When working with complex or large 3D prints, like intricate signs, swords, or detailed models, you’ll often find that they’re simply too big to fit on one build plate. This is where key and cut techniques come into play. By breaking a large design into smaller, printable pieces, and then using key and cut connections, you can not only assemble your print with precision but also enjoy several other benefits.
In this article, we’ll explore what key and cut techniques are, why they’re so important in multi-part 3D prints, and how you can create them in Nomad Sculpt. By the end, you’ll have a firm grasp of how to implement this process into your projects for professional-quality results.
What Are Keys and Cuts in 3D Printing?
“Keying” in 3D printing refers to the creation of connection points—commonly known as keys—that help two separate parts align and fit together perfectly. Keys typically consist of two parts:
• The male part: A protrusion that will fit into a corresponding space.
• The female part: A cutout designed to receive the protrusion.
These keys and cuts allow parts to snap together, ensuring a secure connection and accurate alignment.
Why Are Keys So Important in Multi-Part Prints?
There are several reasons why keys and cuts are so widely used in multi-part 3D prints:
• Improved alignment: Keys help parts fit together with precision, reducing the chance of misalignment.
• Enhanced structural integrity: The snug fit of keyed parts helps strengthen the final assembly.
• Easier assembly: By creating natural guide points, keys make the assembly process more intuitive and less error-prone.
• Reduced post-processing: When parts fit together accurately, there’s less need for sanding, trimming, or adjusting.
• Improved glue performance: Keys create better surfaces for glue or adhesive, resulting in stronger bonds.
• Facilitated modular design: Keys allow parts to be easily disassembled and reassembled, perfect for modular systems or projects that require flexibility.
Creating Keys and Cuts in Nomad Sculpt
Now that you understand the importance of keys and cuts, let’s look at how to create them using Nomad Sculpt. We’ll walk through two scenarios:
1. Creating a key cut for joining two parts.
2. Splitting one part and creating a key cut for reassembly.
Scenario 1: Joining Two Separate Parts with a Key Cut
1. Add a Cube: Start by adding a cube to your scene in Nomad Sculpt.
2. Position the Key: Move the cube into position where the key will be. Adjust the size and placement to fit your specific design. For example, you may want to fit a shoulder joint into a robot body.
3. Voxel Remesh: Once you’re satisfied with the key’s position, merge the key and the part it’s attached to using a voxel remesh. This will combine the two into one solid piece.
4. Clone and Cut: Clone the part (such as the arm), hide the original, and perform another voxel remesh. This will create the corresponding cut. When you unhide the original part, you’ll see how the key fits into the cut.
5. Adjust for Fit: It’s important to make the cloned part slightly larger, ensuring the cut is a bit bigger than the key. This gives your parts some clearance and ensures they’ll fit together easily.
Scenario 2: Splitting One Part and Creating a Key
1. Split the Part: If you’re working with a single part that needs to be split, start by selecting the Split tool in Nomad Sculpt. Use the Square Split option and draw a line through the part where you want to divide it.
2. Create the Key: After splitting the part, add another cube to the scene. Size and position this cube to act as your key. Be sure the key is large enough to provide stability but not so large that it risks failure during printing.
3. Voxel Remesh: Merge the cube and one half of the part using voxel remesh. Then, duplicate the part and scale up the cube slightly before cutting it from the other half. This will create the larger cut for the key.
4. Check the Fit: Once both halves have their corresponding key and cut, you can assemble them in the digital environment to check that they fit snugly.
Design Considerations for Keys and Cuts
When designing your key and cut system, there are a few key factors to keep in mind:
• Clearance and Tolerance: 3D prints aren’t perfect, so leave some clearance between the key and cut to account for imperfections. A gap of around 0.1 to 0.2 mm is usually sufficient, but this may vary based on your printer’s accuracy.
• Key Shape: While simple cylindrical or rectangular keys are common, feel free to experiment with different shapes. Square or polygonal keys can help prevent rotation, making them great for parts that need extra stability.
• Key Depth and Size: The larger the part, the deeper your key should be. Just be mindful of not placing it too close to the edges of your printed parts to avoid structural weaknesses.
• Orientation: Be thoughtful about how you orient your parts during printing. Excessive support material could cause keys and cuts to lose their precision, leading to misalignment during assembly.
Transform Your Prints with Keys and Cuts
For multi-part 3D prints, the key and cut technique is an invaluable tool that not only ensures precise alignment but also adds structural integrity and makes the assembly process easier. By designing and implementing a key and cut system, you’ll take your 3D prints to the next level, transforming them from good models into professional builds.