Holey Triangular Calibration

Update

I have done everything I said I would do. I have been able to go through the full calibration Holey Calibration process, successfully. At this point, I am calling it done.

There are still some things that could be improved, but I have been working on this a long time, and I would like to get it in front of a broader group of people.

There are likely still some bugs, so this calibration process is only for the adventurous, willing to accept a potential mistake on my part.

Since I have made changes to GC and the Firmware, outside of the Holey Calibration process, I am going to wait on the Pull-Request until a few people have reported being able to successfully use this version of GC and the Firmware. So, if you are willing, I would appreciate it if you try out this software, and report back on this thread.

Changes from Main Forks

  • Created a GUI and a Holey Calibration process, which is thought to be an improvement from the current Triangular Calibration process
  • Updates some of the string handling functionality, to prevent GC from communicating parameter values in Scientific Notation
  • Firmware Kinematics updated to include the full catenary equation for chain-sag
  • Firmware Kinematics updated to improve diagnostics information when the Kinematics::forward function fails

Instruction

Before you can run the Holey Calibration GroundControl fork, you must install the source code for GroundControl as listed on the GitHub instructions

Download the Firmware and GC from these locations:

The two are aligned in that the kinematics.inverse functions rely on the same math, so calibrations done in Ground Control should translate accurately to this Firmware fork.

Install and use Ground Control and the Firmware normally, just like the main fork. For the most part, it should function equivalently.

When you click on Actions=>Calibrate, you will go into the normal calibration process. It will ask you to go through all the normal measurements and settings as normal. There is one added screen for you to enter the Sled Weight. If you select Triangular Kinematics, you will eventually get to a screen that looks like this:

If you select Holey Calibration, you’ll go through the Holey Calibration process. Depending on your machine configuration, there may be a few additional steps before you get to this screen:

You will have to cut the 6 point test-pattern by selecting the “Run Holey Calibration Cut” button. When you click the button, your machine should jump into action and cut the six-point pattern.

After the pattern is cut, you’ll have to make 12 measurements, shown in the pattern in the blue picture. They are labeled M1 through M12. When you click “Next”, you’ll get to a screen like this:

Enter your 12 measurements in the boxes on the right. Units are “mm”. There is a diagnostic that turns the box red if a measurement is >10% off from where it should ideally be. If a box turns red, that means you’ve likely mis-measured or mis-typed a measurement. When you accurately enter the 12 measurements, and click “Next”, a screen will pop up like this:

It shows the initial measurements, and the initial parameters. When you click the “Calibrate” button, it will perform a parameter optimization to minimize the measured errors. It will populate the “Calibrated” columns for measurements and parameters. If everything looks good, click the “Push to Machine” button, which will write the calibrated parameter values to GC, which will automatically sync with the Firmware. Clicking the “Next” button will lead to a Finish screen which will exit out of the calibration. After that, your machine should be calibrated, synced, and ready.

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