Does anyone know where I would buy more input couplers for a versaplanetary gearbox that works with Neos? I have previously used these input couplers with a set screw by trimming down the output shaft on the Neos, but I am not sure if any vendors sell just these input couplers or alternatives?
AFAIK That coupler is not sold on its own, and can only be bought with the VP base kit. You could try reaching out to Vex to see if they will sell you a few of them?
Vexrobotics.com search for versaplanetary motor mounting hardware kit.
The coupler is the standard coupler sold in the hardware kit 217-4649 referenced in the post above. You also also need a CIM adapter to mount the motor to the box. which it sound like you already have. You will either need to cut the motor shaft or make a spacer. The gear box is marginal for a neo power. Don’t use high reductions.