This is an adapter that is intended to make smaller spools usable with the AMS. 

• Both halves print with only about 145 g of filament.
• Prints quickly.

I needed an adapter that I knew would work for my particular project, and decided to share it. 

This adapter was designed for my 120g spool. But it should be usable with a wide variety of smaller spools, particularly 250g spools. 

The adapter is 200 mm in diameter. Each part has a centering cone that is 73 mm at the widest and 41 mm at its narrowest. This feature helps center small spools. The two halves screw together, and can be as narrow as 45 mm (flanges closest together) or as wide as 80 mm. 

Your spools will work best if they have a center bore hole that is bigger than 41 mm. Because the centering cone tapers, wide spools need large center bore holes. If a wide spool has a small center bore hole, the two halves may not screw together. 

Keep in mind that spools used in the AMS should have a minimum width of 50 mm and a maximum width of 68 mm.