Capsule Nesting Doll Keychain (No Supports, Easy Print)

Design Highlights:

My child wanted capsule toys, but I wasn't satisfied with the existing ones, as some had rough assembly, required too many supports, or lacked fine surface quality. So, I modeled a set of capsule toys.

1. This design uses threaded connections (more fun and stable than snap-fits). After 8 rounds of print verification and dimension adjustments, the thread size and part wall thickness were finalized. This achieved a balance between minimal wall thickness and aesthetic quality, as well as a balance between thread functionality and ease of printing.

2. To avoid using no supports and achieve perfect spherical print quality, the spherical areas at both ends of the capsule are oriented upwards during printing. Since the first layer between the capsule and the build plate consists of only two perimeters (small contact area), a print-by-object method was adopted to prevent the print head from colliding with parts and detaching them from the build plate. This method has been verified multiple times and is very reliable and easy to print.

Size Introduction:

There are 5 sizes in total, with 3 sizes having versions with a keychain hole.

1. Diameter 12mm, Height 30mm

2. Diameter 20mm, Height 50mm  (with keychain hole version)

3. Diameter 28mm, Height 70mm  (with keychain hole version)

4. Diameter 36mm, Height 90mm  (with keychain hole version)

5. Diameter 44mm, Height 110mm

Key Features:

Material: PLA

no supports

No other parts or materials required besides 3D filament

Easy to print, many have been printed without failure

Notes:

1. Use print-by-object rather than print-by-layer. This is because the first layer only has two perimeters of material, resulting in limited adhesion. This method prevents the impact of the print head transitioning between different parts from detaching parts from the build plate. Additionally, print-by-object often yields slightly higher quality.

2. Set the first layer speed to 20 to improve first layer adhesion and prevent the material from detaching from the build plate when the print head draws small circles.

3. The wall generator uses Arachne because the wall thickness changes are complex at the threads, and Arachne can provide better infill.

4. An automatic brim is set, and the smallest capsule models will have a brim. Please be sure to clean the brim thoroughly, otherwise it will affect the thread engagement, making it very tight and difficult to screw in.

5. All capsules were printed with Bambu Lab PLA, using a flow rate of 1.0. For different printers and materials, the flow rate will affect the tightness of the thread fit, which cannot be universally optimized for all machines. If the threads are too loose or too tight to screw in, you can adjust them appropriately using contour size compensation (position shown in the image below).