The Arrow Factory is a building that creates arrows for arrow towers. Produces arrows out of steel and tree trunks.
- Keep these 1-2 levels below your base.
- Only upgrade these if they are at full production but you need more arrows.
- If you are not at full production, see if you need more intermediate products or raw resources.
- Do not be afraid to upgrade. Surviving is more important than a few crystals.
- Upgrade these before Cannon Ball Factorys.
- these should be on the same level as sawmills/steel factories.
Characteristics at different levels
 original reference