Brim vs Raft: Adhesion of 3D Printed Bed

Navigating the adhesion of 3D printed beds: When to choose edges with rafts

In any 3D printing, it can be said that making the initial layer perfectly pasted is a moment of telling or breaking. Warped, curled or full detachment can send hours of printing sewers. To solve these problems, Slicer software provides powerful tools such as edge and raft. But understand when and Why Choosing one over the other is crucial for consistent success. exist GreatWe are a leader in professional rapid prototyping, and we use advanced SLM metal 3D printing technology every day and face adhesion challenges. This guide delves into edges and rafts to give you the ability to make informed decisions and demanding professional applications for amateur projects.

Why bed adhesion is not only a problem

Think of the first floor as the foundation of the building. Poor adhesion causes cascade failure:

1. Warp: The material is unevenly cooled and shrinks, pulling the corners/edges upwards. Commonly found in ABS, Nylon and large print materials.
2. Separation: The centers in the entire print are in the process, usually due to insufficient surface area or poor bed space.
3. Elephant’s feet: The first layer over-measured causes the bottom to bulge.
4. Poor dimension accuracy: Lifting the corner distorts the expected geometry.

Heating beds, adhesives (glue sticks, hair spray) and surface treatments, but full of rafts are Slicer generation A structure designed specifically for mechanically mitigating these forces.

Edge: Your first layer of stable shield

• What is: one edge Consisting of flat single layers (sometimes 2-3 layers), usually skirt-like structures that extend horizontally outward Very marginal The basics of your printing objects. It is directly integrated into this basic outline.
  Typical edges surround the base of an object to increase surface contact and resist warping.

• mechanism: By extending the surface area bonded to the build board About The periphery of the object, the edges will significantly increase adhesion. This is like an anchor, offsetting the inward pressure caused by heat shrinkage, as continuous layers are cool. It is crucial that It keeps the bottom surface of the part itself intact.

• When to use edges:

  • Small contact area: Printing with narrow foundations or limited contact points (e.g., small feet, micro-sized towers).
  • Materials of the I Ching: ABS, hips, nylon (PA), polycarbonate (PC), where the differential cooling stress is high.
  • Large flat model: Reduce edge lifts and corner warping with boxes, sheets or large flat bottom parts.
  • Doubtful bed adhesion: When conditions are not perfect (slightly imperfect levels, dust/wearing build surfaces).
  • Save materials/time: When the raft solves the problem unnecessarily.

• advantage:

  • Targeted stability: The peripheral lift force is specifically offset.
  • Minimum material waste: Add extra plastic, reduce costs and print time.
  • Easy to delete: A clean slap is required with minimal post-treatment, usually leaving a smooth (ER) bottom.
  • Keep the bottom details: The parts themselves sit directly on the build board, ensuring maximum dimensional accuracy and finish on the bottom surface.

• shortcoming:

  • Limited fixes: Only helps with edge lifting; if it’s struggle All Basic lift due to severe warping or very poor adhesion over large areas.
  • Remove line: Thin lines can be left on the edge of the interface or require a slight polish/decoration.
  • Not suitable for serious dishes: If the center of the build board is not perfectly horizontal/flat, the edges will not resolve the adhesion problem in part of the middle.

• Best Practices:

  • Adjust width: Increase Brim Width (usually 5-20mm) for larger prints or highly warped materials.
  • Edge separation distance: A slight increase Brim Separation Distance (e.g. 0.1-0.2mm) For ease of removal without damaging the parts. Calibrate carefully!

Raft: Built on foundation

• What is: one raft It’s thick Multi-layer grid (usually 2-5 layers thick) Build directly Below Your entire print. Then print your object top This sacrificial structure is not directly on the build board.
  The raft creates a thick platform under the entire printing bottom.

• mechanism: It creates a completely new, broader and flatter basis specifically targeting adhesion and upgrade compensation:

  1. Adhesion: Larger surface area ensures a strong attachment to the build board, which is much stronger than the edges.
  2. Thermal insulation: Its thickness helps maintain a more stable thermal environment Actual Partially, reduce thermal shock.
  3. Level Compensation: A small amount of inconsistency in the average construction of plate level/planarity of thick raft layers.
  4. buffer: A slight flexibility is provided during cooling to absorb residual stress.

• When to use a raft:

  • Minimal contact area/complex minimum foundation: Contact point or object of complex/unstable base geometry.
  • Extreme twist: When using materials on infamous severe warping (e.g., no fill nylon or ABS without shell).
  • Suspicious construction slabs are flat/flat: Compensate for unbalanced beds or smaller level errors.
  • maximize "stamp": When dealing with exotic materials, the necessary picky or coatings to build the surface.
  • Dissolved Support (FDM): When supported on top of the raft using aqueous solution, it helps to facilitate easier interface separation.
  • Print directly on texture/vertical surface model: Ensure that the fixed contacts are required for parts in this direction.

• advantage:

  • The strongest adhesion: Unrivaled grip when dealing with the most challenging prints.
  • Fields at level: Effectively mitigate minor build board defects.
  • Thermal control: The first layer of the part is better isolated, thereby improving the overall layer bond uniformity.
  • The bottom of the shield complex: Protect complex basic details during initial adhesion.

• shortcoming:

  • Resource-intensive: Use more materials and greatly increase printing time.
  • Complex post-processing: Removing the raft requires effort – prying, cutting or sanding – almost always leaves a rougher finish on the actual bottom surface of the part, requiring additional finishing.
  • Dimensional accuracy impact: RAFT-PRINT interface (Air Gap/Raft Top Spacing) It must be calibrated accurately to avoid poor bonding of elephants.
  • The ideal at the bottom of the aesthetic is: It is crucial to avoid using the bottom surface texture of the part as it will be printed on top of the raft, thus inheriting its texture or requiring intensive sanding/polishing.

• Raft best practices:

  • Tuning air gap: The gap between top Raft layer and The first The first layer of the part (Raft Top Gap/Air Gap) is crucial. Too small = extreme elephant’s feet, too large = weaker risk of bonding and layer separation. Start to be low, and slightly increase if needed.
  • Adjust the raft density: Increase Raft Density Have stronger adhesion, but print time/more material.
  • For real necessity: Given the overhead, rafts are only deployed when bushes or other measures are insufficient.

Bollinger and Raft: The key difference at a glance

feature	edge	raft
structure	Single (or very few) planar layers About base	Multi-layer mesh Below The whole foundation
Contact with part	Fusion to edge The basics of parts	Part printing top Raft
Key Advantages	prevention Edge weightlifting/angle bending	Strong overall adhesion, horizontal board
Material/time waste	Low	High
Easy to remove	Simple (possibly minor edge effects)	Difficult (dirty/rough bottom surface)
Surface quality	Original bottom surface preservation	The bottom surface becomes rough
The accuracy of dimensions	The bottom is great	Slight loss/complexity at the bottom
Best for:	Small function, edge lift, slight warping	Severe warping, tiny contact points, board problems

Which adhesion technique should you use? Practical Decision Making Guide

Don’t blindly default to one or the other. Ask the following questions:

1. Geometric analysis:

   • More than 60% basic coverage and stability? Don’t try it first.
   • Minimum edge contact expected (e.g., slender pillars)? raft Probably the best.
   • Large base with twists? edge It should be enough.
   • Intricate, minimal texture key foundation? Try advanced adhesives & edge Only absolutely essential.

2. Material behavior:

   • PLA, simple material: Usually not, or edge For tricky little parts.
   • ABS, ASA, Nylon, PC: edge Strongly recommended for larger prints; consider raft For large, complex/easy parts.
   • Exotic materials: Study the behavior of specific materials and be conservative. raft It is usually necessary.

3. Perfect build board:

   • Completely level and consistent? Your flexibility (more likely).
   • Slightly shed or textured/sacrificial board? raft Maybe it’s a lifesaver.

4. Post-processing latitude:

   • The bottom surface key? Avoid rafts or budgets for major completions.
   • Part Hide/Function? The rough bottom of the raft is not the main problem.

5. Time and cost sensitivity:

   • Agile prototype? Minimize overhead – Select edge Unless otherwise forced.
   • One-time tasks are crucial? use raft If there is any obvious risk of adhesion.

Conclusion: Master the basics of perfect prints

Choosing between edges and rafts is about understanding the structural pressures, material behaviors, and balance efficiency and reliability of the print. edge Excellent on stable edges of stable edges, thus maintaining the dimensional accuracy below. raftalthough resource-rich, offers the greatest adhesion insurance, upgrade benefits, and is essential for extreme challenges.

exist Greatwe bring this nuanced understanding to each project. As Prime Minister Rapid Prototyping Company Utilize the cutting-edge SLM 3D Printerwe constantly navigate the complexity of material attachment – ​​from complex metal prototypes using advanced powders to demanding polymer parts. Our in-depth process knowledge ensures advanced success rates. And, our comprehensive Post-processing service Proficient in dismantling and completing challenges, providing preparation for real-world applications. Whether you are facing the continuous warping of the subcontractor or need a consistently accurate functional prototype, Great Combine technology, expertise, and committed to problem solving to bring your vision to life.

Ready to overcome the 3D printing challenge with unparalleled accuracy and reliability? Explore the features of Greatlight and get expert support for your next custom rapid prototyping project!

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FAQ: Answers to the edges, rafts and bed adhesions

1. Q: Can I use edges and rafts together?

   • one: Technically possible on some slicers, but Very rarely necessary or beneficial. The raft solves the adhesion at the base level. Add edges Go to the raft (Since the parts base is now a raft) is usually redundant and waste time/material.

2. Q: After using the raft, my bottom was rough and bumpy. Can this be solved?

   • one: Yes, but it takes effort. This roughness is inherent in how the parts are combined with the raft. Post-processing, such as grinding, filing or processing (milding, CNC) is required to achieve a smooth effect. Consider measurement "Air gap" And increase it slightly (usually in 0.1mm increments) to balance the adhesion and easier removal/finement effects.

3. Q: Edge or raft is better suited to prevent spaghetti failure (printing loose in the air)?

   • one: raft Provides the strongest overall adhesion and is much better at preventing catastrophic mid-print disengagement due to adhesion losses On the entire base. The main goal of the edge is the edge lift, but the entire base popped up under active force provides less safety.

4. Q: How "skirt" Is it different from the edge or raft?

   • one: one skirt Pure diagnosis/preparation. It draws one or more loops About (but not touch) the print area. It helps to enable the nozzle and check the leveling/flow. It provides No obvious adhesion benefit.

5. Q: Why does my edge still cause warping?

   • one: Several possibilities:

     • Too small in width: Not enough stability.
     • Bed/adhesive: Poor beds or insufficient surface adhesion can damage the edges.
     • Materials/Drafts: Extreme warping materials require wider edges or rafts. Environmental drafts are killers.
     • calibration: Excessive repulsion/nozzle height can lead to a poor layer of bonding Within The edge itself.

6. Q: Will bed adhesion technology affect the surface quality of the bottom?

   • one: indirect, Yes. Severe warping caused by poor adhesion can propagate the pressure upwards, resulting in changes in the layer, poor bonding of the layer on the layer, or visible deformation of the entire print. Good adhesion promotes the accuracy of the overall dimension.

7. Q: Are these technologies related to resin (SLA/DLP) printing?

   • one: Core concepts exist, but implemented in different ways:

     • "edge": More common and implemented to increase cross-sectional area and peel force for flat “raftless” prints.
     • "raft": Very common. Resin printers almost always produce highly customizable “raft” or base structures at support/contact points. This is the key platform adhesion and model orientation.

Mastering the edges and rafts gives you powerful and confident printing large, small, simple and complex models. By strategically applying these tools, you can maximize adhesion success and minimize frustrating failures.