Yea there’s a thought, if you could do it repeatably that would work. I’d just be concerned about ht evenness of the magnetic field, and resulting in a mesh that’s even worse than without.
I feel like some testing and experimentation are going to be involved here. I could run several calibration cycles and do stats on the resulting meshes under certain conditions.
I’m going to fiddle with it a bit in the next week or two - if it seems feasible i will let you know so you can use the octopi to do the mapping
What about retrofitting something like this, the Rolls Royce of mechanical sensors. No problem with EMF. Works on any bed surface.
Ive seen the term BLTouch many times on this forum, so yeah why not
Preliminary evaluation, looks like its a 5vdc device, which isnt a deal breaker, just adds a power supply to the mix unless theres a 5v pin on the board in the 3dp module, cant tell off hand if it has a relay output or what.
looks like you can cut someplace on the board to make it 3.3v, so thats nice, so i would say no it doesnt have a relay, but may be compatible if run off the same power source as the controller.
BLTouch requires deploying and stowing. That requires pins that are not brought out in the toolhead, and programming to make that work that’s not currently present.
Best you could do is use the sensor but you’d have to manually raise and lower before and after.
If you are at that part, why not just use a different method altogether
^ That’s about how we got where we are. Microswitches are pretty darn repeatable, and are fine for z probing. There’s other sensors as well.
makes sense, it seems like it could be rigged in outside of all that fancy stuff without too much hassle, but more hassle than its worth considering the requirements we boiled down to
Yep OK all too complicated. My existing printer uses an ebay £10 Capacitive sensor that works very well on any sort of bed and has an 8mm sensing distance so easy to deploy and calibrate, no idea how it would fit with this device though.
assuming it is 24vdc npn output, it could be a decent upgrade for the range alone. most sensors dont have dry contact outputs but if it does even better.
i think im going to take a gander at my own version of a swapout on the probe for the hell of it. its relatively straight forward if you can boil it down to the above.
i am rather certain i could take one of the sensors we have on the shelf from our old control board and it would work out of the box for this application, they list at 50 bucks but i can get them in the low 20s, but its a bit bulky and i usually buy the pnp version these days.
sick engineering brand
5v to 36v DC NPN. 1-10mm, senses at 8mm at12v on my machine.
yep, that would work just fine. very similar to the one i was just talking about.
its an m18 threaded body which is a bit larger than the m12 we have but it could still work
just the matter of termination to the connector, finding the ideal position and mounting.
If we’re designing a new system here, it’s worth mentioning capacitive sensors have an many drawbacks as inductive. They are sensitive to temperature and humidity changes, amongst other issues. My preference is the differential IR sensor.
i am sure you have alot of insight for this and i bet your solution is going to be the best of them all
i just wana goof around with it i guess hehe, more curious about if i can do it or not than anything
you’re probably right, slapping any old prox sensor on there probably isn’t going to give the most consistent results due to the variables, but if i had the same performance as i have now, but thru the glass, it would be a step forward imo.
No doubt your right Brent but we are not dealing with a high precision device her and capacitive is fairly good and for $10, worth a play. I dont change my z offset much unless I change a nozzle or make other changes and I dont have a problem with first layer.
Hopefully you will have your IR sensor design completed by the time my device arrives.
I agree with you, I’m sure it’ll work great. I saw someone say they couldn’t get it to detect glass at 5V, but it worked at 9V or more, so at 24V it should be able to detect the window like 3ft away right? Gonna have to make everyone in the house stand still while it’s calibrating 
In general I understand the problematic of inductive problems, but for me I got the mechanical issues to 0.4mm from the highest to the lowest point which is for this machine awesome.
I would say do not interprete more than it needs. - I am not a doctor…
Please do not misunderstand, I like your going on to solve problems or figure them out, but sometimes it seems a bit too much shouting out problems that may occure, for the general user.
There’s a balance, for sure. Fortunately I know you’re not a new user and that was intended with you as the recipient. Not trying to sway your opinion on anything, just trying to understand what’s going on here. Also documenting for any other general users who stumble through here and saw your post that their mileage may vary, as there are known issues with having the temp on while calibrating.