Inductive Z Probe Settings



  • Hi,

    For users of inductive Z probes what are you using for the following parameters in your M558 command?

    F - feed rate
    H - dive height
    R - recovery time
    A - max number of probes
    S - tolerance

    Thanks much.

    Frederick



  • This is what I used for Pinda:

    M558 P5 C"^zprobe.in" I1 H1 F1000 T6000 A20 S0.005              ; Prusa PindaV2
    


  • @Kolbi said in Inductive Z Probe Settings:

    This is what I used for Pinda:

    M558 P5 C"^zprobe.in" I1 H1 F1000 T6000 A20 S0.005              ; Prusa PindaV2
    

    Thanks.

    Frederick



  • depending on the repeatability you want, you may want to slow the feedrate which is really because of the worst part of inductive probes. Most inductive probes switch at 500hz until you you break the ~$60 retail price point for industrial sensor to get 1khz to 3 khz ( next price point is like ~$150+ and specs can get to 5khz). So the faster you're probing the larger the distance variation between trigger intervals. i use a ie5390 i grabbed off of ebay for like $30 and it operates at 1khz and i go with 60mm\min to get .003mm repeatability which is only a microstep and it levels (delta printer) to .01mm over a 300mm probe area



  • @lord-binky said in Inductive Z Probe Settings:

    depending on the repeatability you want, you may want to slow the feedrate which is really because of the worst part of inductive probes.tep and it levels (delta printer) to .01mm over a 300mm probe area

    Thanks for that. I don't mind paying for performance and now I know what to look for.

    I bought several off of Amazon just to experiment with but I have no idea what the detailed specs are, if they even have specs.

    Frederick



  • @fcwilt I got a few of the 10 to 12 mm ones off of amazon and they did fine, until I went down the number chasing rabbit hole. The LJ8/10/12's are all 500hz switching, so you can expect them to vary about +/- 0.033 mm in their response (not including things like microstepping) if you run the feedrate at 1000mm/min. With that though, you'll at least know when it's the switching time or mechanical play which is perfectly usable and still better than I've gotten out of physical switches. For physical switchs, oddly the best repeatability I tested was actually a switch I pulled from a spare sanwa arcade button I had, much better than a limit switch although definitely not as rugged. Makes me want to test a cherry MX red mechanical keyboard switch as a probe when I think about it... I think playing with delta's for 7 years is starting to show....

    note: the field coming off the induction probes are typically two lobes (oblong spheres) which isn't labeled in any way. The detection pattern for most of the useful distance would plot in an oval or even a peanut shape, which isn't an issue for their typical use (and why the detection object is usually specified as at least the diameter of the probe). This means the probes will be more sensitive to tilt in some arbitrary axis (well, where ever the center line between the two lobes is) compared to a corresponding perpendicular axis. TL;DR being do you best to mount it as perpendicular to the bed as possible it'll carry the tilt into the measurements like any other probe (and if you're a number chaser like me, incorporate a locking ball joint in the mounting).



  • Hi,

    Thanks again for the very helpful information.

    One of my automation suppliers had both 2 kHz and 3 kHz devices so I order two of each to continue my testing.

    Frederick



  • @fcwilt Please leave a post with your findings. I use a IE5390 I got off of e-bay for $30 (normally $93), which switches at about 1khz. Seeing the results from higher switching sensors I'd find very interesting, but not so interesting as to see my wife's response to me buying multiple probes to test thoeries...

    https://www.ifm.com/us/en/product/IE5390



  • @lord-binky said in Inductive Z Probe Settings:

    @fcwilt Please leave a post with your findings. I use a IE5390 I got off of e-bay for $30 (normally $93), which switches at about 1khz. Seeing the results from higher switching sensors I'd find very interesting, but not so interesting as to see my wife's response to me buying multiple probes to test thoeries...

    https://www.ifm.com/us/en/product/IE5390

    The ones I got worked fine EXCEPT I use BuildTak FlexPlate System and the magnets embedded in the plate prevent accurate readings.

    Frederick



  • @fcwilt Yeah, I figured you'd need a custom bed.g to avoid the magnet locations but never saw anyone say anything about those systems with inductive probes, which kept me from swapping out my PEI covered aluminum disc for a flex (works good enough until I abuse the sheet too much). At least it's easy to generate a custom bed.g just don't go over 32 point (including P0). I posted my google sheet's of mine I did for delta's, but it'd probably be easier to just make one for a cartesian from scratch.

    https://forum.duet3d.com/topic/14871/sharing-my-delta-bed-g-spreadsheet?_=1605991873564


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