
Simple, repeatable, reliable
The mechanical endstop is a simple solution to a simple problem. We want to be able to detect when an X/Y/Z stage has reached its minimum or maximum. Instead of messing with flags or complicated light beam interruptors, we use a mechanical switch. If we place the switch in the path of the stage, then the stage itself will simply close the switch when it moves against it. Other than properly positioning the switch, we do not need to modify the stage at all. If you're worried about reliability, you can sleep well at night. The switches we use are rated for 1 million operations before failure. Since we only use the switches once per print, that means you'll be able to do one million prints before having to replace the switch.
Interfaces
Switch
The mechanical endstop uses a lever switch to detect when it is activated. The switch is wired up so that when activated, it pulls the signal to LOW. There is also an LED on the board that will light up when the switch is activated. This can be a big help when debugging.

Interface
The mechanical endstop uses a standard 4 pin .100" pitch header and accepts a standard, old-style CD-ROM audio connector cable. The pinout for the cable is detailed below:
Pinout
PIN | NAME | FUNCTION |
---|---|---|
1 | 5V | This pin provides 5V to the endstop switch. |
2 | GND | This pin is connected to ground on the endstop. |
3 | GND | This pin is connected to ground on the endstop. |
4 | SIGNAL | This pin is the output of the endstop. LOW = endstop activated, HIGH = endstop normal. |

Schematic

Partlist / BOM
Source
The Mechanical Endstop v1.2 is Open Source Hardware and is licensed under the GNU GPLv3.
Download
History
The Mechanical Endstop v1.2 is an original design by MakerBot Industries.