Gyroid Squish Ball - one endless wall, two mazes that never meet

Every hole you see belongs to one of two separate mazes. The gyroid is one continuous curved wall that winds through the whole ball and divides it into two channel systems that interlock everywhere but never meet. It contains no straight lines, and it repeats in all three directions.

Maths fact: the gyroid was found by NASA scientist Alan Schoen in 1970. It is a minimal surface: like a soap film, it bends equally in opposite directions at every point. This model uses the standard formula for it, sin x cos y + sin y cos z + sin z cos x = 0, the close approximation that gyroid lattices are built from.

This ball is 60 mm across with 20 mm cells (three across the ball). The wall is a constant 2 mm thick, measured around the surface, not just squeezed from the formula, so the ball has no thin spots to tear. A 1.5 mm flat on the bottom gives it a footprint on the bed.

Print it in TPU for a squish ball. In PLA or PETG it prints as a rigid desk ornament, which does not squish.

Made with Curiosa Tools - curiosa.tools

Schwarz P Version : 

**Print settings (TPU):**
- **Filament:** TPU 95A is the safe default. It is the firmest of the common flexible grades: it gives under a squeeze and springs back. Softer grades (90A, 85A; a lower number is softer) squish more, but they print slower and string more. Try them only once 95A prints cleanly. TPU 85A needs a 0.6 or 0.8 mm nozzle; Bambu's wiki says the 0.4 mm nozzle is not supported for it.
- **Bambu Lab printers:** do not load standard TPU in an AMS, AMS lite or AMS 2 Pro. Bambu's wiki says every TPU except "TPU for AMS" must be fed by hand, and its TPU 95A HF store page says "All AMS Series NOT Compatible". Feed it from the external spool holder. Bambu's "TPU for AMS" does work in the AMS, but it is Shore 68D (Bambu store), much harder than 95A, so it will hardly squish. Bambu lists TPU 85A as incompatible with the A1 series.
- **Speed:** keep the volumetric speed low. Bambu lists 3.6 mm³/s for regular TPU 95A and 12 mm³/s for TPU 95A HF. Use the slicer's TPU profile and do not speed it up. Dry the filament first (TPU takes up water and then strings).
- **Layers and walls:** 0.2 mm layers. The 2 mm wall prints as perimeters; 3 walls and 15 % infill are enough.
- **Bed and supports:** print as the file is oriented, flat spot down. Use no supports: TPU supports are hard to remove, and the ball's lowest few millimetres, where the sphere curves under, simply come out a little rougher. Add a 5 mm brim, because the footprint is small (about 85 mm²). Bambu's wiki lists Smooth or Textured PEI plates with glue (liquid glue or glue stick) for TPU 95A HF.
- **Two-tone version (optional; not test-printed):** the two-colour picture changes colour at 29.2 mm. This is how to get it:
1. Slice with 0.2 mm layers (first layer 0.2 mm).
2. In Bambu Studio's preview, move the layer slider to **layer 147 (29.40 mm)**, right-click the "+" and choose **Add Pause**. OrcaSlicer has the same **Add Pause** command on its layer slider ("Insert a pause command at the beginning of this layer").
3. The printer stops before printing that layer, after 146 layers (29.2 mm), and waits for you to resume (Bambu Lab wiki, "View slicing information"). Swap to the second TPU by hand while it waits, then resume.
4. Use the pause, not "Change Filament": Bambu's wiki says Change Filament works only with an AMS, and standard TPU must not go through one.
- **Weight and time:** about 39.6 g and 2 h 10 min (OrcaSlicer 2.4.2 estimate for a Bambu Lab P1S with Bambu's TPU 95A HF profile, 0.2 mm, 2 walls, 15 % infill, no supports; not a measured print).
- **Slicer warning to expect:** the slicer says the ball "has floating regions" (seen in OrcaSlicer 2.4.2). These are 7 pinhead spots (the largest 0.85 mm²), where a wall begins in mid-air just inside the sphere's skin. They are part of cutting a lattice to a sphere. Printing without supports is still the recommendation: the first layers at those spots may droop or string a little. Supports would cost much more: tree supports add about 17 g and 1.5 h and grow through the inside of the lattice, where TPU supports are very hard to remove. Not test-printed, so this is the slicer's view, not a tested result.
- **Closed printers (P1S, X1C):** the slicer flags the bed as too warm for this TPU (OrcaSlicer code 1000C001, probably the app message "open the front door and/or remove the upper glass"). Do that while printing TPU.