Eddy Current Suface Mapping

Hi Folks,

I came across this the other day:

https://beacon3d.com/product/beacon/

Its an eddy current sensor that can quickly map the bed of a 3D printer - Has anyone got any experience? Wondering if it could be a useful 3D probe replacement. Looks to have massive advantages of speed (so you could scan a much higher resolution map) but needs to scan conductive surfaces and be placed away from magnets on the gantry/spindle. I could see it being useful for metal work....

Video for interest:
https://www.youtube.com/watch?v=Gs6UC2xK5t0

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Those and the similar capacitative or inductive proximity sensors are great for things like limit and home switches. There was a demo video posted on the forum quite a few years ago showing how consistent they were. However, I would not use one as a replacement for a 3D sensor as they are not going to pick up fine detail. My 3D printer uses one to check bed level but of course that is sensing against a flat object which is ideal.

I have a fairly cheap and cheerful 3D probe that came with my second-hand CNC mill so when I needed to probe and map a surface to replicate a raised design, I just made a new probe for it with a relatively sharp tip to be able pick up detail, especially close up to almost vertical edges of features. I rewrote the probing macro (under Mach3 which I was using at the time) to speed things up a bit and it all worked pretty well. A sensor like the one shown would not have done the job.

I guess this is only relevant to 3D printing?
How do you know your gantry is moving in a perfect plane? As I see it you are only measuring the distance between the gantry and the bed not absolute plane