Print-in-place and articulated models: what they are and how to print them
Some of the most popular 3D prints need no glue, no screws and no assembly: they come off the printer already moving. Articulated dragons that wiggle, flexi animals, boxes with working hinges. Here’s how they work, where to find them, and how to get them to move freely.
How they work
A print-in-place model is designed with its moving parts printed together, with tiny gaps between them. The printer builds each joint layer by layer, the gap keeps the parts from touching, and once the print is done the parts move against each other. “Articulated” just means the model has joints: a tail made of many linked pieces, or legs that bend.
The gaps are small, usually a few tenths of a millimetre, so these models are a good test of how well your printer is tuned. When the gaps are too small for your printer, the parts fuse and the model won’t move.
Where to find good ones
- Articulated dragons, the classic, in every size and style.
- Flexi animals: cats, sharks, frogs, lizards and more.
- Boxes with hinges and other print-in-place models.
- Fidget toys: spinners, sliders and clickers.
On Yigo’s home page, the Toys & games tab collects articulated and flexi models too. Sort by Popular to see the designs that lots of people have printed successfully.
Tips so the joints move
- Get the first layer right. A first layer squashed too flat spreads out (“elephant’s foot”) and glues the bottom of the joints together. Level the bed and print the first layer at the height your slicer suggests.
- Don’t add supports unless the designer says to. Print-in-place models are designed to print without them, and supports inside a joint are nearly impossible to remove.
- Print a little slower for your first try, especially with a new printer or a new filament.
- Read the model’s notes. Designers often say which layer height or scale they tested. Printing much smaller than intended shrinks the gaps too, and they may fuse.
- Break it in gently. Joints can be a bit stiff straight off the bed. Flex each one slowly, a little further each time, rather than forcing it.
If a joint fused
Try gently twisting the joint back and forth. If it still won’t move, check the first layer and your printer’s calibration, then print a small test first: many designers share a single joint or hinge for exactly this. Our guide to first prints has a few calibration models worth printing.