Sometimes the bit will not touch the probe plate when doing a single Z zero and the probe active does not come on??

OK I have it running ...... I wasn't sure how important the 104 capacitor on the C10 BOB between the pins on the probe were and I had removed it. Now I know that having the capacitor in place is very important. I reinstalled the capacitor and the probing works as advertised. What a relief I now have a fully functioning Joe's EVO CNC Router!!!! And just in time too. I received an order for a plaque this morning. Gerry thank you for your help. Without these forums I would never have been able to build my two CNCs.

Sometimes the bit will not touch the probe plate when doing a single Z zero and the probe active does not come on??

It happens so fat that you don't see it.

The capacitor is a bandaid for a noise problem. Most people don't need or use them, but in some cases, it's a much easier fix than solving all of the noise issues.