/diy/ - Do It Yourself

Fucking shit. I can't seem to be able to get rid of probing noise when i'm probing pcbs for milling.

Basically the pic bellow is a height map of the probed pcb (since pcbs are never perfectly flat, so you need to lift the endmill (drill) up and down to make sure the traces you mill have correct sizes, hence the need for the height probing).

if you run the probing routine several times, the resulting map should always look exactly the same, the problem is that i usually get one or two spots that differ, for example there would be small red spot in the dark blue area in the pic which is due to some sort of noise that makes the probe fire early. (The probe simply shorts pulled up input pin to ground by touching the pcb, the probe is literally just two wires, one connected to pcb, other to the endmill bit)

I tried to change the probe cables and used a shielded usb cable. I even tried to connect the shielding of the cable to earth ground, but the interference spots are still there.

How the fuck do i get rid of the noise issues?