Homemade device for precise sharpening of drills, analog of the sharpener General no. 825

How to make an analogue of original drill grinding attachment general no. 825 at home. How and what to sharpen a drill. How to properly sharpen drill bits. Sharpening device for drills. The device from the corner grinder is very necessary. sharpening of a drill. How to achieve the correct angle when sharpening a drill. Drill bit. Overview tool. Images with dimensions are here: