Linear Motion Calculator

How this push-pull calculator works

The actuator motor and body end are fixed to the machine frame. Its moving rod end connects to a rigid bracket on the guided carriage or load, so one inch of actuator movement produces one inch of load movement. The entered travel remains the exact animated stopping distance even when the closest catalogue actuator has a slightly longer stroke.

The guides, bearings or rails must carry the load perpendicular to its direction of travel. The actuator should supply axial push and pull force only; it must not be used as the guide or carry side load.

How push and pull force are calculated

On an incline, the calculator resolves load weight along and perpendicular to the guide. Friction is calculated from the perpendicular load and the entered coefficient, then any additional external resistance is added. Gravity can oppose one direction and assist the other, so extend and retract are calculated separately. The higher directional force, including mechanical efficiency and the entered design factor, controls actuator matching.

For a horizontal guide, weight is carried by the rails and primarily affects friction. At a vertical guide angle, gravity becomes the principal lifting load. Enter seal drag, spring force, cable drag or other repeatable loads as additional external resistance.

Measurements for this application

• Moving load length and height scale the illustrated carriage or platform.
• Available inline actuator bay is the clear pin-to-pin space for the fully retracted actuator. It increases automatically when a selected actuator needs more installation length.
• Required linear travel is the exact push or pull distance. When the selected stroke is longer, correctly configured travel limits must stop the load at the entered distance.
• Total moving load weight includes the carriage, product, brackets and every moving attachment.
• Guide incline angle is positive when extension moves uphill and negative when extension moves downhill.
• Friction coefficient and additional external resistance represent guide losses and other opposing forces.
• Design factor adds engineering allowance after the calculated loads. It is not a certified safety rating.
• Number of actuators divides the force equally only when the structure and controls provide reliable load sharing.

Choosing and locking an actuator

The selector compares the required travel and worst-case push or pull force against suitable rod-actuator families. Closest adequate strokes are ranked first, with Super Duty preferred when its stroke is within about one inch of the closest fit and Industrial preferred for high-force requirements.

Use Only use this model when an actuator family has already been chosen. Use Only use this stroke when the design must use a specific stroke. The Fit actuator button then adjusts the available inline bay without changing the entered load travel. Both views use the actual selected FIRGELLI actuator drawing.

Multiple actuators and synchronized motion

Two or more actuators need rigid load sharing and synchronized feedback control. Only feedback-capable models should be used for synchronized motion. The FCB-2 is not compatible with Industrial actuators; another compatible controller is required when synchronizing two or more Industrial actuators.

Installation and safety checks

Keep both actuator pins aligned with the guide direction, use a stiff push bracket and verify the complete retracted and extended pin-to-pin envelope. Provide physical end stops, correctly configured travel limits, guarding, emergency stopping and retention wherever loss of power could create a hazard. Confirm bracket allowance, wiring clearance, duty cycle, ingress protection, dynamic or impact loads and structural deflection before construction.