Ultrasonic sensors

[en97]

Has anyone tried ultrasonic sensors (~USD $2 ) for alignment and bed-leveling?

They are in-expensive vs induction sensors and not as susceptible to temp changes.

Found this video: https://www.youtube.com/watch?v=AqH1JGO3n9Q accurate to 2.15 micron for proximity and 25 micron (0.025 mm) for distance

Techniques like visual alignment discussed below are used in PCB assembly by pick and place machines.

@doigal

Jeffeb3 wrote:

I would like to know more about this. I’m a software engineer that occasionally uses CV in my job. ?

Its a feature of bCNC, which I’ve been using at the local hackspace. It’s nothing super fancy or automated, basically you mount a camera on the x plate, use the router to drill a small hole somewhere and then jog to line up the camera to the hole. The software calculates the offset between the two. Then you can realign it to that point as required, and help to home the stock (or the machine if into the wasteboard.) I’m not sure of the accuracy level compared to limit switches is but for double sided machining it might be helpful.

https://github.com/vlachoudis/bCNC/wiki/Probe-Camera-Alignment

[mordiev (Aaryn)]

Search YouTube for Tom’s guide to bed level sensors. I think he compared some of those in that video with accuracy test results.

Edit. Found it.

 

[en97]

This is also a good breakdown https://www.machinedesign.com/sensors/proximity-sensors-compared-inductive-capacitive-photoelectric-and-ultrasonic