You mean something like this? The block on the motor mount has a 4mm screw that is used to hold the motor from moving away from the spur. It worked great, but once I moved up to a better motor (Neu which allowed me to tighten the motor mount screws tight enough to prevent the motor from moving( I no longer needed it. The Feigao's use softer aluminum and you couldn't really tighten the screws to much without fear of stripping them out.
