Hi all,
I recently watched CnC Kitchens’ video on the Califlower calibration print. https://www.youtube.com/watch?v=H7OsnMLDIMw
I am working through calibration on my other printers but will get to my J1 at some point. Stephan calibrates the J1 in his video and I noticed it didn’t perform so well on skew.
Now that snap maker has opened up the firmware has anybody looked at digitally compensating for skew as can be done in klipper reprap and marlin?
Cheers
Have the opened the J1 firmware? I only see the v2 firmware on github. Even if they’ve released the firmware, it took the community a while to figure out how to build and package the V2 firmware.
I had a look at the video. Now I’m curious 
I’ll try to calibrate using XY Axis Calibrator (Steps/mm and Skew Correction).
For setting the parameters, I was thinking of using M852 into the Start g-code (Bed Skew Compensation | Marlin Firmware) rather than recompiling the firmware.
On Github, the latest release v2.2.11 31May2023 seems obsolete.
However, if you look at the code, the last changes were made in January 2024 and according the the commit log, they seems to match the changes from V2.7.1.
So I would say the development is still ongoing and you can get the latest source files. Not sure if there is a lot of activity though.
Well the skew correction feature is disabled in the firmware:
//#define SKEW_CORRECTION
Anyway, I printed the calibration shape and here is what I measured (n=5):
I think the difference between external and internal is too large and probably I should tune the material profile first.
If I ignore the inner measurements, i get
| Est. X movement error | 0.013% | [Step/mm will need to be increased] | |
|---|---|---|---|
| Est. Y movement error | -0.056% | [Steps/mm will need to be increased] |
Increasing steps for X seems wired to me. I think there is a mistake in the spreadsheet formula in E14.
Regarding the skew, I don’t know if these numbers look good or bad. Any opinion?
You might want to repeat that test several times with the same material and then repeat that test range with other materials and other nozzles of the same size (and/or different sizes, if you use different ones) to get a reliable result.
When it comes to the general tolerances of an FFF printer, take a look at what the usual 3D printing manufacturers state as achievable.
AFAIK most of the tolerances come from the liquid filament not behaving as ideal as it should in the moment it has left the nozzle, not from the printer kinematics.
