abl-helper

A little program to unify the output of multiple Marlin G29 T commands. The output resembles the report of the M48 command. The program is useful for diagnosing mechanical issues with a printer - while the M48 will indicate any accuracy problems with the probe itself, it doesn't give you any guarantee that the grid as a whole is accurate. Mechanical issues could result in measured distances varying between different G29 runs. This program helps you understand how big that variance is, and hopefully pinpoint the issue. Currently, the program only works for cartesian printers.

Usage

If you have a heated bed, set the temperature to the value you are usually printing at. Then issue a G29 T command through a console (Pronterface, Octoprint). After the probing procedure completes, a topology report will be generated. Repeat the procedure as many times as you wish and paste these reports into a text file. Then pass the path of the text file as an argument to abl-helper e.g. abl-helper grids.txt. The program will automatically figure out the dimensions of the grid, whether it's 3x3, 5x5 or something else entirely. Any extra text will be ignored.

In a nutshell, the program turns this:

Recv: Bilinear Leveling Grid:
Recv:       0      1      2
Recv:  0 +0.054 +0.022 +0.028
Recv:  1 +0.063 +0.018 +0.014
Recv:  2 +0.087 +0.042 +0.028
Recv:
Recv: Bilinear Leveling Grid:
Recv:       0      1      2
Recv:  0 +0.058 +0.019 +0.027
Recv:  1 +0.060 +0.014 +0.011
Recv:  2 +0.084 +0.035 +0.023
Recv:
Recv:       0      1      2
Recv:  0 +0.059 +0.022 +0.031
Recv:  1 +0.063 +0.018 +0.014
Recv:  2 +0.085 +0.037 +0.027

Into this:

Found 3 measurement grids...
SD    - Mean: 0.001816 Max: 0.002944 Min: 0.001247
Range - Mean: 0.004    Max: 0.007    Min: 0.003
┌─────────────────┬─────────────────┬─────────────────┐
│ Mean: +0.057000 │ Mean: +0.021000 │ Mean: +0.028667 │
│ Min:     +0.054 │ Min:     +0.019 │ Min:     +0.027 │
│ Max:     +0.059 │ Max:     +0.022 │ Max:     +0.031 │
│ Range:    0.005 │ Range:    0.003 │ Range:    0.004 │
│ SD:    0.002160 │ SD:    0.001414 │ SD:    0.001700 │
├─────────────────┼─────────────────┼─────────────────┤
│ Mean: +0.062000 │ Mean: +0.016667 │ Mean: +0.013000 │
│ Min:     +0.060 │ Min:     +0.014 │ Min:     +0.011 │
│ Max:     +0.063 │ Max:     +0.018 │ Max:     +0.014 │
│ Range:    0.003 │ Range:    0.004 │ Range:    0.003 │
│ SD:    0.001414 │ SD:    0.001886 │ SD:    0.001414 │
├─────────────────┼─────────────────┼─────────────────┤
│ Mean: +0.085333 │ Mean: +0.038000 │ Mean: +0.026000 │
│ Min:     +0.084 │ Min:     +0.035 │ Min:     +0.023 │
│ Max:     +0.087 │ Max:     +0.042 │ Max:     +0.028 │
│ Range:    0.003 │ Range:    0.007 │ Range:    0.005 │
│ SD:    0.001247 │ SD:    0.002944 │ SD:    0.002160 │
└─────────────────┴─────────────────┴─────────────────┘

For a printer without any outstanding mechanical issues, the standard deviation (SD) value should be close to the one reported by the M48 command.

Installation

• Install stack
• Run stack install in the root directory of the project