Replace Omron inductive probe with Klicky

[kharrisma]

Probably a duhhh question, but I'd rather ask it and feel foolish than just go ahead... and let out all the magic smoke!

Omron probe has three leads (V+, signal, ground), and is powered by 24V (in a NiteHawk SB toolhead.)  Klicky is just a limit switch wired in a N/C configuration.  So, I've three pins in the probe connector... and two coming from the switch.

Question is: which two?  Nothing is specified in the Klicky documentation (that I can find, anyway.)  My first guess is 24V and signal... but I really hate to guess when it comes to electronics.  Won't be 24V and ground, that much is certain.  My only othe possibility would be signal and ground, but I really can't see how that would work.  I DO have the schematic for the NiteHawk SB... but try as I might, I can't locate the thing, and can't find one with searches either.  Figured it couldn't hurt to ask here while I continue to search for the schematic!   

My big concern here is that I'm familiar with how this N/C switch setup works for limit switches *in my SKR Mini E3,* which uses the 3.3 volt rail to send voltage to the MPU.  Don't know if the Raspberry Pi 2040 onboard the NiteHawk is "hardened" to cope with 24V or not.  I'd guess so, since that's the supply FOR the probe... but again, guesses are not the best way to gl here.

[Penatr8tor]

You only need signal and ground for the klicky. 24v is not needed and should not be connected, unless... you get a PCB klicky, then I believe that the power lead is configured for 5v and it's used to power a status LED.

[RopusLongus]

Normal (as ex klicky user) the signal and ground pin are all you need for the function. There are different versions of the pcb for 12 and 5v if I remeber right. But to use it you only need signal and ground.

 

 

[Penatr8tor]

1 minute ago, RopusLongus said:

Normal (as ex klicky user) the signal and ground pin are all you need for the function. There are different versions of the pcb for 12 and 5v if I remeber right. But to use it you only need signal and ground.

I think the PCB klicky is definitely worth the cost (under $20 on Amazon).

[RopusLongus]

I agree fully. 

If you go klicky then the pcb version. Some sell them in 2 packs and all you need is with it. 

I use tap now but one of the disadvantages is that if you use other then rough pei sheets it will give marks on every other smooth sheet. 

Or like I do it : a metal flex plate where I use gloo or 3dlak on. Not perfect but smooth enough.

With klicky is a good choice if you use different plates and best is it's not so temp reliable and it works on every surface. 

 

Edited August 11, 2025 by RopusLongus

[Penatr8tor]

I'm surprised someone hasn't used a Cherry MX keyboard switch for a probe yet. 

[RopusLongus]

Don't wake up sleeping dogs. 

I had those micro dot switches in my hand I used for furry Cosplay they are perfect for a verry flat pcb

[claudermilk]

Having done both Klicky the hard way and PCB Klicky, PCB is much easier. I would expect they should be able to take either 5V or 24V now--mine is an earlier 5/24V revision, so it just plugged in where the OG inductive would go.

I would swear I saw somewhere someone did use a keyboard switch.

[kharrisma]

Thanks for the input, plus the recommend for the PCB version.  Wasn't aware of that one.  I finally found the schematic, and yep; it works just like X & Y stops, voltage and all.

 

3.3 volts out pin#2, back to ground via pin#1.  Switch goes open, 3.3V has nowhere to go but "Probe," pin 13 / GPIO 10.  A bit surprised to NOT see a low-value resistor (100 ohm or so) where the word "PROBE" is; there's one on the control card.  Anyway, piece of cake... when you have the documentation!

And yeah... those cherry keyboard switches are nice.  I have a 1980's IBM "M" keyboard that I'm putting a Soarer's converter into so it'll interface with modern equipment.  That should be great!  SO much better than today's membrane keyboards!!

[RopusLongus]

I always woulp prefer a microswitch keyboard. Love the sound and easy to replace. 

[Penatr8tor]

1 hour ago, RopusLongus said:

I always woulp prefer a microswitch keyboard. Love the sound and easy to replace. 

That's exactly what I use. Keychron K10 with super brown switches. I even tried some switching out the keycaps.

[kharrisma]

My "M" keyboard is one of those five-pound IBM battlewagons, circa 1986.  Thing is a beast, I could probably break masonry blocks with it!  Not sure exactly which switches are used in it, didn't tear it down that far.  

Edited August 12, 2025 by kharrisma

[claudermilk]

Dang does that picture bring back memories! Yeah, those things were battleships!

[lawson.brian]

22 hours ago, kharrisma said:

Probably a duhhh question, but I'd rather ask it and feel foolish than just go ahead... and let out all the magic smoke!

Omron probe has three leads (V+, signal, ground), and is powered by 24V (in a NiteHawk SB toolhead.)  Klicky is just a limit switch wired in a N/C configuration.  So, I've three pins in the probe connector... and two coming from the switch.

Question is: which two?  Nothing is specified in the Klicky documentation (that I can find, anyway.)  My first guess is 24V and signal... but I really hate to guess when it comes to electronics.  Won't be 24V and ground, that much is certain.  My only othe possibility would be signal and ground, but I really can't see how that would work.  I DO have the schematic for the NiteHawk SB... but try as I might, I can't locate the thing, and can't find one with searches either.  Figured it couldn't hurt to ask here while I continue to search for the schematic!   

My big concern here is that I'm familiar with how this N/C switch setup works for limit switches *in my SKR Mini E3,* which uses the 3.3 volt rail to send voltage to the MPU.  Don't know if the Raspberry Pi 2040 onboard the NiteHawk is "hardened" to cope with 24V or not.  I'd guess so, since that's the supply FOR the probe... but again, guesses are not the best way to gl here.

I use the Fystec klicky PCB and the 24v is an optional connection for a led indicator - it has no other function. I only used G and gpio. I have my 2.4 using the Voron endstop/Klicky PCB mix and the Trident running klicky pcb for both z endstop and probe. Both have been reliable and I will likely convert the 2.4 over to only use Klicky. The main issues that can crop up is the probe mount in the Stealthburner can come loose over time as well as the magnets so you need to check every couple of hundred hours of print time. It pays to use locktite blue on the magnet screws if possible. At £4 ($5) from China they are pretty much a throw away item so it is easy to have a couple of spares kicking about.

I'm too cheap for Beacon at present but may blow the moths out of my wallet at some stage

Both are running on Nitehawk boards - one SB and one 36.

[Penatr8tor]

If you compare the IBM to the Keychron I have... Apart from a more modern aesthetic, it's the same keyboard. The old IBM used mechanical switches and is the impetus for all of these new klicky keyboards. The key switches and caps that most closely match the IBM are Cherry MX.

Keychron makes an number of variants depending on whether you want a compact or full with or without a number pad. It's essentially a platform that can be modified any way you want. You can swap out the key switch type to something with a lighter feel, etc. and you can also swap out the key caps so there's customizability. Weight for the K10 with aluminum frame is 3.3 pounds (1.5k) the IBM, I would guess, is probably 2-3 lbs.

[Penatr8tor]

14 minutes ago, lawson.brian said:

I'm too cheap for Beacon at present but may blow the moths out of my wallet at some stage

Then go with the Cartographer ($35 + shipping) or the BTT Eddy Duo ($33 on Amazon). They all do the same thing the only difference, IMO, is that the Beacon is the most mature of the current offerings and doesn't suffer from the same growing pains (which you'll also have to suffer thru) while the copycats catch up. So, I don't know... is it worth an extra 40 bucks to get a Beacon? That's something you've already decided on. I'm already in for a grand + on my printer builds and an extra $40 isn't going to financially kill me.

[kharrisma]

1 hour ago, lawson.brian said:

I use the Fystec klicky PCB and the 24v is an optional connection for a led indicator - it has no other function.

Thanks for that clarification; it's not made clear (to me, anyway) in the documentation on github.  I'd prefer it to be reversed, for the LED to come on when the switch is triggered open, rather than always-on, going out when it's triggered.  Or do I have that backward??  Little video clip appeared to work that way.

@lawson.brian - - I originally got the '36, but there was some issue with it, it wasn't detected no matter what I did.  Was on the fence at the time whether to stick with the Hero Me printhead or switch to the Stealthburner, and that decided it for me.  Stealthburner+NiteHawk-SB+Klicky (original for now, PCB on the way.)

 

RE: Cartographer/Beacon... am I incorrect in assuming that these inductive probes are affected by heat, as in a heated enclosure (printing nylon or some other hi-temp filament)??  My Omron is inductive, which is fine for the moment as I'm using a PEI coated spring metal sheet, but I also like to print on glass as well, and the Omron ain't going to work with that, which is the reason I finally came down on a mechanical switch - - it pretty much covers all the bases, minus the speed with which you can mesh your bed.

[kharrisma]

Original IBM "clickers" used what they called a "buckling spring" switch; not sure if that's the basis for *all* the mechanical switches used today.  I also have a Red Dragon clicker keyboard ($5 at a yard sale), and while it clicks, it's absolutely not the same as the IBM.

[Penatr8tor]

1 minute ago, kharrisma said:

Cartographer/Beacon... am I incorrect in assuming that these inductive probes are affected by heat,

They can be. For the Beacon it's 115c max. I print ABS/ASA at 240c with a 110c bed with zero issues. I don't expect an issue with higher temps only because I have yet to hear of that even being a problem but...

The greater fool theory says that... No matter how fool proof the device has been made.  The universe will manifest a greater fool that will 100% go over the specified max temp and post that the device is a piece of crap on social media because it failed.

Gotta love the universe. 

[Penatr8tor]

9 minutes ago, kharrisma said:

Original IBM "clickers" used what they called a "buckling spring" switch; not sure if that's the basis for *all* the mechanical switches used today.  I also have a Red Dragon clicker keyboard ($5 at a yard sale), and while it clicks, it's absolutely not the same as the IBM.

There's a ton of different switches to choose from these days but I don't think you can get snap-in buckling spring switches. With all the choices... do you really need them though? I guess the answer would be yes for some people but for now, there doesn't seem to be enough interest to bring them back.

I'm using Gateron brown in mine and they're fine IMO, but with my ham fisted fat stubby sausage fingers it probably doesn't matter, at least I can't really feel it..

[lawson.brian]

16 hours ago, Penatr8tor said:

Then go with the Cartographer ($35 + shipping) or the BTT Eddy Duo ($33 on Amazon). They all do the same thing the only difference, IMO, is that the Beacon is the most mature of the current offerings and doesn't suffer from the same growing pains (which you'll also have to suffer thru) while the copycats catch up. So, I don't know... is it worth an extra 40 bucks to get a Beacon? That's something you've already decided on. I'm already in for a grand + on my printer builds and an extra $40 isn't going to financially kill me.

Purely a tongue-in-cheek comment with regards to the Beacon cost (£80 each does add up for 3 printers). Both BTT Eddy and Cartographer were early release when I initially looked. Probably worth another look now that both have matured somewhat from their release. The development of Beacon touch is what caught my interest - looks like the best of both worlds!

[Savate]

15 minutes ago, lawson.brian said:

looks like the best of both worlds!

cartographer also has a touch mode (and it works fine)

[claudermilk]

As a side note, my mostly-OG Tap PCB has the LED always on, it just switches from blue to red when triggered (or is that the other way 'round?). It's nice to have the visual confirmation & helped with early days troubleshooting.

I know the whole mechanical keyboard thing is yet another rabbit hole. I like my Logitech K350 well enough to stick with that for now. My son went and swapped all his keycaps to some anime-themed stuff so now you better be an expert touch-typist since there's no letters anywhere.

[kharrisma]

Yeah... I can see that!  I really messed up some years back somehow, and wound up changing my keyboard to Dvorak, and was suddenly typing total gibberish and couldn't understand why!  Was fearful I had contracted a virus or worm of some kind!  Thankfully I have a Linux 'backup' machine for when Windows gets squirrely, and with that I managed to figure out what I did.  Never did figure out HOW I did it though...

[Penatr8tor]

1 hour ago, claudermilk said:

My son went and swapped all his keycaps to some anime-themed stuff so now you better be an expert touch-typist since there's no letters anywhere.

 Don't ask me how I know...