How do I set more calibration points for Auto Bed Levelling?

[jasay]

I think what Roxy is saying is that the marlin codes does not allow for different number of points in x vs y right now. Being code, it can of course be changed, but that would require a patch and a reason to accept the patch. That's somebody's work both now and for future maintenance and would need to be justified.

Right now your 8"X12" bed with a 4x4 grid will have 4 points in X separated by ~2-2.5" and 4 points in Y separated by ~3.5-4". Is that a problem? Is there a strong use case for e.g. 3x4 probe instead of 4x4? If so, maybe someone will help write the patch and argue for inclusion.

[TehStranger]

I think what Roxy is saying is that the marlin codes does not allow for different number of points in x vs y right now. Being code, it can of course be changed, but that would require a patch and a reason to accept the patch. That's somebody's work both now and for future maintenance and would need to be justified.

Right now your 8"X12" bed with a 4x4 grid will have 4 points in X separated by ~2-2.5" and 4 points in Y separated by ~3.5-4". Is that a problem? Is there a strong use case for e.g. 3x4 probe instead of 4x4? If so, maybe someone will help write the patch and argue for inclusion.

Nah that isn't a problem I just didn't think of that. So how exactly do I do that?

Thanks

[jasay]

Make sure the bed size is entered in configuration.h like I said above so it knows where to probe. Then callout G29 NP where P is the number of points you want in each axis. The software will figure out the gap between points and take care of all the math.

[Roxy]

Go get the latest 'Release' version of Marlin from GitHub: https://github.com/MarlinFirmware/Marlin (Do not grab the development version which is more 'current' than the last Release version!)

Go find this code in Marlin_main.cpp. This code controls the probing across both the X and Y axis. Change it to be what ever you desire it does:

      for (int yProbe = front_probe_bed_position; yProbe <= back_probe_bed_position; yProbe += yGridSpacing) {
        int xProbe, xInc;


        if (zig)
          xProbe = left_probe_bed_position, xInc = xGridSpacing;
        else
          xProbe = right_probe_bed_position, xInc = -xGridSpacing;


        // If topo_flag is set then don't zig-zag. Just scan in one direction.
        // This gets the probe points in more readable order.
        if (!topo_flag) zig = !zig;


        for (int xCount = 0; xCount < auto_bed_leveling_grid_points; xCount++) {
          // raise extruder
          float measured_z,
                z_before = probePointCounter == 0 ? Z_RAISE_BEFORE_PROBING : current_position[Z_AXIS] + Z_RAISE_BETWEEN_PROBINGS;

[TehStranger]

Make sure the bed size is entered in configuration.h like I said above so it knows where to probe. Then callout G29 NP where P is the number of points you want in each axis. The software will figure out the gap between points and take care of all the math.

Tried that but Pronterface is saying [ERROR] Error line number is not last line number+1, last line: 0

Go get the latest 'Release' version of Marlin from GitHub: https://github.com/MarlinFirmware/Marlin (Do not grab the development version which is more 'current' than the last Release version!)

Go find this code in Marlin_main.cpp. This code controls the probing across both the X and Y axis. Change it to be what ever you desire it does:

      for (int yProbe = front_probe_bed_position; yProbe <= back_probe_bed_position; yProbe += yGridSpacing) {
        int xProbe, xInc;


        if (zig)
          xProbe = left_probe_bed_position, xInc = xGridSpacing;
        else
          xProbe = right_probe_bed_position, xInc = -xGridSpacing;


        // If topo_flag is set then don't zig-zag. Just scan in one direction.
        // This gets the probe points in more readable order.
        if (!topo_flag) zig = !zig;


        for (int xCount = 0; xCount < auto_bed_leveling_grid_points; xCount++) {
          // raise extruder
          float measured_z,
                z_before = probePointCounter == 0 ? Z_RAISE_BEFORE_PROBING : current_position[Z_AXIS] + Z_RAISE_BETWEEN_PROBINGS;

Can I use that Marlin_main with my configuration.h or do I have to replace all the files?

[jasay]

Tried that but Pronterface is saying [ERROR] Error line number is not last line number+1, last line: 0

Did you just type the command into the terminal and get that error? I've only ever seen that error when printing and the host software (pronterface) and firmware get out of sync.

[TehStranger]

Did you just type the command into the terminal and get that error? I've only ever seen that error when printing and the host software (pronterface) and firmware get out of sync.

yeah, the screen was all messed up when I connected it with pronterface but no matter what baud rate I used it still kept screwing up.

[jasay]

Hit the reset button on the electronics? Baud rate must match in your firmware configuration.h.

[TehStranger]

Hit the reset button on the electronics? Baud rate must match in your firmware configuration.h.

That worked but the G29 N5 command is still not isn't working

[Roxy]

That worked but the G29 N5 command is still not isn't working

First... The Enhanced G29 that was published here is mostly folded back into the main code base. Depending on what code you are using the options are different. In the main code base 'P' is used to specify the number of points on each axis to probe. In the Enhanced G29 code published here, 'n' (with a lower case) is used. You can never use a capital 'N' with PronterFace.