CatPin Cuts Models for a Better Fit

For those who don’t know the tool: CatPin is Alex Sokol’s Blender add-on for dividing sculpts into printable parts and generating matching pins and sockets for resin and FDM assembly.

We love cats. Our cat does not love our 3D printer. Apparently, a box that makes noises for six to sixteen hours and produces something you are not allowed to knock off a shelf is a deeply flawed product. CatPin offers a more constructive approach to disassembly: plan where a model separates, then give its pieces a way to fit together.

Choose your incision

The toolset includes Straight Cut with a movable, rotatable plane; Curved Cut with editable control points; and Manual Cut for freehand contours or point placement. Polygonal Cut provides Line and Cylinder modes for extracting smaller regions, including vehicle windows and character features. Eyes, mouths and ears can become separate pieces without making the entire head somebody else’s problem. So, this means that you can print different colours and don’t have any waste in materials.

The developer’s feature overview confirms that cuts can be made with or without connectors (Glue is still our favourite connector), and that cutting surfaces and connector placement remain adjustable before finalisation. For a plain division, leave the pin out. Every seam does not need to audition for a furniture catalogue.

Draft first, regrets later

The FAQ positions Easy Mode for straightforward, light-to-medium models: it creates the cut, pin and socket directly. Draft Mode keeps a cutting plan editable, with individual cuts that can be changed, disabled or removed. It suits the more familiar production condition in which someone will have an excellent new idea immediately after you finish.

In the full tutorial, Build Draft previews the resulting parts; Return to Draft restores editing. Approve removes cut history. Keep Original controls backups, while Skip Problem Cuts omits failing cuts from a build. Explode and Collapse separate and reunite parts for inspection. They are viewport operations, thankfully.

A tolerance for everything except the printer

CatPin offers cylindrical, trapezoidal and custom rigid connectors, with position, rotation, scale, width, height and pin-side controls. The documentation excludes articulated, rotating and movable joints. A keyed assembly and an action figure’s elbow are different engineering conversations.

Connector Clearance adjusts the space around the pin; Cut Gap controls separation between cut faces. The tutorial’s asymmetrical-offset option varies lateral and lengthwise spacing. Its 0.3 mm clearance and exaggerated 3 mm gap are demonstration values, not universal settings. Your resin has not signed that agreement.

The FAQ’s fit guidance ties clearance to printer, material and print settings. Treat tolerance as a physical parameter, not a cosmetic preference: a beautiful socket that refuses its pin is still a very small, very expensive disagreement. So, you will be yelling at your printer even more.

Give the Boolean something civilised

The setup instructions use a ZIP installed through Preferences → Add-ons → Install from Disk, followed by enabling CatPin in the 3D Viewport sidebar. Apply object scale and rotation, work at the intended physical dimensions, and use millimetres. The English interface’s dimensional controls expect attention to actual size. A metre-tall desk ornament is a procurement decision.

The geometry requirements call for closed, manifold meshes. Open surfaces, internal faces, self-intersections, overlapping geometry and very thin regions can produce unreliable Boolean or Remesh results. CatPin helps prepare a sculpt for fabrication; it does not repeal topology.

Label the limbs

Export selected parts together as STL, OBJ or FBX; the tutorial uses their object names for the files. Name them before export. Left_Arm is a more useful assembly instruction than Cube.047, however attached you have become to the latter.

Wall thickness, strength, orientation, supports, build volume and final placement remain your responsibility. The cat may provide unsolicited quality assurance, but has yet to produce an acceptable inspection report.

https://superhivemarket.com/products/catpin/

Availability

The current Superhive listing shows Basic at US$24, reduced from US$30; Supporter at US$36, from US$45; and Business/Studio at US$80, from US$100, for up to five team members. Basic and Supporter are one-person tiers. Twelve months of support and updates are included; another twelve months is listed at 25% of the product price. Prices checked on 7 October 2026.