Slide 003: Support Structures, Adhesion, and Pre-Print Checklist

Slide Visual

Slide Overview

This slide covers support structure generation, bed adhesion strategies, and the final pre-print verification checklist. These are the last critical steps before sending a job to the printer, and errors here are the most common cause of print failures in educational environments.

Instruction Notes

Support Structures

Supports are temporary structures printed beneath overhangs and bridges to prevent sagging and collapse. Key concepts:

• Overhang threshold: Most slicers default to generating supports for angles greater than 45° from vertical. Some materials (PLA) can handle up to 55-60° without supports.
• Support types:
• Linear/Grid supports: Traditional columnar structures. Easy to predict but leave more surface marks. Z-distance typically 0.2mm (1 layer gap).
• Tree supports: Branch-like structures that reach around the model. Use less material, leave fewer marks on surfaces, but take longer to compute in the slicer.
• Organic supports: PrusaSlicer/OrcaSlicer variant of tree supports with smoother, more natural branching paths.
• Support interface layers: 2-4 dense layers at the top of supports where they contact the model. Usually printed at 75-90% density for a smooth contact surface that still separates cleanly.
• Soluble supports: PVA (water-soluble) or HIPS (limonene-soluble) used on dual-extruder printers for complex geometries requiring clean support removal.

Bed Adhesion Types

Type	Description	When to Use
Skirt	Outline around part (no contact)	Default — primes nozzle, verifies leveling
Brim	Flat border attached to part base	Small footprint parts, warping-prone materials
Raft	Full platform under the part	Uneven beds, ABS, very small contact areas

Brim width: typically 3-8mm. Raft adds 0.3-0.5mm Z-offset and 2-4 extra layers beneath the part.

Pre-Print Verification Checklist

Before clicking "Print," students must verify: 1. Model orientation — minimize supports, strongest layer direction aligned with load 2. Layer preview — scrub through every layer in preview mode looking for defects 3. Estimated print time — verify the job fits within available lab time 4. Material estimate — confirm enough filament remains on the spool (weigh spool: empty spool is typically 200-250g) 5. First layer preview — check adhesion footprint is adequate 6. Support placement — verify supports reach all necessary overhangs without excessive material waste 7. Seam position — set Z-seam to "sharpest corner" or "rear" to hide the layer start point

Key Talking Points

1. The 45° rule is a guideline, not a law — material, cooling, and speed all affect overhang capability
2. Brims are your best friend for preventing warping; they add minutes to print time but save hours of failed prints
3. Always scrub through the layer preview before printing — five minutes of preview review prevents five hours of wasted print time

Learning Objectives (Concept Check)

• [ ] Students can determine when supports are needed and select appropriate support type
• [ ] Students can choose the correct bed adhesion method for different scenarios
• [ ] Students can complete a pre-print verification checklist before submitting a job

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Last Updated: 2026-03-19