Tech Tip: How to Use the Pin Slot and Tangent Mate for Complex Sliding Motion

There are many mechanisms that incorporate a sliding motion, sometimes combined with a rotational movement of a pin. Most commonly, just a linear sliding motion can be achieved with Onshape’s Slider Mate or, if a rotating pin is required as well, with the Pin Slot Mate.

If there is a slot that is not parallel to one of the axes, you might simply need to realign your mate connector's secondary axis.

You can achieve the same result using a sketch combined with a tangent mate, which also works on a non-linear slot.

This Tech Tip shows you this workflow as well as a sliding mechanism following a 3D curve.

Using Parts, Sketches, and a Non-Linear Curve for a Sliding Motion

To realize a motion along a non-linear curve, add the Slider Plate, Pin, and their sketches to the Assembly. Group or mate each of the parts to their own sketch, including a Planar Mate to ensure that the Pin remains upright. Then use the Pin’s center point (sketch) as a vertex for a Tangent Mate with the Slot curve.

Using a 3D Curve to Define a Sliding Motion

In the last and most complex example, we are using a Tangent Mate to have a Pin slide along a 3D curve. Here we are using a cylindrical body so we will also have a Cylindrical Mate.

Extra Tip: Use a 3D fit spline to combine multiple segments of curves or sketches into one single 3D curve. To add a spline or curve to an Assembly create a Composite Part using the curve.

Learn more about different Mates in the Onshape Help documentation or from the following resources:

• Learning Center Article: Mating Basics
• Tech Tip: How to Align Slot Mates in Onshape
• Tech Tip: How to Sketch Slots

Watch the video below to see this Tech Tip’s easy-to-follow workflow. Then, look at the setup yourself in the public document Tech Tip: Advanced mating techniques.

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