. Wall Loops & Perimeters
For pressure vessels, the walls are your primary defense.
- Recommendation: 6–8 Wall Loops (or enough to make the wall 100% solid).
- The Logic: You want the entire thickness of the manifold wall to be made of continuous, concentric lines rather than a wall-infill-wall sandwich. This forces the fluid to travel through the “grain” of the plastic rather than finding a shortcut through sparse infill.
2. Infill Settings
https://videos.stratasys.com/watch/BKLN6LnxiAakuThq7Hi2Np?
Standard grid or lightning infill will fail under pressure because the air gaps between the lines allow the manifold to compress or “weep” fluid.
- Infill Density: 100%.
- Infill Pattern: Rectilinear or Aligned Rectilinear.
- The Logic: Set your top/bottom layers to a very high number (e.g., 999) to force the slicer to treat the entire part as a solid block.
https://videos.stratasys.com/watch/BKLN6LnxiAakuThq7Hi2Np?autoplay=2&second=105.35
3. Print Orientation
This is the most critical safety decision. 3D prints are anisotropic — they are roughly 30-40% weaker when pulled apart between layers (Z-axis).
- Orientation Strategy: Position the manifold so the Hoop Stress (the pressure pushing outward on the cylinder walls) acts along the continuous XY lines of the print, not across the Z-layers.
- The Logic: Think of the part like a stack of Pringles. If you apply pressure from the inside, it’s much easier to split the stack (Z-axis) than it is to tear an individual chip (XY-axis).
Technical Slicer Checklist
| Feature | Recommended Setting | Purpose |
| Layer Height | 0.15mm – 0.20mm | Thinner layers increase surface area for bonding. |
| Nozzle Temp | Upper end of range (e.g., 280°C+) | Maximizes “inter-layer diffusion” (welding the layers). |
| Flow Rate/Extrusion Multiplier | 1.02 – 1.05 (102-105%) | Slight over-extrusion fills tiny microscopic gaps between lines. |
| Cooling Fan | 0% – 10% | Slow cooling prevents warping and improves layer adhesion. |
| Brim/Raft | Large Brim (10mm+) | PA12-CF is prone to warping; a large brim keeps the base flat. |
Pro Tip: If the manifold must be completely gas-tight or leak-proof at high PSI, consider a post-print annealing cycle or an internal coating. PA12-CF is naturally somewhat porous at the microscopic level; a thin coat of fuel-resistant epoxy on the internal bore can act as a “bladder” while the CF-Nylon provides the structural strength.