RATTMMOTOR Normally Closed Mach3 CNC Automatic Tool Sensor

This is not a Normally Open tool sensor. It is NC. I've ascertained that the only way it could be a normally open sensor is to have a built-in FET circuit. Aka would need to be a six-wire unit requiring voltage to invert the state. 6-wire versions provide both NC and NO states.

My initial order had some confusion with the item I received but the seller to care of the issue right away. I am very happy with the overall service. The Z-Axis gauge works well and the tests I have done so far show it has solid repeatability. I don't have an automatic tool changer. This allowed me to seriously streamline my tool changing process and got rid of a huge source of errors as I switched out tools. Overall it is well worth it. Note - I initially bought this for use on a 4x4 CNC Router running on Mach3. I have since shifted over to UCCNC and am very happy with the change. This Z-Axis probe worked fine on both. Actually even better on UCCNC since I have more probe inputs.

What was shown seems to be the product I was shipped but the dimensions are way off. The two hold down screws are M4, not M5 (advertised as 5.3 mm when in fact what I was shipped is 4.05 mm). Not a good start to a precision instrument. I will update this as I get it installed. UPDATE: I am happy with the repeatability. The unit is worth the money. It looks crooked when sitting on a flat surface and it is. But it's been adjust to actually be flat for both top and bottom but the body and slide switch are slightly off center. I wouldn't be shocked to learn they are discarded from a manufacturer because they have visual defects but are still usable. Maybe when I have more money I will get a nicer unit but right now it's returning good consistent numbers. NOTE: the mounting screw holes are M4. The compressed air system is a M5 metric pneumatic connector. You can get them that will allow a 6mm the OD (4mm ID) tube and get a 1/8 NPT to 6mm OD fitting for your solenoid if you have a standard USA system like I do.

This arrived dead. I decided to repair it rather than return. The internal mechanism is two microswitches so the primary sensor is not a piezoelectric as implied by the circuit diagram. One of the wires was loose. I resoldered them all as they were soldered at an angle and almost short circuiting and added some insulation. Also adjusted the microswitch position. Mechanically it is not terrible.

This is not a Normally Open tool height sensor like the title said. I have tested it and both the main and the overtravel contacts are Normally Closed. I have paid premium price thinking that I am getting the correct sensor. Now my machine build is delayed! .... False advertising. Buyers beware!

works as it should. very good product even at a low cost.

I’m editing this. I gave it 2 stars at first. But after getting a replacement with the same problem, I’m dropping to 1 star with the hopes that some day Amazon will allow a 0 star review. Don’t waste your money, if you’re thinking “I can just glue it on” you’ll sacrifice accuracy if the popped off piece isn’t glued on perfectly flat. You’d think something in this price point wouldn’t be held together with brittle glue. But seems it is.

Not like described, only 4 wires 2 contacts, has no led indicator, no fast coupling, have to rectify the base irregularities and the overtravel switch get stucked sometimes.