I need some hold down knobs to secure fixtures on my table saw sled and also on the CNC to secure stock to be machined. But I don't want to buy any so figured I'd make some out of 1/2" MDF. This was my first time to use the circular pattern capabilities in Fusion 360 to create the grips and it works like it is suppose to so that's a good thing. These were fun to make so I made 20 of them - 12 in 2.5" diameter and 8 in 1.5" diameter. Some will have brass threaded 1/4-20 inserts and some will have hex head 1/4-20 bolts. The video below shows cutting the hex recess into four of the knobs.