> ## Documentation Index
> Fetch the complete documentation index at: https://docs.researchanddesire.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Standard Build Motor

> The 57AIM30 Gold Motor is the recommended motor for all new OSSM builds

The **57AIM30 Gold Motor** is the current standard motor for OSSM builds, offering the best combination of performance, size, and cost.

<Card title="Purchase Gold Motor" icon="cart-shopping" href="https://www.researchanddesire.com/products/ossm-motor-gold-motor">
  Available pre-programmed from Research and Desire, ready to use with your OSSM.
</Card>

## Why the Gold Motor?

The 57AIM30 replaced the legacy iHSV57 motor as the build standard due to significant improvements across all key metrics:

| Improvement                 | Benefit                                       |
| --------------------------- | --------------------------------------------- |
| 60% shorter                 | More compact builds, easier mounting          |
| 50% lighter                 | Reduced overall weight                        |
| 30% higher peak force       | Better performance under load                 |
| \~20% cheaper               | Lower build cost                              |
| Better over-torque handling | Configurable torque reduction vs hard disable |
| Drop-in replacement         | Compatible with existing NEMA23 hardware      |

## Sourcing Your Motor

### From Research and Desire (Recommended)

Motors from [Research and Desire](https://www.researchanddesire.com/products/ossm-motor-gold-motor) are:

* Pre-programmed for OSSM
* Tested and verified
* Ready to install

<Check>
  No additional programming required when purchasing from R\&D.
</Check>

### From Other Suppliers

If sourcing a generic 57AIM30, verify these specifications:

| Specification | Required Value |
| ------------- | -------------- |
| Speed rating  | 1500 RPM       |
| Interface     | RS485          |
| Model         | 57AIM30        |

<Warning>
  Do **not** purchase the 3000 RPM or CANBUS versions—these are incompatible with OSSM.
</Warning>

<Warning>
  **Avoid the 60AIM motor.** The 60AIM has a larger NEMA24 (60 mm) frame size that does not fit the standard OSSM printed parts, which are designed for NEMA23 (57 mm) motors. Using a 60AIM requires custom mounting hardware and modifications to the actuator housing.
</Warning>

<Note>
  Motors from third-party suppliers require programming before use. See the [programming guide](/ossm/Hardware/motor/programming) for instructions.
</Note>

## PCB Compatibility

The Gold Motor's improved efficiency generates more regenerative power during certain motion conditions, requiring additional capacitance on the PCB.

| PCB Version     | Compatibility                             |
| --------------- | ----------------------------------------- |
| V2.3 or newer   | Fully compatible, capacitor included      |
| V2.2            | Compatible with simple PH-4 cable wiring  |
| Older than V2.2 | Requires soldering wires to 10-pin header |

<Warning>
  If using a PCB older than V2.3, add a **1500µF capacitor (minimum 50V)** to handle regenerative braking. Without this capacitor, voltage spikes may damage your electronics.
</Warning>

## Technical Specifications

### Advantages

* **Compact size**: 40% of the length of the 180W standard motor
* **Lightweight**: 50% of the weight of the 180W motor
* **High performance**: 30% higher peak force in real-world testing
* **Configurable protection**: Reduces torque output instead of disabling on overload
* **Hardware compatible**: Same mounting pattern and shaft diameter as iHSV57

### Considerations

<AccordionGroup>
  <Accordion title="Regenerative power handling">
    The motor's efficiency means it generates more power during deceleration. PCB V2.3 includes the necessary capacitor; older boards require manual addition.
  </Accordion>

  <Accordion title="RS485 communication">
    The Gold Motor uses RS485 digital communication. This is handled by the OSSM PCB V2.2 and newer—no user configuration needed.
  </Accordion>

  <Accordion title="Software configuration">
    Default firmware settings work for most users. Advanced users can tune motor behavior through the programming tool, but incorrect settings may cause the motor to disable under torque.
  </Accordion>

  <Accordion title="Speed limits">
    The Gold Motor's maximum speed exceeds the OSSM software's default speed limit. Standard users won't notice any difference; only custom firmware modifications might encounter this limit.
  </Accordion>
</AccordionGroup>

## Motor Programming

<Info>
  Motors must be programmed to set steps per revolution to **800** for OSSM compatibility.
</Info>

* **R\&D motors**: Pre-programmed, no action needed
* **Third-party motors**: Require programming via USB to RS485 adapter

<Card title="Programming Guide" icon="code" href="/ossm/Hardware/motor/programming">
  Complete instructions for programming your motor with the web-based tool.
</Card>

## Software Compatibility

The OSSM firmware supports closed-loop servo motors and is tested with:

* 57AIM30 (Gold Motor) — **Recommended**
* 42AIM30 (Round Motor variant)
* iHSV57 (Legacy motor)

<Note>
  All supported motors use the NEMA23 form factor. Using stepper motors or other motor types requires custom hardware design and advanced firmware modifications.
</Note>

## Alternative Motors

<CardGroup cols={2}>
  <Card title="42AIM30 Round Motor" icon="circle" href="/ossm/Hardware/motor/alternatives/42AIM30">
    Compact variant with smaller diameter but limited mounting options.
  </Card>

  <Card title="iHSV57 Legacy Motor" icon="clock-rotate-left" href="/ossm/Hardware/motor/alternatives/iHSV57">
    Pre-2024 standard motor, still functional but no longer recommended for new builds.
  </Card>
</CardGroup>