In the world of precision automation, converting rotary motion into linear motion is a fundamental challenge. While traditional systems use belts, pulleys, or external couplings, Linear Stepper Motors (also known as Hybrid Linear Actuators) offer a superior alternative. By integrating a threaded lead screw directly into the motor rotor, these actuators provide a compact, rigid, and highly accurate solution.
At AKT Motor, we offer a comprehensive range of Hybrid Linear Stepper Motors (HSL Series). But with options ranging from the miniature NEMA 8 to the robust NEMA 23, how do you select the right one for your application?
This guide will walk you through the four critical steps to specifying the perfect linear actuator.
Step 1: Determine the Force and Frame Size
The first and most important factor is the thrust force required to move your load. Generally, a larger motor frame size correlates with higher holding torque and thrust capabilities.
- For Miniature Precision (NEMA 8 / 20mm): If your application is space-constrained—such as handheld medical analyzers or portable optical devices—the 20HSL Series is your best choice. It offers incredible precision in a tiny 20x20mm package.
- For Compact Power (NEMA 11 / 28mm): The 28HSL Series strikes a balance between size and power. It is widely used in syringe pumps and laboratory sample movers where slightly more force is needed than a NEMA 8 can provide.
- The Industry Standard (NEMA 17 / 42mm): The 42HSL Series is the “workhorse” of the 3D printing and desktop CNC industry. It offers high torque (up to 0.75 N.m) and is versatile enough for most Z-axis lifting and XY stage applications.
- For Heavy-Duty Loads (NEMA 23 / 57mm): When moving heavy gantries or driving industrial packaging machinery, you need the 57HSL Series. With holding torques reaching 2.0 N.m, this motor handles demanding loads with ease.
Step 2: Balance Speed vs. Resolution (Choosing the Lead)
Once you’ve selected the motor size, you must choose the Lead Screw specifications. The “Lead” is the distance the nut travels in one full revolution of the screw.
- High Resolution & High Thrust: Choose a smaller lead (e.g., Tr3.5 x 0.61mm or Tr5 x 1mm). This provides finer positioning steps and multiplies the motor’s torque, making it ideal for vertical lifting where you don’t want the load to drop (self-locking effect).
- High Speed: Choose a larger lead (e.g., Tr8 x 8mm). This allows the load to travel a longer distance per step, enabling faster movement speeds, though at the cost of some mechanical advantage.
Step 3: Define the Stroke Length (Customization)
One of the biggest advantages of working with a manufacturer like AKT Motor is customization.
Unlike off-the-shelf parts that force you to design around fixed lengths, our HSL Series allows you to specify the Lead Screw Length (L2). Whether you need a short 50mm stroke for a gripper or a long 300mm stroke for a rail system, we can cut the high-quality stainless steel screw to your exact requirement.
Step 4: Electrical Considerations
Finally, ensure your motor driver matches the electrical specifications of the actuator.
- Current: Check the Rated Phase Current (e.g., 0.5A for NEMA 8, up to 3.0A for NEMA 23). Setting your driver current correctly is crucial to getting maximum torque without overheating the motor.
- Voltage: While stepper motors are current-driven, using a higher voltage supply (e.g., 24V or 48V) helps the motor maintain torque at higher speeds.
Conclusion
Selecting the right linear stepper motor is about finding the perfect balance between space, force, and speed.
Explore our full range of Hybrid Linear Stepper Motors today, or contact our engineering team for a custom solution tailored to your machine’s specific needs.