GT2 belts have very little inherent backlash if installed right. Use genuine 6 mm GT2 belt with matching 20-tooth pulleys and toothed idlers, set the pulley grub screws on the flat of the motor shaft, and tension the belt firmly — a loose belt is the main backlash source. Keep belt runs short and well-supported, and avoid smooth idlers pressing on the toothed side.
Because cutting force is almost nil, you will not see the belt 'wind up' that plagues routers. If you still measure play, check for a loose pulley grub screw, a sloppy idler bearing, or carriage wheels that rock — those mimic backlash and are usually the real culprit.
Because cutting force is almost nil, you will not see the belt 'wind up' that plagues routers. If you still measure play, check for a loose pulley grub screw, a sloppy idler bearing, or carriage wheels that rock — those mimic backlash and are usually the real culprit.