How attachments become joints

Select the interface, keep the original part#

Return to our two sleeves at a corner. Each sleeve supplies manufactured geometry, but the region used to create a connector may be smaller than the whole sleeve. A connection port exposes that region and identifies its owning body.

An Attachment Connection records the selected ports and connection mode. It leaves the original instances editable. If a sleeve changes, the connection can regenerate from the changed source geometry.

Hull fills between the selected regions#

Hull computes a convex envelope around the participating port regions. It can bridge a gap between the original bodies, making a filled corner joint. Applicable clearances then preserve required empty space.

The envelope follows the extremes of the selected regions. A port covering an entire sleeve can produce a much bulkier connector than a small, deliberately placed port. Inspect access and material usage rather than treating Hull as a local fillet.

Union coordinates bodies without bridging a gap#

Union contributes the selected port regions without adding a Hull or Strut bridge. It groups the owning bodies and applies the shared clearances.

Use it when the source geometry already overlaps appropriately or when that shared clearance scope is the intended result. If the placed bodies remain separated in space, choosing Union does not create the missing bridge. A grouped export is not proof of one physically connected solid.

Strut adds explicit connecting members#

Strut adds circular connectors between participating port centers. Radius controls their thickness. This can leave a more open structure than a filled Hull.

Check the actual paths and the remaining geometry after clearance subtraction. A valid center-to-center connector can still block a tool, remove useful space, or be inappropriate for the expected load direction.

A connection has a scope#

All participating owning bodies must resolve to the same material. Ports on the same body can connect several relationships into one printable component. Ports on distinct bodies preserve those bodies' independent branches unless another connection explicitly joins them.

This is useful for multi-part attachments: one half of a clamp can join a mounting bracket while the other half remains a separate manufactured part.

Placement and manufacturing are separate decisions#

An assembly mate aligns compatible interfaces and propagates dependent pose. An Attachment Connection determines printed-body grouping and connector geometry. It does not move the attachments into place.

First position the parts so their intended interfaces make sense. Then select ports, choose the connection mode, and inspect the final joint and its shared clearances.

Create one joint deliberately, then repeat#

Start with Add connection on a selected attachment and use Edit participants to choose the other ports. Compare modes through reversible edits. Check source-body ownership, material, passages, and access before repeating the pattern.

For a frame whose joints follow its layout, + Add → Connect adjacent attachments creates eligible default connections in one undoable action. Already-connected sites are left as authored. Use the explicit participant workflow for exceptions.

See Attachment connections for exact eligibility, material propagation, editing, and export behavior.