Custom Linear Actuator Design Checklist Guide: How to Spec

Your OEM product needs a custom linear actuator, and the wrong RFQ will waste weeks. A good custom linear actuator design checklist defines force, stroke, speed, voltage, duty cycle, environment, feedback, mounting geometry, testing, and approval criteria before anyone quotes tooling or samples. Clear inputs get you a better actuator and fewer prototype failures.

What is a custom linear actuator design checklist?

A custom linear actuator design checklist turns your motion requirement into engineering inputs a supplier can quote, build, and test. It keeps the conversation away from vague requests like make it stronger and moves it toward numbers.

Simple Explanation

Think of the checklist as the actuator version of a drawing package. It tells the supplier what the actuator must push, how far it must move, how fast it must travel, where it will live, and how the final part must prove itself.

Use the formula below to calculate the force target you should put into the checklist.

F_spec = F_working × SF × k_angle × k_environment

How is the checklist used during an OEM design?

You use this checklist when your standard actuator no longer fits the product envelope, force curve, connector, feedback requirement, certification target, or duty cycle. This usually happens after a prototype works once but fails repeatability, temperature, water, mounting, or life-cycle testing.

Start with our Custom Linear Actuators page when you already know you need a modified actuator. If you still need a standard frame size, compare options with the linear actuator selector and sanity-check the force with the linear actuator calculator.

Suitable Applications

Custom actuator work makes sense when volume, packaging, environment, or control needs justify the engineering effort.

• RV slide-outs that need fixed stroke, sealed wiring, and repeatable end positions.
• Medical furniture where noise, duty cycle, and controlled motion matter.
• Machine guards that need limit switches, mounting repeatability, and safe wiring paths.
• Industrial inspection equipment that needs consistent extension under changing load.
• Vehicle hatches, hood lifts, and access panels with tight mounting geometry.
• Robotics end-of-arm fixtures that need feedback, compact stroke, and predictable speed.

For supplier-level questions, read Linear Actuator Questions OEM Engineers Ask Before Choosing a Supplier and Linear Actuator Supplier Guide: Avoid Hidden Costs.

How does the checklist work?

The checklist forces 5 decisions in the right order: load, motion, environment, control, and validation. Do not start with voltage or connector style. Start with the mechanical job.

Force and stroke define the actuator frame. Speed, duty cycle, voltage, and feedback define the motor and control package. IP rating, temperature, salt, washdown, dust, and chemicals define sealing and materials. Testing defines whether the design actually survives your product.

What force should the RFQ ask for?

Ask for the actuator force after you add safety and application factors, not just the measured load. A prototype that lifts 80 lbs on the bench may need 150 lbs in production after cold grease, bad geometry, seal drag, and tolerance stack-up.

F_spec = F_working × SF × k_angle × k_environment

What does a simple example look like?

A small access lid needs 70 lbs at the actuator. Use SF = 1.5, k_angle = 1.2, and k_environment = 1.1.

F_spec = 70 × 1.5 × 1.2 × 1.1 = 138.6 lbs. Request at least 140 lbs, then choose the next suitable force class rather than designing on the edge.

How do you calculate an OEM hatch actuator requirement?

Let's calculate the custom linear actuator design checklist force target for a 48 lb vehicle service hatch. The actuator sees 95 lbs at the worst part of the lift because the mount angle starts shallow. The hatch lives outdoors, so we add environment margin.

Inputs: F_working = 95 lbs, SF = 1.5, k_angle = 1.35, k_environment = 1.15.

Substitution: F_spec = 95 × 1.5 × 1.35 × 1.15 = 221.2 lbs.

That RFQ should ask for about 225 lbs minimum at the required speed and stroke. If the hatch needs feedback and IP66, the Utility Linear Actuator gives 110 lb and 330 lb force options, 0.25 to 1.0 in/sec speed, 2 to 12 inch stroke, IP66, Hall Effect feedback, and sync compatibility. That does not mean it fits every hatch. It means the data points match the checklist better than a vague custom request.

What should your RFQ include?

Your RFQ should include the items below before you ask for price. Missing data creates assumptions, and assumptions create bad samples.

If the design needs position control, remember that Hall feedback measures rotating gearbox or encoder-disc movement, not direct rod travel. Hall sensors read alternating magnetic poles on a rotating disk. From a controller point of view, the signal acts like pulse feedback, so compatibility depends on voltage, wiring, pulse count, direction handling, and calibration.

Which actuator system should you choose?

Related FIRGELLI Products

Use these known product ranges as reference points when you build your checklist. Do not request a custom actuator until you confirm that a standard product cannot solve the job.

For broader design background, keep Linear Actuator Selection Guide: Complete Engineering Reference for Force, Stroke, Speed, and Control, Linear Actuator Wiring Diagram Guide: How to Wire 12V DC, and How to Choose a Motion Control Manufacturer: Quality, Support, and Customization Checklist in the same design folder.

FAQ

About the Author

Robbie Dickson is the Chief Engineer and Founder of FIRGELLI Automations. With a background in aeronautical and mechanical engineering at Rolls-Royce, BMW, and Ford, he has spent over 2 decades developing precision motion control systems, from linear actuators for robotics to active aerodynamic braking systems for supercars. Read the full bio at Robbie Dickson.

Practical rule: send an actuator RFQ only after you can fill in force, stroke, speed, duty cycle, environment, control, mounting, and test criteria. If 1 of those blanks stays empty, your prototype will find it for you.