Ever design an action figure and realize the arms flop around like wet noodles—or worse, snap off and send you straight into a rage-quit spiral? Yeah, we’ve all been there. Today, we’re fixing that with hinge joints.
Why Pop-In Hinges?
Pop-in hinge joints are the kind that click together with a satisfying thunk—the sound that makes you feel like a professional toy engineer (or at least like you know what you’re doing). They’re simple, effective, and make your articulated figures feel more like finished products than prototypes.
In this tutorial, I’ll walk you through how to sculpt both halves of a hinge joint in Nomad Sculpt, set up your clearances, and prep it all for 3D printing. It’s part art, part geometry, and about 10% wizardry. So grab your stylus, open Nomad Sculpt, and let’s make a joint that pops.
Step 1: Sculpt the Leg
We’re starting with a basic knee or elbow joint. First, delete your default sphere and add a cylinder—this will be your thigh. Shape it roughly like a leg, then validate it once you’re happy with the proportions.
Next, add some clay and sculpt in the muscle details. Make it a bit heroic—most action figures have that “hero” vibe anyway. Once that’s done, it’s time to make the shin.
Add another cylinder for the shin, narrow it down, and position it so it aligns with the thigh. For the calf muscle, add a sphere, shrink it to fit, and blend it into place. Voxel remesh the parts together and smooth the surface to create one cohesive lower leg.
Step 2: Building the Hinge
Now that we’ve got our leg, it’s time to build the hinge joint.
Start by adding another cylinder to the top of the calf—this will serve as the hinge mount. Center it properly and add a sphere to one side. Clone that sphere and move it to the opposite side so you’ve got two even pegs sticking out. Those pegs are the core of your hinge mechanism.
For the upper thigh, there are two main approaches you can take:
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The Cutaway Method – Use the trim tool to carve out space for the hinge.
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The Sidewall Method – Build two side flanges that hold the hinge in place.
Let’s go through both.
Step 3: The Cutaway Method
For the first approach, select the thigh, and use the trim tool to carve out a square-shaped cavity where your hinge will snap in. Make sure to leave some clearance so it can rotate freely.
This version gives a clean look and decent flexibility, though it can be a bit stiffer depending on print tolerances.
Step 4: The Sidewall Method
For the second approach, add two boxes to the sides of your hinge area and position them so they leave just enough tolerance for movement. Clone one for each side and voxel remesh everything together.
Then, sculpt the area to make it look smooth and natural. This design is slightly bulkier, but it tends to move more smoothly and has better friction control.
Step 5: Print and Test
Export both versions and send them to your 3D printer. Once printed, it’s time for the best part—snapping them together.
You’ll hear that click when the hinge slides into place. That’s not just plastic—it’s victory.
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The cutaway joint gives tighter movement—great for stable poses.
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The sidewall joint moves a bit smoother and feels more natural.
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And if you’re feeling bold, you can even print the entire hinge in place for a seamless, no-assembly joint.
Applications
These pop-in hinges work great for knees, elbows, fingers, and even shoulders if you leave enough rotation space. Once you master this process, you can apply it to nearly any articulated design.
And that’s it—your brand-new pop-in hinge joint straight from Nomad Sculpt and ready for posing.
Oh, and remember—when you hear that perfect click of a joint going in, that’s not just plastic. That’s victory.