial rotation stage can travel 0-355° around the mechanism to maximise the detector's coverage of the sample. Using AML's SMD3 and Device Control Software, all seven axes can be manipulated simultaneously which enables each axis to rapidly orientate to precisely configured positions.

All stages are equipped with AML's UHV-compatible limit switches to improve the degree of control for each axis. Limit switches can be connected directly to AML's SMD3 stepper motor driver and utilise the SMD3 "Home" mode. This mode drives the axis to the positive or negative limit switch, allowing positions to be conveniently reset. This can then be used as a repeatable zero-position when writing scripts.

Aside from the Z1 axis, each axis is wired through the D-sub connection hub. This features UHV-compatible D-sub connectors to simplify the mechanism's connections, whilst maintaining UHV compatibility.

This mechanism was constructed and assembled using UHV materials and methods. These include the use of AML's UHV-compatible motors that feature vent holes and polyimide enamelled windings. All leadouts are polyimide wrapped, with limit switches and connectors manufactured in UHV-compatible PEEK. NyeTorr® ultra-low outgassing grease was used on the motor bearings, leadscrews, worms and gears. This helps ensure the operational longevity of the mechanism. Assembly and testing of the mechanism was completed in our ISO Class 7 cleanroom.


7-Axis Mechanism


This mechanism was driven by AML's SMD3 stepper motor drives and a script created in our AML Device Control Software.


Listed below is the full specification of this mechanism:

Motor Type D35.1 D42.2 D42.1 D35.1 D35.1 D42.2 D42.2
Stacking Order 7 6 5 4 3 2 1
Lubrication Nyetorr® 6300 Nyetorr® 6300 Nyetorr® 6300 Nyetorr® 6300 Nyetorr® 6300 Nyetorr® 6300 Nyetorr® 6300
Guide Type Crossed roller Crossed roller Crossed roller Crossed roller Crossed roller Crossed roller Crossed roller
Load 5 20 20 - - - -
Travel 100 mm 0 - 360° 50 mm 350 mm 100 mm 0 - 355° 0 - 355°
Resolution (per step) 1 µm 0.001° 1 µm 1 µm 5 µm 0.001° 0.001°
Max Speed 5 mm/s 2 °/s 5 mm/s 5 mm/s 5 mm/s 2 °/s 2 °/s


If you would like to discuss your in-vacuum motion system requirements, please do not hesitate to contact our dedicated team by emailing