This roller lever KW11-3Z pairs the classic snap-action micro switch body with a sprung metal lever and a free-spinning roller wheel, rated 5A at 250VAC. The wheel rolls smoothly over cams, carriages and sliding parts instead of scraping against them, making it the pick for positions where something travels across the switch. Its three terminals (common, normally-open and normally-closed) let you wire it as either a normally-open or normally-closed trigger, and the snap-action mechanism delivers a crisp, repeatable click every time.
- SPDT contacts with one common (C), one normally-open (NO) and one normally-closed (NC) terminal
- Roller wheel on a sprung lever for smooth, low-friction triggering from moving parts
- Rated 5A at 250VAC, handles mains or low-voltage DC switching
- Snap-action mechanism for a sharp, repeatable trigger point
- Long life, rated for over 1,000,000 operating cycles
- Low contact resistance of 50 mOhm or less
- High insulation resistance of 100 MOhm or more
- Dielectric strength 1000VAC for 1 minute
- Standard KW11-3Z body and mounting, drops into common endstop brackets
- Ideal as a 3D printer or CNC endstop, door sensor or travel limit switch
Specifications
What's in the pack
Quantity as selected. Ready to wire, no extra components required.
Great for
Getting started
- Identify the three terminals
The rear of the body is moulded NC, NO and C, so there is no guesswork: the pin marked 1 is normally-closed (NC), the centre pin marked 3 is normally-open (NO), and the pin marked 2 is common (C). Confirm with a multimeter in continuity mode if you are unsure.
- Choose NO or NC
Wire C + NO for a circuit that closes (turns on) when the roller is pressed, or C + NC for one that opens (turns off) when pressed. For 3D printer and CNC endstops, NC wiring is often preferred so a broken wire reads as triggered.
- Mount the switch
Fix it through the two mounting holes so the roller meets your moving part right at the travel limit. Angle the switch so the part rolls onto the wheel rather than hitting it end-on, and leave a little over-travel so the switch fully actuates.
- Test the click
Press the roller by hand. You should feel a firm snap and hear a distinct click as the contacts change over. Confirm the switching with a multimeter before wiring it into your machine.
Common questions
When should I choose the roller version?
The roller wheel is ideal where a cam, carriage, gantry or sliding part travels across the switch rather than pressing it straight on. The wheel rolls over the moving surface with very little friction or wear, giving smooth, reliable triggering. If your target presses the switch head-on, the plain or lever KW11-3Z versions suit better.
What do the three pins do?
This is an SPDT (single-pole double-throw) switch. The common terminal (C) connects to the normally-closed (NC) contact when the switch is at rest, and to the normally-open (NO) contact when pressed. You only ever use two of the three pins for a given circuit, C plus whichever of NO or NC you need.
Can I use it as a 3D printer or CNC endstop?
Yes. This is the roller version of the hugely popular KW11-3Z endstop, used across 3D printers, CNC machines and laser cutters. Wire C + NC (or C + NO to match your board's logic) and connect it to your controller's endstop input.
How much can it switch?
It is rated 5A at 250VAC, so it comfortably handles low-voltage logic signals (3.3V / 5V), DC loads and mains-voltage switching within that limit. Stay within the rating and observe normal mains-voltage safety practice when switching AC.
Good to know: Two of the three terminals are used per circuit, common (C) plus either NO or NC. For machine endstops, NC wiring is commonly preferred so a damaged wire fails safe as "triggered". The switch is rated to 5A / 250VAC; keep within that limit and follow standard mains-voltage safety practice when switching AC.