CNC Tool Length Sensor / CNC Probe

prusaprinters

<p>This is a simple tool length sensor for a CNC router to set the Z-height to zero. At the heart is a Cherry MX switch that is used in mechanical computer keyboards that have an excellent precision.</p><p>The Cherry switch is connected to a cable that will be connected to the controller of your CNC router. In the mode for using the probe, the Z-axis will move down to the red dot (small key cap) and once the switch is closed it stops moving and sets the Z-value to the predefined height of the device. The height is roughly 21.5mm including the cap and must be measured once to get the actual height when the switch closes. Tests have shown that it's very reliable. Hover it is not a super precise device. I measured a repeat accuracy of about 5/100mm which is more than enough for a CNC router that is used to cut wood or GRP.</p><p>I added three holes in the enclosure to add 4x10g weight (for car tires) to give it a solid touch.&nbsp;</p><p>The enclosure should be printed upside down with support on the build plate only. All other parts do not need any support. As the Cap is rather small I used my PRUSA MINI+ with a permanently installed 0.25mm nozzle. Quality with this equipment is outstanding.&nbsp;</p><p>The first prototype was printed with a MK3S+ w/ 0.4mm nozzle and .2mm Quality setting. All PLA (Mainly Galaxy Black).</p><p>All parts printed with 100% infill to add weight.&nbsp;</p>