The reason I made this is because I was tired of the ball bearing falling out when changing the disc. 

If you have any issues, please let me know in the comments, and I’ll do my best to fix them.

Use my print settings for the axles.

For housing it doesn't really matter at all i recommend put fuzzy skin on it 

ball bearing 12x28x8 mm

made from: Rolling Knife Sharpener Magnetic Knife Holder Diamond Sharpening Stone Kit with 15 and 20 Degrees Angle Roller Kitchen Accessory - AliExpress 15