Screw Together Egg with Money Holder (Similar to the "Impossible" models)

April 18, 2025
Description
Here is a fun Easter related model. The two pieces screw together to form an egg. There are two versions of the inner piece, one with a hole in the center to hide money and one without. The mode is similar to the popular “impossible” models except the base on the outer part prevents the inner piece from sliding all the way through.
With proper cooling settings, all pieces can be printed without supports. I found the bed adhesion on the inner piece with the hole was a little too weak for silk filament unless I added an adhesive.
There are 3 versions of the outer piece.
- Egg Outer (Finger Grips).stl: (Recommended) Same as the loose model, but with small indents to help grip and separate the pieces.
- Egg Outer (Loose).stl: Looser fit for easier motion and may work better for some printers
- Egg Outer (Tight).stl: Tighter fit between parts ensures they don't come apart accidentally. Depending on your printer, the tighter fit may make unscrewing the halves difficult. If so, try putting the inner piece in upside down and cycle it in and out a few times.
There are 2 versions of the inner piece.
- Egg Inner (Hole).stl: Standard Inner piece with a hole in the middle to store a surprise (my niece recommended $20, though $10 would be ok ;-) )
- Egg Inner (No Hole).stl: Same part but without the hole in the center. With more surface area, it may stick to the bed better.
Recommended Print Settings:
- Both pieces print without supports.
- Layer Height: 0.2mm, though higher or variable layer height may improve top of the egg
- If the bottom fuses, try increasing elephant foot compensation
Scales up without issue but I wouldn't scale lower than 70% of the Loose or Finger Grips outer piece as the clearance gets rather small. If there are requests, I can add a smaller version.
I also have two other egg models:
- Single piece, spiral eggs
- Sliding door egg containers