I recently lost the retainer plate that goes on top of the version 3 gearbox in my Dboys RK-03. I've been poking around online and haven't been able to isolate the part. Can the gearbox function properly for an extended period of time without this piece? Can I fabricate a replacement, and does anyone have any experience with this? Can someone link me to a site that sells the plate or a cheap gearbox shell with a compatible plate?