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Model a desk robot arm: the wrist

The wrist is small and quick: an extruded knuckle, a flange raised on one of its faces, and the pin it turns on.

Each step shows the Designer as you make it: a feature's dialog filled in with the step's values, with the tutorial card ringing OK, or what the step made. The first time a command appears, a picture shows where it is. The step numbers match the card's in Help > Tutorials.

  1. New part, from File > New part: name Wrist.

    The wrist is a knuckle with a flange: extrude its outline, add a round boss on its face, round the rims and drill the pin hole.

    Model a desk robot arm, step 58: New part made, and what it made selected in the panels

  2. Sketch, from Insert > Sketch: id knuckle, on the XY plane, start 0, -11.

    Sketch the knuckle on a plane 5 mm in front of the centre: a round heel around the pin, tapering to a flat face for the flange.

    Model a desk robot arm, step 59: the Sketch dialog filled in with the step's values, the tutorial card beside it ringing OK

  3. Extrude, from Insert > Extrude: id wrist, profile knuckle, distance 10.

    Extrude the knuckle 10 mm, the width of the forearm's fork.

    Model a desk robot arm, step 60: the Extrude dialog filled in with the step's values, the tutorial card beside it ringing OK

  4. Sketch, from Insert > Sketch: id plate, on the side face of wrist.

    On the flat face, sketch a circle: the tool flange.

    Model a desk robot arm, step 61: the Sketch dialog filled in with the step's values, the tutorial card beside it ringing OK

  5. Boss, from Insert > Boss: id flange, profile plate, body wrist, distance 6.

    Raise it 6 mm as a boss.

    Model a desk robot arm, step 62: the Boss dialog filled in with the step's values, the tutorial card beside it ringing OK

  6. Fillet, from Insert > Fillet: id frontRim, body wrist, radius 1.5.

    Round the front face's rim.

    Model a desk robot arm, step 63: the Fillet dialog filled in with the step's values, the tutorial card beside it ringing OK

  7. Fillet, from Insert > Fillet: id backRim, body wrist, radius 1.5.

    Round the back face's rim.

    Model a desk robot arm, step 64: the Fillet dialog filled in with the step's values, the tutorial card beside it ringing OK

  8. Fillet, from Insert > Fillet: id flangeRim, body wrist, radius 1.5.

    Round the flange's rim.

    Model a desk robot arm, step 65: the Fillet dialog filled in with the step's values, the tutorial card beside it ringing OK

  9. Hole, from Insert > Hole: id pin, body wrist, on the end face of wrist, diameter 8.

    Drill the 8 mm pin hole through the heel.

    Model a desk robot arm, step 66: the Hole dialog filled in with the step's values, the tutorial card beside it ringing OK

  10. Part properties, from the Properties panel: id wrist, name Wrist, material aluminium-6061, color #2a2d31, metallic 0.6, roughness 0.3.

    Name the part Wrist: dark anodised aluminium, like the base.

    Model a desk robot arm, step 67: Part properties made, and what it made selected in the panels

  11. Add connector, from Insert > Add connector: part wrist, id pin, on the start face of wrist, axis the wall face of pin.

    Add a connector on the back face, its axis through the pin hole. The wrist turns about it in the forearm's fork.

    Model a desk robot arm, step 68: Add connector made, and what it made selected in the panels

  12. Add connector, from Insert > Add connector: part wrist, id tool, on the end face of flange.

    Add a connector on the flange's face. Whatever the arm carries is fastened there.

    Model a desk robot arm, step 69: Add connector made, and what it made selected in the panels
Model a desk robot arm, after step 69

Verified against the product in October 2026