K40 & ESP32 (Water cooling and more)

I look back to my old dusty K40, while my ESP32 are in the slow boat…

About 6 years ago, when modifying my K40 with a smoothie board, I had a chat with @Arthur_Wolf to implement a water flow sensor, the result was it was needed to code for the Smoothieware, a step too far on my knowledge, the water flow sensor stay in the box.

Here is the 2021 idea :

What about a water control for the K40 based on flow and temperature?

  • a color led ring to show the temp range and where you are in it . (Blue too cool range, green operating range, yellow dot actual water temp, red too hot range)
  • auto switch off if under flow speed or over temp threshold (all k40 or just laser interlock)

If the piloting software is open too it, it could display message on your screen like “close the door to run the job” or “water too hot” (any interlock detected, etc …) This thing could be possibly extended further (remember that: https://youtu.be/arjRtCjI9AQ?t=140) servo (defocus or flip object)

So the ESP32 look a perfect match for the K40 (independent of your controller board), within the low cost K40 philosophy.

Just a brain storming for now, let me know what do you think about it .

Why not doing it all together as a project community, as we did in the past ? (Nudge to Laserweb or other K40 softwares) @cprezzi

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This was something I threw together years ago using an atiny45

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I remember that ;-))

the advantage of ESP32 is far better hardware (processing power, ram, network, pin out).
Network is an interesting point, as it will allow communication with the piloting software -> this open huge possibilities.
One ESP 32 card (<10usd) can do all arduino compatible like you did, local hardware improvement (water flow, temp control, any interlock … all at once) and open for a next step (defocus, etc …)

it’s also independant from your controller board, it work in parrallel as a second controller ;-))

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Not sure if you are thinking of an integrated K40 management controller

Multiple times I started down the road of building a controller that manages all things not covered by the controller and its software.
I have heard that others have built one but never saw anything real …

I have stopped short each time I thought through this project because I have most of these things implemented and never sensed that any one would pay for such an integrated thing.
Also after spending many hours helping K40 users modify machines, I think that a large % of users bought a K40 due to its low cost not because they wanted to or could build something. Most are not able to install something like this without lots of help… most do not want to pay much for such a thing. As an example MOST K40 users won’t install interlocks :frowning: !

Sure the ESP and most any recent arduino types are a fit. Some come with a display integrated . I don’t think the challenge is making this thing its whether there is enough demand to make it worth the effort :).

Of course I have always thought the right way to do this is in the controller :).

An Integrated Controller to Manage Things like:

  • Control panel functions for the LPS
  • Laser tube current control, measurement & alarm
  • Laser power, job override setup, enter, save, recall.
  • Laser usage meter
  • Coolant, laser tube, cabinet; temp measurement, action and alarm
  • Interlock management and alarm
  • Air assist on/off, measurement and adjustment
  • Pointer control
  • Cabinet lighting
  • Lift system local (joystick) and remote control with integrated controller interface (I actually built this for mine)
  • Evacuation fan flow detection
  • Fire detection and management
  • Mobile app interface
  • Mobile app

@donkjr, you are right, it’s part of k40 philosophy (& makers) to keep the cost as low as possible.

The service of a bunch of parts (<20€or$) is hudge, very simple to assemble, connect the 3 wires of temp sensor and 3 wires of flow sensor and the Led ring on the esp and you are done. the rest is to DL the code made from 3 arduino sketches, power it and set your wifi credential. if the code is ready made it’s a walk in the park.
Going further will need more work, and depend on the piloting software (if dev accept to add it), but have huge potential.
So it’s not a developed specific K40 controller which cost $$ to make & sell. just a common board where you can connect all sort of thing, and with a bit of software become de facto a k40 separated controller.

most of your list could be done. even an integration with Home assistant/NodeRed ;-))


I’ve done several addons like manual bed hight adjustment, flow sensor, temp sensor etc.
I even hacked the protocol of the widely used aliexpress USB / wireless pendant to use it with LaserWeb.
I also designed an external DRO / remote for grbl (with path through serial).

I’m open to deliver my experience to a community project.