I became quite frustrated with the inadequate performance of electric vacuum pumps marketed for sealing filament bags—both a USB-powered model by Sunlu and a battery-operated one I purchased from AliExpress. In contrast, I own a more powerful vacuum pump designed for clothing bags, which uses a wall plug (https://aliexpress.com/item/1005002765656716.html). Unfortunately, it lacks an O-ring, which is typically integrated into the bag itself. To improve the sealing efficiency, I crafted a straightforward adapter, which has significantly reduced the vacuuming time from an annoying 30-45 seconds down to a mere 5-10 seconds.

This particular pump has an inner diameter of approximately 38mm, though my design can be conveniently modified to fit any size.

For the best results, I suggest printing the adapter using the softest material available to you. I initially used TPU 95A, which was fairly effective, but not exceptionally soft. A better performance was achieved with eSUN TPE-83A, and while still not as perfect as a silicone O-ring, it proved sufficiently effective. The pump's suction is potent enough that it stays in place without the need to hold it against the valve.