Whether you’re printing a small drone frame, a custom phone case, or a large architectural model, getting the size of your 3D print right is critical to success. Print too big, and your model won’t fit in the printer. Print too small, and you might lose important details or compromise strength. But determining the right size isn’t just about measuring—you need to consider printer limits, model design, 材料, もっと. This guide breaks down every factor you need to check, with real-world examples and easy-to-use tables, so you can avoid common size-related mistakes and get perfect prints every time.
1. Start with Printer Specifications: Know Your Printer’s Limits
The first and most important step in determining 3D print size is understanding your 3D printer’s capabilities. Every printer has a maximum 印刷ボリューム (the largest space it can print in), measured in length × width × height. If your model exceeds this volume, it won’t fit—simple as that.
Common 3D Printer Types and Their Print Volumes
Different printer technologies (like FDM and SLA) have different typical print volumes. Below is a breakdown to help you gauge what’s possible with your printer:
| Printer Type | Typical Print Volume (L×W×H) | Example Model | Best For Small/Big Prints? |
| FDM (融合モデリング) | 200×200×200mm to 400×400×400mm | クリーリティエンダー 3 (220×220×250mm) | Versatile—good for small to medium parts (例えば。, ドローンフレーム, おもちゃ) |
| SLA (ステレオリスム造影) | 150×150×200mm to 600×600×400mm | フォームラブフォーム 3+ (145×145×185mm) | Better for small, 詳細な部品 (例えば。, ジュエリー, 歯科モデル); larger SLA printers handle medium parts |
| SLS (選択的レーザー焼結) | 200×200×200mm to 500×500×500mm | EOS P 396 (340×340×600mm) | Ideal for medium to large industrial parts (例えば。, エンジンコンポーネント) |
実世界の例: Fitting a Drone Frame in an FDM Printer
A DIY enthusiast wanted to 3D print a drone frame that was 300mm long, 250幅mm, and 80mm tall. They owned a Creality Ender 3 with a print volume of 220×220×250mm. At first, they tried to print the frame as one piece—but it was too long and wide for the printer. Instead of buying a new printer, they split the frame into two smaller parts (each 150×220×80mm) using CAD software. They printed the two parts separately, then glued them together. The final frame fit perfectly, and the split didn’t affect its strength.
2. Optimize Your 3D Model: Adjust Thickness, Tolerance, and Details
Once you know your printer’s limits, the next step is optimizing your 3Dモデル to ensure it prints correctly at your desired size. Three key factors here are wall thickness, line width, そして 許容範囲—ignore these, and your print might break, have gaps, or fail entirely.
a. 壁の厚さ: Don’t Print Too Thin (or Too Thick)
壁の厚さ is the minimum thickness of your model’s outer layers. If it’s too thin, the print will be weak and might collapse during printing. If it’s too thick, you’ll waste material and time. The right thickness depends on your printer type:
| Printer Type | Minimum Recommended Wall Thickness | ユースケースの例 | What Happens If Too Thin? |
| FDM | 0.8mm | Drone frame, phone case | Walls crack easily; print may warp |
| SLA | 1.5mm | ジュエリー, small figurines | Parts break during post-processing |
| SLS | 1.0mm | Industrial brackets, ギア | Reduced strength; parts may deform |
例: Fixing a Weak Phone Case
A designer tried to print a phone case with 0.5mm walls using an FDM printer (below the 0.8mm minimum). The case looked good at first, but when they put their phone in it, the sides cracked. They redesigned the case with 1.0mm walls (slightly above the minimum for extra strength) and reprinted it. The new case was strong enough to protect the phone and only used 10% more material than the thin version.
b. Line Width: Match It to Your Printer’s Nozzle
Line width is the width of the plastic (or resin) the printer extrudes, determined by the printer’s nozzle diameter (FDM用) or laser spot size (SLAの場合). It affects the smallest details your printer can handle—if your model has details smaller than the line width, they won’t show up.
For FDM printers, the standard nozzle diameter is 0.4mm, so the line width is usually 0.4–0.6mm. If your model has a tiny detail (like a 0.2mm hole), the printer can’t print it clearly. You’ll need to either:
- Enlarge the detail to at least 0.4mm, または
- Use a smaller nozzle (例えば。, 0.2mm) for finer details (though this will slow down printing).
c. Tolerance: Leave Gaps for Spliced Parts
If your model is too big for the printer and you need to split it into parts (like the drone frame example earlier), you need to add 許容範囲—small gaps between the parts so they fit together easily. The standard tolerance for 3D printed parts is 0.1–0.2mm.
例: Assembling a Split Toy Car
A parent printed a toy car split into a body and four wheels. They forgot to add tolerance, so the wheel holes were exactly the same size as the wheel axles. When they tried to attach the wheels, they were too tight and broke the axles. They adjusted the model to add 0.15mm tolerance (making the wheel holes 0.15mm larger than the axles) and reprinted. The wheels now fit perfectly and spun smoothly.
3. Choose the Right Material: It Affects Size and Strength
Different 3D printing materials shrink or expand slightly during printing, which can change your model’s final size. They also have different strengths, so the material you choose might affect how thick you need to make your model (and thus its overall size).
Material Shrinkage and Strength Comparison
| 材料 | Typical Shrinkage Rate (After Printing) | 強さ (Suitable for Large/Small Parts) | に最適です |
| プラ (ポリラトン酸) | 1–2％ | Medium—good for small to medium parts (例えば。, ドローンフレーム, おもちゃ) | 初心者; parts that don’t need extreme strength |
| 腹筋 (アクリロニトリルブタジエンスチレン) | 4–5% | High—good for medium parts (例えば。, ツールハンドル) | 工業部品; parts that need durability |
| PETG (ポリエチレンテレフタレートグリコール) | 2–3％ | High—excellent for medium to large parts (例えば。, storage boxes) | 屋外部品; parts that need flexibility |
例: Compensating for ABS Shrinkage
A manufacturer wanted to print an ABS bracket that needed to be exactly 100mm long to fit a machine. They knew ABS shrinks 4–5%, so they designed the model to be 104mm long (adding 4mm to compensate for shrinkage). 印刷後, the bracket measured 100.2mm—close enough to fit perfectly. If they hadn’t compensated, the bracket would have been 95–96mm long and too small.
4. Adjust Temperature and Layer Thickness: Fine-Tune for Accuracy
Two more factors that affect 3D print size are nozzle temperature (FDM用) そして 層の厚さ. These don’t change the model’s design size, but they can affect how well the printer executes that size—leading to dimensional errors if set wrong.
a. Nozzle Temperature: Get It Right for Flow
For FDM printers, nozzle temperature determines how well the material melts and flows. 低すぎる場合, the material won’t flow smoothly, leading to gaps or undersized parts. 高すぎる場合, the material will ooze, making parts oversized.
| 材料 | Recommended Nozzle Temperature | What Happens If Too Low? | What Happens If Too High? |
| プラ | 190–220°C | Gaps between layers; undersized parts | Oozing; oversized parts; ひも |
| 腹筋 | 230–250°C | Brittle layers; ギャップ | Excessive oozing; 反り |
| PETG | 220–240°C | Poor layer adhesion; undersized parts | Oozing; ひも |
b. Layer Thickness: Balance Speed and Accuracy
層の厚さ is the height of each layer the printer prints. Thicker layers print faster but lead to rougher surfaces and slightly larger dimensional errors. Thinner layers are more accurate but take longer.
ほとんどのプロジェクトで, a layer thickness of 0.2mm works well (balances speed and accuracy). If you need a precise part (例えば。, a gear that needs to fit with another part), use 0.1–0.15mm layers. 大きなために, less detailed parts (例えば。, a storage bin), 0.25–0.3mm layers are fine.
Yigu Technology’s View on Determining 3D Printing Size
Yiguテクノロジーで, 我々は信じている determining 3D printing size is a mix of understanding your tools and optimizing your design—not guesswork. We equip our 3D printers (like the YG-200 FDM model, 250×250×300mm print volume) with clear specification sheets and free slicing software presets that adjust wall thickness and temperature for common materials. For clients, we also offer design checks: if a model is too big for their printer, we help split it or adjust details. Getting size right saves time, 材料, and frustration—so we always advise starting small, testing with a prototype, and tweaking before full-scale prints.
よくある質問:
Q1: My model is slightly smaller than I designed—why?
This is usually due to material shrinkage (ABSに共通) または low nozzle temperature (material doesn’t flow enough). Try increasing the model size by 1–5% (材料に応じて) in your CAD software, or raising the nozzle temperature by 5–10°C. Test with a small prototype first to find the right adjustment.
Q2: Can I print a part larger than my printer’s volume?
Yes—by splitting the model into smaller parts using CAD software (like Fusion 360 or Tinkercad). Make sure to add 0.1–0.2mm tolerance between parts so they fit together. 印刷後, you can glue, screw, or snap the parts together. Just avoid splitting critical structural areas (例えば。, a drone frame’s main support) unless you reinforce the joint.
Q3: What’s the minimum size I can 3D print?
It depends on your printer’s line width (FDM) または laser spot size (SLA). For a standard FDM printer (0.4mm nozzle), the smallest detail you can print clearly is about 0.4mm. For an SLA printer (0.05mm laser spot), you can print details as small as 0.1mm. Anything smaller will be blurry or missing. 例えば, a 0.2mm hole won’t print well on an FDM printer—but it will on an SLA printer.
