Taiss 2PCS LJ12A3-4-Z/BX Proximity Switch 3D Printer Inductive Proximity Sensor Detection Switch NPN NO DC6-36V 4mm Normally Open

I love these. I use them along with some 100 pound pull magnets to mount them on my tractor to indicate when it is in 4x4 and when the PTO is engaged.

I ordered the two-pack and received both, well packaged. Handy wiring info attached to the harness. I bench tested the sensors and they triggered down to 4 VDC, so I was encouraged that they would work with my 5V Arduino controlled CNC router. I used the first one as a Limit/Homing switch for an upgraded Z axis. Now that I know they work for my intended purpose, I'll be ordering another two-pack to upgrade the other axes from the original mechanical, normally-open limit switches to these normally-closed inductive switches. A NC setup is safer and contactless switches are more accurate, so a win-win for me.Two bonuses are these look awesome on my project, and they have a wide range of adjustability, so mounting them is a snap.

Trianing

works on tachometer used instead of magnetic pickup . magnet kept picking up shavings from lathe

These worked just fine as an early detection device for a slipping gearbox mount. You just have to connect them correctly. I purchased NPN proximity sensors which are not wired the same as PNP. If connecting to a relay PNP should be wired with the black wire in A1 and A2 going to ground, or reverse for NPN; black wire to A2 and A1 going to positive.

Unfortunately, I couldn't get this to work with my printer. The fact that it is normally open and requires a way to regulate 12v and 5v, it is not worth the risk and trouble of "trying" to make it work.

using it as a Z probe on my ender 3. the description says "6v-36v" but it works fine off 5v.according to the deviation test this probe has 0.001mm deviation

Using as homing sensors for my CNC machine. They are the same sensors as the Longmill CNC machine.