Add default values for skew correction to Skew_Correction.md?

Hi! Can you please add the default values to the documentation (docs/Skew_Correction.md & Skew_Correction.html)?

i tried to save the g-code macro SET_SKEW XY=141.5,141.5,99.8 (measured) many times until i noticed that this must be the default values because GET_CURRENT_SKEW always showed XY Skew: 0.000000 radians, 0.00 degrees
Imgur: The magic of the Internet

If i eg send the gcode SET_SKEW XY=140.4,142.8,99.8 → the gcode command GET_CURRENT_SKEW show XY Skew: -0.016951 radians, -0.97 degrees
Imgur: The magic of the Internet

i am sure this information would be helpful to others trying to configure the skew correction

Have you done a SAVE_CONFIG after SET_SKEW... ?

yes but with exactly SET_SKEW XY=141.5,141.5,99.8 nothing happens. only if there are different values like SET_SKEW XY=140.4,142.8,99.8 (Imgur: The magic of the Internet)

Not sure that I follow you. From the documentation

Where did you get that you shall enter exactly THESE values?

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What defaults do you want?
There are some example values in the docs.
If there is no skew in your prints, what do you want more?

There are NO defaults.
You need to print the test object and enter the values as measured on the PRINTED OBJECT.

Nowhere it is mentioned to simply copy paste the “FOR EXAMPLE” values.

everything is correct and i am happy :wink: but maybe the exact measurements of the 2 models and each mesurement (AC default = 141.5mm, AD = 100mm, and so on) could be added to the documentation. So other users don’t have to DIGITAL measure the models manually and try to input the “nearly exact correct skew values” (like i did) which does nothing because they are correct

There are different models available.
And as different filaments have different shrinkage rates it is senseless to give raw values.
Measure, set skew correction and reprint and verify.

You apparently did not understand the concept. Nowhere in the process you need the “true” values:

  1. You print the test object
  2. You measure the marked lengths
  3. You use SET_SKEW XY= with the MEASURED values
  4. You save your profile with SKEW_PROFILE SAVE=my_skew_profile

Edit:
And if SET_SKEW XY= or GET_SKEW returns 0 then you simply do not have a skew

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but why does the input of my manual measurement of the print with the command SET_SKEW XY=141.5,141.5,99.8 has no effect? i thought the values are nearly perfect so no skew correction is necessary? i still don’t get it

@Sineos ok your edit is exactly what i thought

there was nothing in the logs so i tried to input the values again and again because i thought there maybe is another problem. a few days later i digital measured the model and recognized that the values are very close to the correct values. If there would be a better feedback in the console or a hint in the documentation it would be nice imo