Rigidbot 2 - 20 tooth pulley upgrade

This is my rigidbot 2 upgrade to 20 tooth pulleys. No permanent modifications to the original rigidbot 2 frame is required. The idler pulley adapters just snap in to place, and the idler pulley is secured with a m5 bolt. To align the belt I used spacers that snap in place behind the original belt holders and are held in place by friction. The spacers also serve as tensioners, you will need to install your belts 2-3 teeth loose, then install the spacers. If the belt tension seems too tight,