I know, there are already tons of them. But I had some specific needs and I simply like to play with customizable openscad designs.
It would not be worth if it was not versatile so you will be able to design yours according to your needs. I publish it anyway: having more choices never hurts and people may even find that it suits their needs better in some case, who knows ;)
By the way with one wing only, you can make wrenches!
Use the customizer to set the various parameters such as the number and size of the wings, the nut properties and thickness.
To lock the nut in place, one easy solution is to use a threaded rod of the appropriate size, a washer and a butterfly nut as shown on the pictures: align the nut with the slot then slowly screw with force until the nut fully slides in place.
I used different ones for my bed leveling and to lock my extruder wheel. It obviously would be useful as a Z-screw adjuster, etc. You can discard the nut completely also.
Make sure to check also Harrison's Customizable Thumb Knob (http://www.thingiverse.com/thing:45117). His wing shapes are different, and the thing is hollow (may be less robust?).