M558 Dive Height not following docs


  • Moderator

    @gnydick said in M558 Dive Height not following docs:

    M584 X0 Y1 Z5:6:7 E3:4 U2 ; set drive mapping M350 Z64 I0 ; configure microstepping without interpolation M350 X16 Y16 U16 I1 M350 E64:64 ; configure microstepping with interpolation M92 X200.00 Y200.00 Z6400.00 E3267:3267 U400 ; set steps per mm M566 X1500.00 Y1500.00 Z36.00 E1000.00 ; set maximum instantaneous speed changes (mm/min) M203 X24000.00 Y24000.00 Z900.00 U6000 E12000.00 ; set maximum speeds (mm/min) M201 X2000.00 Y2000.00 Z2000.00 U125 E1000.00 ; set accelerations (mm/s^2) M906 X1600 Y1600 Z800 E800 U300 I30 ; set motor currents (mA) and motor idle factor in per cent M593 F36.92 M84 S30 ; Set idle timeout ; Axis Limits M208 X0 Y0 Z0 S1 ; set axis minima M208 X308 Y279 Z580 U28 S0

    You've got 2 E drives mapped, but most of your commands only have a single E value defined, meaning the second E drive might have unexpected defaults assigned. Definitely specify the values for both E drives.

    It also looks like you have a U drive defined and a maxima set, but no minima.

    M574 Z1 S2 ; P"zprobe.in"

    In the context of using a Z probe, this makes no sense really. M574 S2 is intended for using a probe sensor for an axis other than Z and was originally implemented for an Ormerod printer.

    I don't see your probe config in that file, so it must be in one of the other macros?

    Again, using G1 H1 Z in your homing file seems odd if you're intending to use the probe.

    Can you send M98 P"config.g" to check your config for any other syntax errors?



  • @Phaedrux the G1 is to get a fast move to the probe, then the probing action is VERY slow. That's why it's there. I'll run that command.



  • @Phaedrux re: single value for E, a lot of commands will apply the same value to all "E" defined. So far everything has worked as expected.



  • @Phaedrux U axis, yeah, I'll add a minimum. So far it's been assuming 0.



  • @Phaedrux re: M574, that was generated from the online configurator. What is the intended config for using a z probe as the z end stop?


  • Moderator

    @gnydick said in M558 Dive Height not following docs:

    @Phaedrux re: single value for E, a lot of commands will apply the same value to all "E" defined. So far everything has worked as expected.

    @gnydick said in M558 Dive Height not following docs:

    @Phaedrux U axis, yeah, I'll add a minimum. So far it's been assuming 0.

    Ok good, just didn't want you to get caught out by an undefined value at some point.

    @gnydick said in M558 Dive Height not following docs:

    @Phaedrux re: M574, that was generated from the online configurator. What is the intended config for using a z probe as the z end stop?

    Yes the configurator will generate it that way, but it's not really necessary. Using a Z endstop and a Z probe will work just fine, but the way you're using it now is odd because technically you don't have the Z endstop defined at all, it's defined as a probe. It's just a little weird is all and not really necessary.

    @gnydick said in M558 Dive Height not following docs:

    @Phaedrux the G1 is to get a fast move to the probe, then the probing action is VERY slow. That's why it's there. I'll run that command.

    If this is the end goal then the best way to achieve it using the probe is like this.

    In your homeall, instead of using G1 H1 Z move to home quickly, you can just specify a fast probe speed before the G30, followed by setting a slower speed and probing again.

    M558 A1 F450 ; set fast single probe
    G30 ; probe the bed
    M558 A5 F50 ; set slower multi probe
    G30 ; probe again for detail
    


  • Thanks. but 2 questions remain...

    1. (original) how do I use a small dive height, less than the 2x the probe offset

    2. if it's configured incorrectly (the M574), how should I be doing it?


  • Moderator

    Well by definition you can't really use a dive height lower than your trigger height.

    G31 P500 X22.7 Y25.8 Z4.348

    Your trigger height is 4.3mm, meaning that when the probe triggers, your nozzle is 4.3mm above the bed. If your dive height is 5mm, then your nozzle will be raised at least high enough above the bed for the trigger to happen safely before the nozzle hits the bed. When you set the dive height to only 1mm, it can't raise it above the trigger height.

    You can leave the M574 as it is if you want. As I said, it's pretty irrelevant. Oddly enough the way you have it configured allows you to use the probe either as the endstop or the probe. There's nothing wrong with it, I've just never seen it used in this way. Normally the z probe and the endstop switch would be separate devices, for example a Z max endstop switch and a Z min Z probe.



  • @Phaedrux that's not how the docs read. They say ... the firmware moves the Z probe to this height above where it expects the bed to be. So, if I put a 1mm dive height, it will "place the probe 1mm above where it expects the bed to be." Doesn't that mean it will use it's knowledge of the offset to do so?


  • Moderator

    So how is your trigger height 4.3mm if a 1mm dive height works for clearance?



  • @Phaedrux because homing doesn't work if I set it to 1mm.

    Also, I tried removing the M574 for the Z and it won't home. I can't find instructions for using the z probe as the endstop for the Z otherwise.


  • Moderator

    @gnydick said in M558 Dive Height not following docs:

    I can't find instructions for using the z probe as the endstop for the Z otherwise.

    I gave those above. The difference is that you don't use the G1 H1 Z command to act as an endstop, you use G30 to use it as the probe.

    @Phaedrux said in M558 Dive Height not following docs:

    In your homeall, instead of using G1 H1 Z move to home quickly, you can just specify a fast probe speed before the G30, followed by setting a slower speed and probing again.
    M558 A1 F450 ; set fast single probe G30 ; probe the bed M558 A5 F50 ; set slower multi probe G30 ; probe again for detail

    @gnydick said in M558 Dive Height not following docs:

    because homing doesn't work if I set it to 1mm.

    So what is your measured G31 Z trigger height for the probe?



  • @Phaedrux thanks, found the instructions you were referring to for home-z script. Removing the G1 H1 fixed my problem, now the probe dive height is as minimal as I desired.

    Thanks!


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