Compact lead screw linear actuators are motorized or hand-crank linear guides that use either ball bearing profile rails or self-lubricating Gliding Surface Technology (GST) carriages to move and accurately position loads in confined spaces. PBC Linear's Compact Series features a low-profile 23mm height for machine automation, positioning systems, and applications with limited installation space. The integrated lead screw drive converts rotary motion into controlled linear carriage travel, combining guidance and positioning within a compact assembly.
CNC precision-rolled lead screws are available in 6, 8, and 10mm diameters, with lead accuracy of 0.003in/ft (76µm/300mm). Made from 300 Series stainless steel with a PTFE coating to reduce friction and wear, the screws work with Constant Force Technology™ anti-backlash nuts that maintain consistent preload, minimize axial play, and improve positioning repeatability over time.
Ball bearing profile rail actuators use recirculating ball bearings to provide high rigidity, precise guidance, and greater support for cantilevered loads without the 2:1 ratio limitation of plain bearings. Their dynamic coefficient of friction is below 0.010, making them suitable for applications requiring higher speeds and accurate positioning. GST actuators instead use self-lubricating FrelonGOLD® PTFE liners beneath the carriage, providing quiet gliding motion without metal-to-metal contact. These plain bearing systems damp vibration, tolerate temperature extremes and particulates, and eliminate external bearing lubrication. GST carriages must observe the 2:1 ratio rule but avoid the recirculating bearing failures associated with contamination or shock loads.
Drive configurations include NEMA 17 and NEMA 23 stepper motors, manual hand knobs, and stub shafts for customer-supplied actuation. Motorized configurations provide programmable movement and positioning when paired with compatible controls, while hand-crank versions allow manual adjustment without electrical power. Protective cover options are available for applications requiring additional shielding from debris, with overall assembly height depending on the selected cover.
Compact Series lead screw actuators are used in laboratory automation, medical equipment, robotics, packaging machinery, and automated positioning systems. The choice of ball bearing profile rail or GST guidance allows engineers to match load requirements, operating environments, and positioning needs within the same compact actuator platform.
- Compact lead screw-driven linear actuators for moving & accurately positioning loads
- Motorized or hand-crank operation with ball bearing profile rail or GST guidance
- Ball bearing profile rail provides greater rigidity and cantilevered load capacity
- GST plain bearing carriage for quiet, self-lubricating gliding motion
- Standard low-profile height: 23mm without protective cover
- Lead screw diameters: 6mm, 8mm and 10mm
- CNC precision-rolled lead screws with 0.003in/ft (76µm/300mm) lead accuracy
- Lead screw material: 300 Series stainless steel with PTFE coating
- Constant Force Technology™ anti-backlash nuts minimize axial play
- Drive options: NEMA 17/23 motors, manual hand knobs or stub shafts
- Ball bearing profile rails support cantilevered loads without the 2:1 ratio limitation
- Ball bearing guidance with dynamic coefficient of friction below 0.010
- GST FrelonGOLD® PTFE liners eliminate metal-to-metal contact
- GST guidance provides vibration damping and resistance to particulates
- GST plain bearing systems must observe the 2:1 ratio rule
- Standard carriage and rail cross section: 23mm × 55mm
- Maximum horizontal bearing load: Up to 5,350N (1,202lb), depending on configuration
- Maximum stroke length: Up to 1,016mm (40in), depending on configuration
- Protective cover options available to shield components from debris
- Applications: Laboratory automation, medical equipment and robotics
Frequently Asked Questions
What is a compact lead screw actuator?
A compact lead screw actuator is a space-saving linear guide that uses a rotating lead screw to move and accurately position a guided carriage along a straight axis. Drive options include stepper motors, manual hand knobs, or stub shafts for connection to customer-supplied drive systems.
What is an anti-backlash lead screw nut?
An anti-backlash nut reduces axial play between the lead screw and nut by maintaining preload against the screw threads. PBC Linear's Constant Force Technology™ anti-backlash nuts compensate for wear to improve positioning repeatability over time.
What is the difference between ball bearing profile rail and GST linear actuators?
Ball bearing profile rail actuators use recirculating ball bearings for high rigidity, low friction, and greater cantilevered load capacity. Gliding Surface Technology (GST) actuators use self-lubricating FrelonGOLD® PTFE liners for quiet gliding motion, vibration damping, and operation in environments exposed to dust, debris, and temperature extremes.
Which compact linear actuator is better for cantilevered loads?
Ball bearing profile rail actuators generally provide greater rigidity and cantilevered load capacity than GST plain bearing configurations. Their recirculating ball bearing guidance is not subject to the 2:1 ratio rule that applies to plain bearing systems.
What is the 2:1 ratio rule for GST linear actuators?
The 2:1 ratio rule states that the distance from the applied driving force to the bearing centerline should generally not exceed twice the effective bearing separation in the direction of travel. Exceeding this ratio can increase friction and cause binding in plain bearing systems. Ball bearing profile rails are not subject to this same limitation.
What is Gliding Surface Technology (GST)?
Gliding Surface Technology (GST) is PBC Linear's plain bearing guidance system using self-lubricating FrelonGOLD® PTFE liners. The carriage glides along the rail without metal-to-metal contact, reducing friction, wear, vibration, and external lubrication requirements.
Do GST compact linear actuators require lubrication?
The FrelonGOLD® plain bearing liners are self-lubricating and do not require external bearing lubrication. The lead screw, motor, and other components may have separate maintenance requirements.
What is the difference between motorized and hand-crank linear actuators?
Motorized linear actuators use an electric motor to rotate the lead screw for controlled movement and positioning. Hand-crank actuators use a manually operated knob to rotate the screw, allowing carriage adjustment without electrical power or a motor controller.
Can Compact Series linear actuators be supplied without a motor?
Yes. PBC Linear offers Compact Series configurations with motor mounting interfaces or stub shafts for customer-supplied actuation. Integrated motor and manual hand-knob configurations are also available.
What motor sizes are available for Compact Series linear actuators?
Compact Series actuators support selected NEMA 17 and NEMA 23 motor configurations. Available motor mounts, integrated motors, and connection options depend on the actuator model.
What lead screw diameters are available?
PBC Linear Compact Series lead screw actuators are available with 6mm, 8mm, and 10mm screw diameters. Screw diameter, lead, and rail length depend on the selected configuration.
What does lead mean on a linear actuator screw?
Lead is the linear distance traveled by the nut and carriage during one complete revolution of the lead screw. For example, a 2mm lead moves the carriage 2mm per screw revolution. Lead affects travel speed, mechanical advantage, and positioning resolution.
What is the lead accuracy of Compact Series linear actuators?
PBC Linear Compact Series CNC precision-rolled lead screws provide a lead accuracy of 0.003in/ft (76µm/300mm). Lead accuracy describes the difference between actual and nominal linear travel over a specified distance.
How tall are Compact Series linear actuators?
The standard uncovered Compact Series actuator has a low-profile height of 23mm. Optional protective covers increase the overall assembly height, depending on the selected configuration.
What is the difference between horizontal bearing load and actuator thrust?
Horizontal bearing load refers to the load supported by the actuator's linear guidance system. Actuator thrust is the axial force generated through the lead screw drive. A bearing load rating does not indicate the available driving force, which depends on the screw, motor, and operating conditions.
What applications use Compact Series linear actuators?
Compact Series lead screw actuators are used in laboratory automation, medical equipment, robotics, packaging machinery, and automated positioning systems. Ball bearing profile rails are suited to applications requiring greater rigidity and cantilevered load support, while GST guidance is useful where vibration, debris, and external lubrication are concerns.
