General-purpose focus gears sold for photographic lenses are not so good, assuming that they will be used in the actual field, because the gears slip and the remaining parts are caught on the rig.
On the other hand, the fully customizable and already-built gears such as https://followfocusgears.com/ are very expensive.
So, I tried to make it myself using https://github.com/jaymis/lens-gear-follow-focus, but this time the Leica R lens that I am going to use is made of a metal focus ring When I tried to fix it firmly, I had to make it quite tight, but while I made several prototypes, I felt like I was damaging the lens.
So I decided to design a customizable gear that could be tightened with screws.
Because I wanted to be able to fully customize it, the number of parameters becomes relatively large. Therefore, it is not necessary to read the generated STL again with DesignSpark Mechanical, fine-tune it, and follow it.
In fact, it may be easier to see the figure.
The number of gear teeth for one lap. Note that the number of teeth is actually increased because a cut is made to tighten the screw.
Outer gear thickness (axial length).
Inner gear thickness (axial length).
The diameter of the inner hole. The outer diameter of the lens.
The radial thickness of the gear part. If it is thinned, the entire gear is easily bent when tightened with screws. When it is thick, it becomes difficult to bend.
The thickness of the spring mechanism on the inner plane. It should be a multiple of the nozzle diameter of the printer used.
The length of the tab protruding for the screw hole.
The thickness of the tab that protrudes for the screw hole.
Screw hole diameter.
Screw hole location. Distance from the outermost edge of the tab that popped out.
The distance between the tab protruding from the screw hole and the gap between the tabs.