Custom 4-Axis UHV Mechanism with VSM17 Stages

Posted on Monday 13th June 2022 at 11:42


Arun Microelectronics Ltd is proud to share our latest custom UHV mechanism that uses our new range of VSM17 UHV modular stages. With standardised mounting patterns and adapters, this mechanism highlights how VSM17 stages can be used to create complex multi-axis positioning systems, reducing the need for custom parts.


Vacuum: 1E-7 mBar

Temperature: 0 °C → + 70 °C

Load: 6 kg centred on rotary table



The mechanism features the following AML products for each axis:


Custom 4-axis mechanism


The XYZ axes feature the SG35-005, AML's new UHV gearhead. The UHV inline spur gearhead couples directly with AML's D35.1 stepper motor to increase resolution and achieve torque multiplication. With this option included, the XYZ axes achieve a full step resolution of 1 µm. The SG35 UHV inline spur gearhead is available as an option for VSM17-X stages and also as a separate product for use with D35.1 UHV-compatible Stepper Motors. Read more about the SG35 UHV inline spur gearhead here:


Every axis of this mechanism is fitted with Renishaw UHV compatible incremental encoders. These enable the user to receive positional feedback while controlling the mechanism.

The mechanism was designed in collaboration with our customer to meet their requirements, ensuring that it can support a 6 kg centred load on the rotation stage. The VSM17 stages' use of crossed roller bearings enables the stages to have high rigidity and high load capacity. The rotation stage also features a counterweight to meet our customer's backlash requirements.

This mechanism was constructed and assembled using only UHV-compatible methods and materials. It was built and extensively tested in our ISO class 7 cleanroom, ensuring its quality, performance and UHV-compatibility. At each stage of construction, extensive testing was carried out. Read more about the testing performed on our UHV Stepper Motors here:

Listed below is the finalised specification of the mechanism:

Axis X Y Z R
Motor type D35.1 D35.1 D35.1 D35.1
Gearhead SG35-005 SG35-005 SG35-005 -
Stacking order 1 2 3 4
Lubrication Nyetorr® 6300 Nyetorr® 6300 Nyetorr® 6300 Nyetorr® 6300
Guide type Crossed roller Crossed roller Crossed roller Crossed roller
Load (kg) - - - 6
Travel (deg/mm) 150 mm 150 mm 200 mm 90°
Resolution (per step) 1 μm 1 μm 1 µm 0.005°
Max speed (Hz) 2000 2000 2000 2000

NyeTorr® ultra-low outgassing grease was used on the motor bearings, leadscrews, worms and gears. This helps ensure the operational longevity of the mechanism.

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