Attach a generator’s pieces to your parts

Join a hinge leaf to a box, or cut a snap catch into a base, so they print as one part.

A generator that makes several pieces — a hinge’s two leaves and its pin, a snap fit’s arm and catch — normally gives you each one as a separate part. That is often what you want: print the hinge on its own and screw it on. Attach to is for when a piece belongs to something you built, like a hinge leaf that should be part of a box and the other leaf part of its lid.

An attached piece becomes part of its part. It is joined into it in the view, in every export and on the plate, while the generator stays editable: change the hinge’s knuckle count and the leaf in the box changes with it. A piece that cuts — a snap fit’s catch window — is cut out of its part instead. You can attach a piece to one of your parts, or to a piece of another generator, such as an enclosure’s base.

It is optional, piece by piece. Every row starts at *Not attached*, which is the generator exactly as before. Attach one leaf and leave the other loose if that is what the design needs.

Pieces must touch to join. Attaching moves nothing, so place the generator where its pieces meet their parts. If one doesn’t reach, OwlCAD says so everywhere it can: a red dashed line across the gap with its length, a warning on both rows in the scene tree, a line under Attachments in Properties, and a row in Print check. Move it back into contact and the warnings clear.

Where it works. The generator and its parts must sit side by side at the top of the scene, or side by side inside one component. Combining a generator with a box welds the whole generator into one solid, hinge pin and all, so nothing could turn; make a component of them instead.

Copies and Bake. Duplicate a hinge together with its box and the copy attaches to the copied box; copy the hinge alone and it comes loose. Cut and paste is a move, so it stays attached. Bake turns the generator into plain parts and leaves each attached piece joined into its part for good.

1. Select a generator that makes several pieces, such as a Pin hinge or a Snap fit.
2. In the Properties panel, find Attach to. It has one row for each piece the generator makes.
3. Pick a part for a piece — Box for Hinge leaf A, say. Pointing at a row highlights its piece in the view.
4. Move the generator until each attached piece touches its part. Attaching doesn’t move anything.