POLYMAKER Cardboard Adapter

Key Advantages

Only 7g of filament per ring.
Compatible spool brand name impressed.
Rounded contour helps with traction, avoids pullback errors and stabilizes the spool inside the AMS.
Rounded contour lowers the chance of damaging plastic storage bags.
Flat variant for full AMS compatibility (see tolerance and compatibility section)

Update:

25.03.2024: Based on user feedback, I added an updated version of the 199mm flat and rounded variant which are tighter than the original model. I did not replace the original print profile but rather added a new one with the addendum ‘tighter’. They have a very tight fit and need some stretching to put on.

07.09.2024: Corrected an error in the 199mm flat profile, which previously contained the 200mm model. The 199mm profile has been renamed to '199mm wider' following this adjustment.

Description

This isn't merely a typical cardboard spool adapter. By decreasing its contact area by approximately 50-60% compared to standard adapters, it significantly enhances contact pressure. Consider it akin to winter tires on a car, which generally require higher pressure to minimize their contact area with the ground. Additionally, its rounded edges help stablizing the Spool inside the AMS and minimize the likelihood of damaging plastic vacuum bags. The adapter is not only lightweight, weighing a mere 7 grams of filament, but it is also reusable and easily attaches in the same manner as conventional adapters.

This adapter has proven to be a game-changer, eliminating the need for other AMS modifications that claim to address retraction and entanglement issues. Remarkably, I’ve found that spool weights are no longer necessary. However, as with any solution, individual results may vary. Happy printing!

Tolerances

Compared to plastic spools, cardboard spools are more vulnerable to various external factors, such as moisture, temperature fluctuations, and variations in the production process (up to +/-2mm). Consequently, you may encounter slight variations in the fit, which can range from slightly looser to tighter. In extreme cases, the spool adapter may not fit at all. In these scenarios, you can make the necessary adjustments to the model's scale using the Bambu Slicer for both the X and Y axes. Ensure that you uncheck the "uniform scale" option before proceeding. If your spool's diameter exceeds the default setting, consider increasing the scale by 1%. Conversely, if your spool's diameter is smaller, reduce the scale by 1%, and your setup should be ready for use.

Compatibilty

eSun Cardboard Spools tend to be on the larger side of the spectrum. While they can fit without an adapter, when paired with the rounded 200mm adapter, they surpass Bambu Labs’ specifications. The rounded 199mm adapter techinically fits but there is always a chance that your spool is ever so slightly larger than 199mm causing the adapter to expand and surpassing the specs. Consequently, users have a couple of options to address this:

AMS Lid Spacer: Utilizing a spacer for the lid can accommodate the larger spools effectively.
Custom Backside Rollers: Alternatively, consider implementing custom backside rollers specifically designed to support these larger rolls.
For a straightforward solution, leaving the lid open (or at least not locking it) provides ample room for the spool.

For individuals who prefer not to alter their AMS and wish to close the lid, I have incorporated a nearly flat variant that aligns with Bambu Labs’ specifications.

Printing

When it comes to printing, you should produce two adapters for each cardboard spool. It is advisable to steer clear of materials that exhibit low friction, such as Silk-PLA, to ensure optimal performance. Most of the time I use Standard PLA.

Other Filament Brands

This adapter is available for other brand's cardboard spools (Link to Collection):