New IR-Probes -> false Triggerheight



  • Hi everyone...

    I got new IR-Probes and i have a problem now.

    With smooth surfaces, I get a very large offset, but that had always worked ...

    It seems to me that when Z-probing the distance is already triggered at about 10mm too early. What I've noticed, I did not see a Led light when triggered.
    After triggering, the nozzle is positioned far above the bed.

    This is mainly the case with smooth surfaces. I mainly use a filaprint (https://www.filafarm.de/products/druckplatte-fur-abs-und-pla ) here, but that had always worked over some years and a lot of Probes ... now with the new IR-Probes (Last delivery 3 weeks ago)
    It worked on a BuildTak now...but that is not the solution...

    But important ... synonymous on the Filaprint, there were no problems so far ... I notice now only since the new IR probes!

    Thank you in advance!

    I hope yoe understand what I mean.... 🙂



  • Does the probe trigger (red light) when you simply press a bit of card etc underneath it. Have you ever seen the red light?

    I see no reason why it wont work on filaprint surfaces; have you seen the notes on surface compatibility here?

    Config please; what does your M558 and associated probing config look like?


  • administrators

    @CR3D said in New IR-Probes -> false Triggerheight:

    It seems to me that when Z-probing the distance is already triggered at about 10mm too early. What I've noticed, I did not see a Led light when triggered.
    After triggering, the nozzle is positioned far above the bed.

    When the probe is operating in analog output mode (signalled by the LED flashing 4 times at startup), the output rises from about 0 to about 465 when the sensor is getting close to the bed. When it triggers, the output rises to about 535 and the LED turns on. So I suspect that what you are seeing is the "near" response. If you are using Duet electronics, you can see the reading is DWC. You should check that the P parameter in your G31 command in config.g is 500, and the P parameter in your M558 command is 1.



  • The probes work fine with buildtak surface at the moment. But i have problems with the filaprint.

    but that only strikes me at the very last delivery. For the last 30 pcs. which I have installed, it has worked well with the filaprint.

    Basically, the probes works ...



  • So here are the Z-Probe Parameters

    73309680-3d57-416a-9d0e-a5fe5adf0e45-image.png

    This are the same as I used it for a lot of machines...

    On an older machine (same settings just an older IR-Probe) when the bed moves towards the probe the bed gets slower and then when the probe triggers there is a short red led flash.

    On the new machine with the new Probe the IR-Probe is flashing 4 times on startup, but the bed doesn´t get slower and there is no flashing light. when i trigger the probe by hand the led flashes.

    But with an BuildTak on it the offset is right. With some other bed surfaces there are problems. And this problems weren´t with older probes ...

    Sorry but I'm a bit clueless...



  • @CR3D said in New IR-Probes -> false Triggerheight:

    Sorry but I'm a bit clueless...

    Same here. I guess the next step is to swap the probes on your old machine. What happens when you put the new probe in it. You appear to be changing lots of things here simultaneously.

    To put it bluntly, Until you can be clear whether these 'new' probes operate differently when simply swapped for a working 'old' one you cannot be clear on whether it is the probe, or something else, that is the problem.

    If it is the probe, you'll need to go back to your supplier.


  • administrators

    I made a change to the firmware on the IR sensors a few months ago. This was to resolve a problem whereby when using a highly reflective bed surface (e.g. white or shiny aluminium), some probes gave a false trigger at a great height (usually several cm) as well triggering at the correct height. So the newer sensors don't trigger unless the total received IR is above a certain threshold. I verified that they still work with dark surfaces, including black/grey BuildTak and with glass backed by black paper.

    You can tell if your sensors have the new firmware, because at startup it gives one short flash, then a pause of about 4 seconds, then the usual 2 or 4 flashes depending on what mode it is in. The older firmware doesn't give the short flash at the start.


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