KB knife sharpener using 625 bearing and 5mm dowel pin

This is remix of KB Knife sharpener from fsanders. Thanks fsanders for sharing CAD files. 

It is basically changing 606 bearing to 625 bearing, which is 1mm thinner and 1mm narrower. To compensate this, moter plate and brace arm has bump. It is also helpful for smooth movement of idler roller. 

Since I uses mainly prusa slicer, hole are bit more tightned. At least for me, motor shaft and dowel pin could be press fitted. Maybe idler_fork is too tight for moter plate and brace arm. If so, you can use 16.5 varinent or just sand idler_fork a liitle. I would suggest to use superslicer or bambulab studio and set top layer flow to 0.9, for smooth top layer. 

For model strength, I add champer for roller housing and make shell thicker. It is applied only to 16.2 varient.