Ever ripped off the side of a cardboard spool, only to find out the empty spool you have doesn’t fit? 

Introducing a fully customizable filament spool designed with OpenSCAD, that will always be a perfect fit. 

Features:

• Customizable Dimensions: Adjust the core diameter, outer diameter, hole diameter, and core width to fit your filament refill, or carboard spool.
• Unique Design Pattern: Use multiple patterns of different icons, to make your own personal spool sides!

Guide to replacing the cardboard for AMS Compatible spool:

1. First measure the distance between the sides of the spool.
2. Put tape over the filament, to prevent it from winding out. 
3. Check inside the hole of the spool, and find out on which side the filament is stuck through.
4. Rip that side off.
5. Measure the inside diameter of the cardboard spool.
6. Open the Model Maker by pressing  
7. Enter the measured inside diameter in spool_core_diameter.
8. 
9. Print the test ring, and check if it fits well. 
10. Now enter the other parameters, like the core width we measured in step 1.
11. 
12. Design your pattern for a personal touch
13. Download the 3MF/STL file for the Male and Female part, and print both models.
14. Push in the Male part first, with the notch on top of where the filament stuck through.
15. Turn the spool around, and rip off the other cardboard side.
16. Push in the Female part in, and twist it until it clicks.

If you're confused about some of the steps, there are several videos online that show how to do this with a standard BambuLab roll.

Tips:

1. Make sure the spool_core_dia is at least 20mm bigger then the spool_hole_dia.
2. An intricate pattern will increase the printing duration. The spool I show in the photo's takes 4h5m to print, while the same model without any pattern will take only 3h3m to print. It will, however, save you a whole 4 grams of filament :)
3. To easily label which filament is on the spool, check out https://makerworld.com/en/models/482498. 
4. Be aware, you can create small loose pieces, by putting icons too close to each other.

        Example:

Feel free to ask if you have any questions or need further customization options.

Updates:

v1.1    : Added 2 holes following the curve of the spool core.

v1.2    : Changed default values of

               - spool_side_thick          2-> 2.4

               - spool_border_thick     0.4-> 1

            : Border hole values now adjustable under Optional parameters

            : With default settings, border holes are similar to the BambuLab spools holes.