I stumbled upon model for bolt and nut with knurled interface https://www.thingiverse.com/thing:9095 . I liked how it looks so I decided to adjust nut model and make it to become hand wheels knob for my CNC 3018 X and Z axis. It turned out pretty good.
Knob radius is 24 mm and thickness is 10 mm. It is meant to be used on 8 mm lead screw so it has 8.1 mm hole which is big enough that knob tightly sits on leading screw so it can easily turn leading screw.
There are holes for 3 mm screws if there is need to additionally secure knob on the lead screw. I find it not needed but I added them just in case. Holes are 2.5 mm in diameter and you have to cut threads for 3 mm screw. Screws have to be headless and 5 mm long or less. Screws should not be over-tightened to avoid destroying plastic threads. Use two screws on each knob for balance.
Download knob model: https://www.thingiverse.com/thing:4373353
Printing notes: Using at least three vertical walls is recommended. Print hole up. After print is dome you may use fine sanding paper to soften the edges of kurling pattern.