---
title: "TN250212 - Stopping Shaft Rotation: Enhancing Precision & Efficiency"
description: Learn how to immobilize the shaft of your ORCA™ motor for precision applications such as label placement, automated welding, assembly lines, and press fitting components, with practical solutions and recommended components.
---

[Technical Notes ](https://irisdynamics.com/technical-notes)

# [TN250212 - Stopping Shaft Rotation: Enhancing Precision & Efficiency](https://irisdynamics.com/technical-notes/shaft-immobilization-techniques)

 Written by [Iris Dynamics](https://irisdynamics.com/technical-notes/author/iris-dynamics) | Feb 18, 2025 7:09:54 PM

 

Many applications using [ORCATM Series Smart Linear Motors](https://irisdynamics.com/products/orca-series) benefit from the ability to have a freely rotating shaft when an additional degree of freedom is required. Made from smooth stainless steel, the shaft ensures the motor is fully waterproof and IP68-rated, while maintaining its robust build. Unlike traditional linear actuators, the shaft can rotate freely, offering several benefits including reduced friction and wear, improved efficiency, increased precision, and design flexibility. For instance, in polishing or grinding tasks, a polishing disk may require a precise amount of force while simultaneously being powered by a separate drive motor. In such scenarios, a freely rotating shaft is ideal for this application.

There are instances where immobilizing the shaft from rotating during operation can be beneficial for your application. Some applications require an “end effector,” where the component attached to the end of the shaft remains stationary during operation. For example, when installing press-fit inserts, the motor is used to apply and monitor a specific amount of force and depth, but it may be undesired for the tooling die at the end to rotate. In such cases, preventing the shaft from rotating can be advantageous for achieving the desired result and ensuring precise control during the process.

This technical note will describe various ways you can immobilize the shaft from rotating.

 

## When to Immobilize the Shaft from Rotating

- If rotation alignment is critical for the application.
- If there are provisions and space available to attach the specified mechanism.
- If reduced shaft play is desired. 

 

## How to Immobilize the Shaft from Rotating

Mounting a Linear Bearing

There are several methods to use to stop the shaft from rotating. This example outlines a methodology requiring the least number of custom components. Required components are listed below:

- Flange-mounted linear bearings that fit 50mm spaced M4 screws.
- A rail that fits linear bearings with a satisfactory length for a full motor stroke.
- 4X M4 screws with a satisfactory length for a 5mm thread engagement in the stator.
- 1X M3 (or equivalent) screw to mount the rail to the end effector.
- End effector (or shaft mount) with threads for the rail screw – note that this must be rotationally locked to the shaft.

 

See the diagram above for this mounting option. The mount design features a through hole for the end of the shaft to allow additional components to be mounted on top of the component.

 

Practical Application Examples

|   | Packaging  | Manufacturing  | Press Fitting  |
| --- | --- | --- | --- |
| Application | Precision placement of labels or components. | Automated welding and assembly lines. | Press fitting components in precise orientations. |
| Benefit | Ensures consistent alignment which improves accuracy and efficiency in high-speed packaging lines. | A fixed orientation of the end effector improves the precision of welding and assembly processes, ensuring high-quality results and minimizing the need for rework. | Maintaining a fixed shaft orientation ensures components are press-fit correctly, improving assembly quality and consistency in manufacturing processes. |

## View More

Component Recommendations for Sample Designs 

See below the links for the various off-the-shelf components used:

- Horizontal Mount Linear Bearing: [View Here](https://www.mcmaster.com/6250K37/)
- Guide Rail: [View Here](https://www.mcmaster.com/6250K2/)
- M4X15 Socket Head Screw: [View Here](https://www.mcmaster.com/91290A306/)

Note: Ensure the components selected are rated for the loads and environments that the motor will experience. [Consult Iris Dynamics](https://irisdynamics.com/contact) for more application information if needed.

 

## End Effector Design

Always refer to the [Datasheet](https://irisdynamics.com/hubfs/Website/Downloads/Orca/Approved/Orca_Series_Datasheet.pdf) and [CAD models](https://irisdynamics.com/downloads) for the most up-to-date information on dimensions of the motors. The following resources are for reference only, and should be confirmed through [contacting a sales representative](https://irisdynamics.com/contact). Please note that Iris Dynamics does not provide the end effector. 

 

|   Critical Dimensions for Determining Mount Design |   **Critical Mount Features and Dimensions** |
| --- | --- |
|  |  |

The function of the component on the right is to add a properly positioned mounting thread for the rail, while being rotationally locked to the shaft. This can easily be combined into a design of a more comprehensive end-effector that might accomplish more functionality.

 

[View full post](https://irisdynamics.com/technical-notes/shaft-immobilization-techniques)

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