K8200/3Drag Y-Axis optical end stop

thingiverse

Holder for an optical end stop on the Y-Axis with an CNY70 reflective optical sensor. The mechanical end stop tends to shake and swing, which is not only a noisy element but as well could result in unpredictable trigger. Furthermore it needs a finger on the platform, that needs to be tightly adjusted and is out of sight afterwards. The reflective optical sensor is mounted atop of the belt for the Y axis and if you place a white marker (2-3 mm width) on it in the right position (see on the pictures), it detects the endstop touches and without noise. The sharper the edges of the marker the better the repeating accuracy of the sensor. To connect the CNY70 there are several ways. I chose to do it this way: Diode with 240R to +5V and GND. Transistor with Collector to +5V, emitter to S and with 2.4 MOhm to GND. Deactivate Y-Axis Pullup in Software.