Cut your bagel perfectly every time.
4 versions to choose from. I recommend version 3 or 4. Version 1 uses a lot of plastic and is quite large. Version 2 is a bit better. Version 3 is smaller and uses less plastic. Version 4 is optimized further.
Fusion360 archive included so you can make adjustments to fit your bagel if needed. I recommend measuring a reference bagel and choosing accordingly. ;)
I'm a perfectionist who likes making custom things, and building a reprap printer scratches those itches perfectly. There's nothing more satisfying than designing a part to fix a specific problem and pulling off the perfect print to do it.