Tech Tip: 3 Ways to Create Mate Connectors Between Features in Onshape

Mates are the backbone of Onshape’s assembly modeling and simulation. Mates utilize mate connectors, which are “markers” that can be placed either between parts or on parts. Because Onshape uses this approach, designers can start planning the motion between parts much earlier in the design process – fully detailed CAD models are not necessary for motion planning.

At this level of abstraction, designers might find themselves creating mate connectors between entities. Here are three powerful ways to create Mate Connectors between entities.

1. The “Between Entities” Option

The most direct way to find the exact center between two features is to use the built-in Between entities option in the standalone Mate Connector dialog.

How to use it:

1. Click the Mate Connector tool in the Part Studio toolbar.
2. In the dialog box, change the drop-down menu from On entity to Between entities.
3. Select your two target entities; these can be faces, edges, or vertices from different features.
4. Onshape will instantly calculate the exact midpoint or mid-plane between your selections and place the Mate Connector there.

Pro Tip: You can still use the “Realign” and “Move” options within this dialog to fine-tune the orientation after finding the center point.

2. Standalone Mate Connectors with Offsets and Realignments

Sometimes the exact spot you need between two features is not a midpoint. In these cases, you can anchor a Mate Connector to one feature and use exact numerical offsets to position it relative to another.

How to use it:

1. Open the Mate Connector tool and anchor it to a known entity on your first feature.
2. Check the Move box in the dialog.
3. Use the X, Y, and Z offset inputs to drive the Mate Connector exactly where it needs to be. You can even type equations or variables into these boxes to link the offset directly to the dimensions of your second feature.
4. If the axes are facing the wrong way, check the Realign box to point the primary or secondary axis toward an edge or face on the secondary feature.

3. Referencing an Existing Mate Connector

Sometimes, the geometry of one feature doesn’t offer the immediate inference points you need to easily relate it to a second feature. In these situations, the easiest path is to base your new Mate Connector on an existing Mate Connector. Onshape allows you to stack references, making it simple to bridge complex relative placements.

How to use it:

1. Click the Mate Connector tool in the Part Studio toolbar.
2. For your Origin entity, instead of clicking a face or vertex, select a previously created Mate Connector (either in the graphics area or from the Feature List).
3. The new Mate Connector instantly inherits the exact location and orientation of the referenced one.
4. From here, you can check the Move or Realign boxes to translate or rotate the new Mate Connector away from the original, effectively stepping your way to the precise location you need between complex features.

Capturing Design Intent

By mastering these three methods – utilizing the Between entities tool, driving precise offsets and realignments, and referencing existing Mate Connectors – you can capture your exact design intent and make your Part Studios and Assemblies significantly more robust.