I'm using latest stable Marlin with BLTouch. The BLTouch seems a bit damaged so I want to increase its accuracy with multiple measurements.

I've increased #define MULTIPLE_PROBING to 3 but it seems it applies only to mesh ABL and doesn't work with single center homing. I want to get something like fastprobe + average for two or three slow probes.

Am I missing something? Or it is not possible?


Homing and mesh probing are 2 separate actions, by setting #define MULTIPLE_PROBING to 3, you inherently create 3 slow probing points for the mesh probing (not the homing probing), with 2 you get a fast/slow probing action.

Everything is possible, but, that means that you need to dig into the sources; not changing the configuration constants. That is not for the faint hearted.

I've seen the responses of fast and slow probing in action, usually the difference is not existent or very very small, like one or two hundredths of a millimeter, I seriously wonder if it makes sense to use more than 2 probing points.

Please note that a damaged bed may benefit more from increasing the probing array amount (from 3 x 3 to 4 x 4 / 5 x 5). The number of probing points discussed earlier only dictates the amount of probing actions in a single point; if the sensor hits the bed the probe measurement is done, if it hits again, the value should more or less be the same (give or take the accuracy of the sensor), I do not see what damage to a bed would imply more probing measurements in a single spot. The only rationale would be if the sensor itself has a large inaccuracy with an error that is not systematic, but random. My BLTouch (original) is pretty accurate and repeatable, I've had more issues with all those cheap knock-offs.

  • $\begingroup$ Ofcourse everything (almost) is possible :) I mean POSSIBLE to change by some with some define constant. And you confirmed my assumptions that NO. Originally was talking about damaged probe, not bed (It was edited by moderator) $\endgroup$ – Dmitriy Jul 15 '20 at 21:02
  • $\begingroup$ @Dmitriy My apologies, it was not clear, the bed was assumed as it was not referenced what it was. I have reverted it. No harm intended. Please add what damage the probe has. $\endgroup$ – 0scar Jul 15 '20 at 22:03

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