End-Stop Limit Switch

Question

Problem: End-Stop Limit Switch. Solve this hands-on electronics task on EWskills.

Accepted Answer

1. Component Purpose

In a linear motion system (e.g., a CNC axis, 3D printer bed, or actuator), the mechanism must stop at the end of its travel. A limit switch detects when the moving part reaches the end position.

When the mechanism presses the lever, the switch actuates and sends a signal to the controller, which then stops or reverses the motor. This prevents mechanical damage from over-travel.

A snap-action (microswitch) mechanism gives a crisp, repeatable switching point with very low hysteresis — important for accurate position detection.

Required: SPDT · On-Mom · Lever Straight · ≥2A DC · ≥24VDC · 50–120gf · ≥1M cycles · Through Hole

2. How to Find It on DigiKey

Go to DigiKey.com → Switches → Snap Action, Limit Switches

Apply these filters:

Circuit → SPDT
Switch Function → On-Mom
Actuator Type → Lever, Straight
Current Rating (Amps) → 2A or higher
Voltage Rating - DC → 24V or higher
Mounting Type → Through Hole
Part Status → Active

Tip: Operating force matters for limit switches. 50–120gf is light enough that the mechanism doesn’t need to push hard, but firm enough for reliable actuation. Too light and it may false-trigger from vibration.

3. Key Specifications & What They Mean

Specification	Required	Why
Circuit	SPDT	Gives both NO and NC outputs.
Switch Function	On-Mom	Momentary; returns when lever released.
Actuator	Lever, Straight	Lever arm extends for easy mechanical contact.
Current Rating	≥2A DC	Handles 24V DC control circuit load.
Voltage Rating	≥24VDC	Matches control circuit voltage.
Operating Force	50–120gf	Light enough for mechanism; resists vibration.
Mech. Life	≥1,000,000 cycles	High endurance for repetitive motion systems.
Mounting	Through Hole, PC Pin	Soldered to PCB or panel-mounted.
Temp Range	−40°C to +85°C	Industrial operating conditions.

4. Selecting a Safe, Production-Ready Part

The filtered list will show matching parts. Before you pick one, check: Is it Active? Is stock available? Is the manufacturer reputable? Is a datasheet available?

Full checklist: How to Select a Safe, Production-Ready Component — EWskills Guide

5. Filtered DigiKey Link

➡ View Matching Parts — Snap Action, SPDT, Lever Straight, ≥2A, ≥24VDC

49. End-Stop Limit Switch