The ideal entrance size is around 45mm based on Tom Seeley's work, this allows for fully open or partially open, use the slot with landing board for a reduced colony and easier to protect, or close entirely or use the vents. this is suitable for any horizontal hive or vertical hive with a round entrance, use 3 of them on a horizontal Layens hive which is what I have. Despite what you may read PLA is very durable outside, I've had parts exposed to the full extent of the weather for years now without issue. Use a 5mm screw to secure the disc directly above the entrance and rotate the disc to align the desired entrance.
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