Nozzle alignment aid

2+24-04-25 Obsolete?

The new 6.0.0 firmware has improved its nozzle alignment so much that I can no longer detect any deviation from Perfect:

https://github.com/prusa3d/Prusa-Firmware-Buddy/issues/3797#issuecomment-2063990752

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2024-04-13 New, smaller version

A new, smaller version has been uploaded, that prints much faster. You can alkso cancel the print when you have enough height to judge the outcome, cutting the print time even further.

Two versions, one with 0.1 mm between ticks, and one with 0.02 mm between ticks, are available.

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This is a visual, calipers-friendly nozzle alignment aid for your multitool XL!

I have been contemplating the very nice banding pattern seen on the purge tower when printing high-contrast filament combinations. And been wondering why it would show on only one side of the tower, and not the other one.

Obviously, this is due to the nozzles not being perfectly aligned, and the layers thus stacking a bit offset, hiding the “innermost” colour.

Also, I have been rather unhappy with the provided nozzle alignment patterns, as eyeballing 0.05 millimeter differences is rather impossible for at least my eyes, and they do also not provide any way to use tools for measuring the fit.

Hence these test objects for nozzle alignment. They provide a number of different offsets, and when printed with high-contrast filament, provides 0.02 mm precision with the naked eye. I suggest black on extruder 1, white on the other extruders (no, I also do not have 4 spools of white Prusament PLA open at the same time, I used what I had open - but white was best).

In image 4, you see the colour difference from 0.05 mm misalignment, it is quite obvious.

If naked eye is not your thing, you may also use (digital) calipers to measure tab width. You will need 0.01 mm precision. Be careful to avoid bottom layers (elephant's foot will ruin the measurement) or the tip of the tabs (the change of direction introduces a slight bulge). Plot your measurements, and the tip of the V they form will be the offset correction you need to make. However, I got exactly the same results from this as from the visual inspection - use whichever method that pleases your OCD the most 😁 

Use the scale in the second image to determine your offset correction. E.g., if -0.1 is found, correct the given axis offset by -0.1 mm.

After correcting, print the test objects again, and this time compare the trunks, not the tabs. If the trunks match on both sides, the nozzle is now perfectly aligned. See image 4 for the result after correcting the situation in image 3.