If you’re designing parts forLaser Sintering Molding (SLS)—a top-tier powder bed fusion 3D printing tech—great design isn’t just “nice to have.” It’s the difference between a part that cracks mid-use and one that’s strong, 正確な, そして費用対効果. This guide breaks down every critical design rule for SLS, 実世界の例があります, データ, and tips to fix common headaches like warping or stuck powder.
1. Why SLS Design Rules Matter
SLS uses lasers to fuse thermoplastic powders (のようにPA 12 or carbon-filled polyamide) into parts. FDMとは異なります, it doesn’t need support structures—but its powder-based process creates unique design challenges:
- Thin walls can collapse under laser heat.
- Small holes trap unsintered powder (ruining functionality).
- Large flat surfaces warp as the part cools.
これらのルールに従ってください, and you’ll cut reprints, save material, and get parts that work right the first time.
2. Critical SLS Design Guidelines (データ付き & 例)
We’ve organized the most important rules by feature—from wall thickness to text. Each section includes easy-to-use tables and real cases to guide you.
2.1 壁の厚さ: Avoid Collapse & Cracking
Wall thickness is make-or-break for SLS parts. 薄すぎる, and the part will collapse during printing; 厚すぎる, and you waste material (そしてお金).
Key Recommendations by Material
| 材料タイプ | Minimum Wall Thickness (With Support) | Minimum Wall Thickness (No Support) | Preferred Thickness (For Consistency) | Maximum Recommended Thickness |
|---|---|---|---|---|
| PA 12 (ナイロン) | 0.6 mm | 0.7 mm | 1.3 mm | 4 mm |
| Carbon-Filled Polyamide | 1.0 mm | 2.0 mm | 1.3–1.5 mm | 4 mm |
本当の例:
A manufacturer designed a PA 12 bracket with 0.5 mm壁 (too thin!). The laser’s heat melted the thin sections, 原因 80% of the parts to collapse. When they adjusted to 1.3 mm壁, the success rate jumped to 99%—and they still saved 30% material vs. a 4 mm wall design.
ヒントの場合:
Walls thinner than 0.5 mm willoverthicken from the laser’s heat. Stick to the minimums above to avoid distorted parts.
2.2 Hole Sizes: Prevent Trapped Powder
SLS prints holes directly—no need for post-drilling. But small holes trap unsintered powder, which can block fluid flow (バルブ用) or break the part when you try to remove it.
Must-Follow Hole Rules
- Minimum diameter: 1.5 mm (any smaller traps powder).
- ベストプラクティス: Design holes to match standard drill bit sizes (例えば。, 2 mm, 3 mm). If the hole needs to be precise, you can drill it slightly larger post-print.
本当の例:
A medical device company printed PA 12 filters with 1.0 mm holes. 印刷後, they couldn’t remove the trapped powder—rendering 50% of the filters useless. When they increased holes to 1.5 mm, powder came out easily, and the filters worked perfectly for fluid filtration.
2.3 部品サイズ: Stay Within Printable Limits
SLS printers have maximum and minimum size limits. Going beyond them leads to failed prints or low precision.
SLS Size Guidelines
| メトリック | 仕様 |
|---|---|
| Maximum Printable Size | 340 x 340 x 605 mm |
| Recommended Max Size | 320 x 320 x 580 mm (avoids edge warping) |
| 最小機能サイズ | 0.5 mm (printable, but risky) |
| Recommended Min Size | 0.75 mm (for consistent results) |
ヒントの場合:
If your part is larger than 320 x 320 x 580 mm, split it into smaller interlocking pieces. SLS can print parts that fit together perfectly—saving you from oversized print failures.
2.4 公差: Focus Only on What Matters
Tolerance is how much a part’s size can vary. Too many tight tolerances increase print time and cost; too few ruin mating parts (like a lid that won’t fit a box).
SLS Tolerance Facts
- Maximum accuracy: まで 0.3% of the feature size (または 0.3 mm—whichever is larger). 例えば, a 100 mm part can vary by ±0.3 mm.
- 経験則: Only use tight tolerances for mating surfaces (例えば。, a shaft that fits a bearing). For non-critical areas (例えば。, a part’s outer edge), loosen tolerances to save time.
本当の例:
An automotive supplier added tight tolerances (±0.1 mm) to every part of an SLS bracket—even the non-mating edges. This doubled print time and cost. When they limited tight tolerances to just the mating hole, they cut costs by 40% with no loss in functionality.
2.5 Hollow Parts: Add Escape Holes for Powder
Hollow parts save weight and material—but you needescape holes to remove residual powder from the cavity.
Hollow Part Rules
- Minimum escape hole size: 3.5 mm (smaller holes trap powder; larger holes let media in for interior polishing).
- Where to place holes: Put them in hidden areas (例えば。, the bottom of a hollow cup) so they don’t ruin aesthetics.
本当の例:
A luggage brand printed hollow PA 12 handles with no escape holes. 印刷後, the trapped powder made the handles heavy and brittle. When they added two 3.5 mm holes, powder poured out easily—the handles were 25% lighter and passed drop tests.
2.6 Interlocking Parts: Print Functional Assemblies in One Go
SLS’s superpower? Printing interlocking, 可動部品 (like hinges or gears) in a single build—no assembly needed. But you need enough clearance to remove powder.
Interlocking Part Rule
- Minimum clearance: 0.5 mm between moving parts (例えば。, a gear and its axle). More clearance (0.8–1.0 mm) is better for easy movement.
本当の例:
A toy company printed a SLS gear set with 0.3 mm clearance. Powder got stuck between the gears, making them lock up. When they increased clearance to 0.5 mm, the gears spun smoothly—no assembly required.
2.7 Engravings, Embossings & Text: Keep Them Visible
SLS can print logos, 文章, or details directly on parts—but small details wear off during post-processing (like media tumbling).
Detail Guidelines
| Feature Type | Minimum Size Requirement | プロのヒント |
|---|---|---|
| Engravings/Embossings | 1 mm depth/height | Prevents wear during media tumbling |
| Text | 2 mm height | 使用Sans serif fonts (例えば。, Arial) for readability |
| Fragile Letters (例えば。, “i”) | Add a small draft (5–10°) | Stops them from breaking in post-processing |
本当の例:
A electronics brand printed PA 12 cases with 1.5 mm tall text (小さすぎる!). Media tumbling wore the text down, making it unreadable. When they increased text height to 2 mm and used Arial, the text stayed clear—even after polishing.
2.8 Avoid Warping: Skip Large Flat Surfaces
大きな平らな表面 (例えば。, a 200 mm x 200 MMプレート) warp as SLS parts cool. The powder shrinks unevenly, causing the surface to bow or crack.
それを修正する方法
- ルール 1: Avoid large flat surfaces whenever possible.
- ルール 2: If you need a flat surface, 追加 rib骨 (thin support structures) underneath. Ribs should be 0.8–1.0 mm thick and spaced 10–15 mm apart.
本当の例:
A furniture maker printed large flat SLS PA 12 パネル (300 mm x 200 mm) with no ribs. 70% of the panels warped by 2–3 mm. When they added 1.0 mm ribs spaced 12 mm離れています, warping dropped to less than 0.5 mm—perfect for their furniture designs.
3. Yigu Technology’s Take on SLS Design
Yiguテクノロジーで, we’ve helped hundreds of clients fix SLS design issues. 私たちが見る最大の間違い? Overlooking small details—like 0.3 mm clearance for interlocking parts or 1 mm engravings. 私たちのアドバイス: Prioritizefunction first—match wall thickness, 穴のサイズ, and clearance to how the part will be used. 例えば, a medical part needs tighter tolerances than a decorative one. By aligning design with end-use, you’ll get SLS parts that are strong, 正確な, and cost-efficient—every time.
4. よくある質問: Common SLS Design Questions
Q1: Can I print a wall thinner than 0.7 mm for PA 12 if I use support?
はい, but only down to 0.6 mm—and it’s risky. The laser’s heat can still overthicken or collapse 0.6 mm壁. We recommend sticking to 0.7 mm (no support) for consistent results.
Q2: Why do I need to use Sans serif fonts for SLS text?
Sans serif fonts (no small “tails” on letters) have simpler shapes. This makes them easier for the SLS laser to print clearly, and they’re less likely to break off during post-processing compared to serif fonts (例えば。, Times New Roman).
Q3: If my part is larger than 340 x 340 x 605 mm, can I still print it with SLS?
No—SLS printers can’t go beyond their maximum build size. その代わり, split the part into smaller interlocking pieces (と 0.5 mm+ clearance). SLS prints these pieces perfectly, and you can assemble them post-print for a full-size part.