Sometimes you need fake eggs to trick your hens into breeding mode. Or to help a hen understand where you want her to lay her eggs. That's what plaster eggs are for.

Of couse you can buy them. But of course you do not want to wait and make them yourself if you have a bag of plaster at home.

Print the top and the bottom part. Lay them flat on the printing bed with their flat side.

My print settings for my Neptune 3 printer:

• PLA
• 210°C
• 60 mm/s
• 0.16mm lay height (0.2 should work as well)
• no support
• number of walls: 5 (to avoid that the slicer prints infill into the walls)
• printing time is 2 hours

Grease the inside of the mold with vaseline. Stick both parts together. They should fit tightly. Mix your plaster powder with water and make sure it's liquid enough to flow easily. Let it flow into the mold. Use a thin pointy object (e.g. a spit of wood) and poke into the opening to make sure that any air bubbles come out. Fill the egg as high as you can.

Give it a day to harden properly. Twist the two parts carefully to open the mold.

I have created this mold with the free version of DesignSpark Mechanical which is my favorite application to create such simple models. Feedback welcome.