# D57.1 UHV Stepper Motor

> 1.8°, two phase hybrid stepper motors (1 x 10-10 mBar)

Canonical product page: [https://arunmicro.com/products/D57-1_UHV_Compatible_Stepper_Motor/](https://arunmicro.com/products/D57-1_UHV_Compatible_Stepper_Motor/)

1,000 mNm, NEMA 23

## Product details

- Product code: `d57.1`
- Category: [UHV Stepper Motors](https://arunmicro.com/products/category/motors/)
- Made in the UK
- UK-based support

## Best for

High-torque ultra-high-vacuum motion applications requiring the greatest direct-drive torque available from AML's standard D-series UHV stepper motor range.

The D57.1 is a NEMA 23 UHV stepper motor with 1,000 mNm (1 Nm) holding torque.

Choose the D57.1 when the 550 mNm maximum torque of the D42 family is insufficient or where a larger NEMA 23 motor is appropriate for the mechanical design.

It is suitable for low-speed, precision in-vacuum positioning and manipulation of higher mechanical loads in UHV systems operating below 1 × 10⁻¹⁰ mbar.

## Not suitable when

Do not select the D57.1 solely because it has the highest holding torque in the range. Where lower torque is sufficient, a smaller D28, D35 or D42 motor may reduce size, mass and installation requirements.

Where more output torque, finer positioning resolution or improved inertia matching is required, consider combining the D57.1 with an AML PG57 UHV planetary gearhead.

Holding torque should not be treated as the available torque at all operating speeds. Review the required torque-speed operating point for dynamic applications.

The standard D57.1 is not suitable for operation below -65 °C; select the D57.1-C for operation down to -196 °C.

## Selection guidance

Select the D57.1 when up to 1,000 mNm holding torque is required and the larger NEMA 23 frame size can be accommodated.

The D57.1 provides the highest direct-drive holding torque in AML's standard D-series range.

For lower torque and a smaller motor, consider:
- D42.3: 550 mNm, NEMA 17
- D42.2: 450 mNm, NEMA 17
- D42.1: 250 mNm, NEMA 17
- D35.1: 75 mNm, NEMA 14
- D28.1: 55 mNm, NEMA 11

AML PG57 UHV planetary gearheads can be used where increased output torque, positioning resolution or inertia matching is required.

Motor selection should consider the required torque at operating speed, duty cycle, temperature, mechanical load and available installation space.

## Compatibility and prerequisites

The D57.1 is a two-phase bipolar hybrid stepper motor designed for installation inside an ultra-high-vacuum system.

A compatible bipolar stepper motor drive is required. AML SMD3 and SMD4 drives are designed for use with AML D-series vacuum stepper motors.

The embedded motor temperature sensor should be used for motor protection because convection cooling is absent in vacuum.

The D57.1 can be combined with AML PG57 UHV planetary gearheads where increased output torque, finer positioning resolution or inertia matching is required.

Confirm mounting, shaft coupling, axial and radial loads, available installation space, vacuum cabling and electrical feedthrough requirements before ordering.

## Ordering guidance

Standard order code: D57.1 — 1,000 mNm UHV stepper motor.

Available configurations include:
- D57.1-C — cryogenic version, -196 °C to +190 °C
- D57.1-H — dry-lubricated hybrid ceramic bearings
- D57.1-P — PT100 temperature sensor instead of the standard thermocouple
- D57.1-R — gamma-radiation-hardened version, rated to 1 × 10⁶ Gy
- D57.1-X — custom shaft modification

Before requesting a quotation, provide the required quantity and identify any cryogenic, bearing, radiation, temperature-sensor, shaft, connector, cabling or gearhead requirements.

If motor suitability is uncertain, provide operating pressure, temperature range, required torque, operating speed, duty cycle, mechanical load and mechanical interface.

## Order codes

| Order code | Description | Price |
| --- | --- | --- |
| D57.1 | 1,000 mNm UHV stepper motor | £1,176.00 |
| D57.1-C | D57.1, Cryogenic -196 °C to +190 °C | £1,269.00 |
| D57.1-H | D57.1, Dry lubricated hybrid ceramic bearings | £1,269.00 |
| D57.1-P | D57.1 with PT100 temperature sensor in lieu of thermocouple | £1,235.00 |
| D57.1-R | D57.1, Gamma radiation hardened | £1,269.00 |
| D57.1-X | D57.1 with shaft modification | Price on request. Contact AML for a quotation. |

## Overview

- Suitable for use below 1 x 10-10 mBar (7.5 x 10-11 Torr)

- Continuous running in vacuum at high torque and step rates with AML drive

- Bakeable to 200 °C

- Step angle of 1.8°

- Step angle tolerance of ±5%

- Operational temperature range -65 °C to +190 °C

- Embedded thermocouple or PT100 sensor

- Open construction with all internal spaces vented

- Cryogenic extended operating temperature option available, range -196 °C to +190 °C

- Gamma radiation hard versions available 1 x 106 Gy

- Standard motors are fitted with open stainless steel bearings, lubricated with NyeTorr® 6300 ultra low outgassing UHV grease 

- Custom shaft modifications available

## Documentation and downloads

- [Application of UHV Stepper Motors](https://arunmicro.com/documentation/APN_Application_Notes_for_UHV_Stepper_Motors.pdf)
- [Axial & Radial Loads](https://bookstack.vps-da8d40f3.arunmicro.com/books/axial-and-radial-loads-on-aml-stepper-motor-bearings)
- [Datasheet](https://arunmicro.com/documentation/Datasheet_AML_UHV_Compatible_Stepper_Motor.pdf)
- [Magnetic Leakage Fields](https://arunmicro.com/documentation/APN_Magnetic_Leakage_Fields.pdf)
- [Material Content](https://arunmicro.com/documentation/APN_Material_Content_of_AML_UHV_Stepper_Motors.pdf)
- [Operating Instructions](https://bookstack.vps-da8d40f3.arunmicro.com/books/d-series-uhv-stepper-motor-user-manual)
- [RoHS](https://arunmicro.com/documentation/CE_AML_UHV_Stepper_Motors.pdf)
- [Vacuum Performance](https://arunmicro.com/documentation/APN_Vacuum_Performance_of_AML_UHV_Stepper_Motors.pdf)
- [CAD Models (.STEP)](https://arunmicro.com/downloads/CAD_VCSM.zip)

## Related products

- [D42.3 UHV Stepper Motor](https://arunmicro.com/products/D42-3_UHV_Compatible_Stepper_Motor/): 550 mNm, NEMA 17
- [SMD4 Stepper Motor Drive](https://arunmicro.com/products/smd4-stepper-motor-drive/): Stepper motor drive optimised for use with AML UHV-compatible motors. Features advanced connectivity with USB, Ethernet and RS232/485 interfaces. Optional encoder module for incremental and absolute encoders
- [SMD3 Stepper Motor Drive](https://arunmicro.com/products/smd3-stepper-motor-drive/): Stepper motor drive optimised for use with AML UHV-compatible motors. Four operating modes including USB remote from a host PC and opto-isolated step and direction inputs. Continuous monitoring of motor temperature is provided with automatic shutdown to prevent motor damage.
- [UHV Stepper Motor Gearheads](https://arunmicro.com/products/stepper-motor-gearheads/): UHV planetary gearheads for use with AML stepper motors to increase step resolution and torque.
- [MLF18F](https://arunmicro.com/products/electrical-feedthrough/): MLF18F 18-way feedthrough on a DN40 CF flange (70 mm OD). Individual glass compression seals and bakeable to 250°C.
- [MLF18 UHV Connectors](https://arunmicro.com/products/vacuum-side-connector/): UHV, 18-way Vacuum-Side Connectors.
- [VCC7 UHV Connectors](https://arunmicro.com/products/vcc7-vacuum-side-connectors/): UHV, 7-Way Vacuum Compatible Connectors.