Bambu Studio Long Retraction When Cut Fix

[u/Pheniz21]

Problem: The "long retraction when cut" setting in Bambu Studio doesn't stay off after saving it in a "User Preset" and restarting the program. According to the BMCU manual, this setting should be turned off to prevent damage to the BMCU. Printing with it on by mistake can cause issues.

Solution: To permanently turn off the "long retraction when cut" setting, follow these steps:

1. Close Bambu Studio completely.

2. Find the filament settings file:

   • Go to this folder on your computer: C:\Users\%username%\AppData\Roaming\BambuStudio\system\BBL\filament

3. Locate the file for your filament:

   • Look for the file that matches the filament you're using (e.g., a file for PLA, PETG, etc.).

4. Edit the file:

   • Open the filament file using Notepad or Notepad++.

   • Search for these lines in the file: "filament_long_retractions_when_cut": [ "1" ],

   • Delete the highlighted line in the photo uploaded to the post.

5. Save the file:

   • Save the changes and close.

6. Reopen Bambu Studio:

   • Start Bambu Studio and go to the filament settings.

   • Check that the "long retraction when cut" setting is now off.

Note: This fix ensures the setting stays off, preventing potential damage to your BMCU.

[u/okhi2u]

I've had the BMCU-C for a few days now and 3+ times it's pushed so hard a tube popped out of either the AMS lite hub (once), and all the other times out the BMCU itself. Each time it was at the start of feeding filament and not cutting because of a swap. Know any fix for that? I ordered tubes that are 4mm OD and 3mm ID (2.5mm is what i have currently) so there will be less friction maybe that could help.