A well worn subject, but I've just received a delivery of a set of gears that might be of interest.
A long term user of quality 3D printed gears, I am in the process of changing from vintage Nikkor and Tokina lenses to Sigma so I decided to review the current market. I'd initially started out with the Cinevate/Cinematics option and found them useful for their long throw ability and often dusted them off when the need arose.
In my research, I came across a supplier in Belarus that produces seamless flexible seamless gears. At around USD6 per gear, I thought the risk was minimal so I ordered a focus and zoom set for my Sigma Art 18-35. They have just arrived and I have to say that I am shocked how good they are. Far more accurate than the finest resolution 3D printed gears in my set, they fitted perfectly and engage positively with my follow focus. Far cheaper than the 3d printed, Lux and Simcine gears, the only downside to the deal is that they took 3 weeks to arrive (Belarus to Australia).
Highly recommended.
https://www.youtube.com/watch?v=DDKJkgFUHGs
https://www.ebay.com.au/itm/FLEX-Sea...m/291897239879