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Model a desk robot arm: the assembly

The assembly puts the eight parts together. Its parameters drive the joints, so posing the arm is changing a number, and the fasteners are replicated onto connectors, so each lands on every hole it belongs in.

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 assembly, from File > New assembly: name Desk arm.

    The assembly brings it together: parameters for each joint, the parts inserted (both links from one document at their own sizes), the joints with their limits, and the screws and nuts replicated onto their holes.

    Model a desk robot arm: where New assembly is, ringed in its menu, the tutorial card ringing it on the toolbar too where it has a button
    Model a desk robot arm, step 122: New assembly made, and what it made selected in the panels

  2. Parameter, from Insert > Parameter: name yaw, value -35, unit deg.

    Add the parameter yaw, -35 degrees: how far the shoulder turns on the base.

    Model a desk robot arm, step 123: Parameter made, and what it made selected in the panels

  3. Change parameter, from the Properties panel: name yaw, min -170, max 170.

    Give yaw its range, -170 to 170 degrees: the values the design is drawn for.

    Model a desk robot arm, step 124: Change parameter made, and what it made selected in the panels

  4. Parameter, from Insert > Parameter: name shoulder, value 60, unit deg.

    Add the parameter shoulder, 60 degrees: the upper link's angle at the shoulder.

    Model a desk robot arm, step 125: Parameter made, and what it made selected in the panels

  5. Change parameter, from the Properties panel: name shoulder, min -10, max 120.

    Give shoulder its range, -10 to 120 degrees: the values the design is drawn for.

    Model a desk robot arm, step 126: Change parameter made, and what it made selected in the panels

  6. Parameter, from Insert > Parameter: name elbow, value -80, unit deg.

    Add the parameter elbow, -80 degrees: the forearm's angle at the elbow.

    Model a desk robot arm, step 127: Parameter made, and what it made selected in the panels

  7. Change parameter, from the Properties panel: name elbow, min -150, max 150.

    Give elbow its range, -150 to 150 degrees: the values the design is drawn for.

    Model a desk robot arm, step 128: Change parameter made, and what it made selected in the panels

  8. Parameter, from Insert > Parameter: name wrist, value -40, unit deg.

    Add the parameter wrist, -40 degrees: the wrist's angle.

    Model a desk robot arm, step 129: Parameter made, and what it made selected in the panels

  9. Change parameter, from the Properties panel: name wrist, min -90, max 90.

    Give wrist its range, -90 to 90 degrees: the values the design is drawn for.

    Model a desk robot arm, step 130: Change parameter made, and what it made selected in the panels

  10. Parameter, from Insert > Parameter: name grip, value 4, unit mm.

    Add the parameter grip, 4 mm: how far each jaw slides open.

    Model a desk robot arm, step 131: Parameter made, and what it made selected in the panels

  11. Change parameter, from the Properties panel: name grip, min 0, max 11.

    Give grip its range, 0 to 11 mm: the values the design is drawn for.

    Model a desk robot arm, step 132: Change parameter made, and what it made selected in the panels

  12. Insert component, from Insert > Insert component: id base, part base.

    Insert the base at the assembly's origin. It is the one component no joint moves.

    Model a desk robot arm: where Insert component is, ringed in its menu, the tutorial card ringing it on the toolbar too where it has a button
    Model a desk robot arm, step 133: Insert component made, and what it made selected in the panels

  13. Insert component, from Insert > Insert component: id turntable, part turntable.

    Insert the shoulder. Where it lands does not matter: the joint in the next step places it.

    Model a desk robot arm, step 134: Insert component made, and what it made selected in the panels

  14. Joint, from Insert > Joint: id yaw, component turntable, connector bottom, angle yaw.

    Put the shoulder on the base with a revolute joint, from its bottom connector to the base's top one. The yaw parameter is its angle, kept between -170 and 170 degrees.

    Model a desk robot arm: where Joint is, ringed in its menu, the tutorial card ringing it on the toolbar too where it has a button
    Model a desk robot arm, step 135: Joint made, and what it made selected in the panels

  15. Insert component, from Insert > Insert component: id upper, part link.

    Insert the link as the upper arm, 160 mm between its pivots.

    Model a desk robot arm, step 136: Insert component made, and what it made selected in the panels

  16. Joint, from Insert > Joint: id shoulder, component upper, connector proximal, angle shoulder.

    Join the upper link's near end to the shoulder's pivot with a revolute joint, turned by shoulder.

    Model a desk robot arm, step 137: Joint made, and what it made selected in the panels

  17. Insert component, from Insert > Insert component: id fore, part link.

    Insert the same link document again as the forearm, slimmer and shorter: length 130, width 14, gap 10, hub 13, tip 11. One document, two parts.

    Model a desk robot arm, step 138: Insert component made, and what it made selected in the panels

  18. Joint, from Insert > Joint: id elbow, component fore, connector proximal, angle elbow.

    Join the forearm's near end to the upper link's far end, turned by elbow.

    Model a desk robot arm, step 139: Joint made, and what it made selected in the panels

  19. Insert component, from Insert > Insert component: id wrist, part wrist.

    Insert the wrist.

    Model a desk robot arm, step 140: Insert component made, and what it made selected in the panels

  20. Joint, from Insert > Joint: id wristJoint, component wrist, connector pin, angle wrist.

    Join the wrist into the forearm's fork, turned by wrist.

    Model a desk robot arm, step 141: Joint made, and what it made selected in the panels

  21. Insert component, from Insert > Insert component: id gripper, part palm.

    Insert the gripper.

    Model a desk robot arm, step 142: Insert component made, and what it made selected in the panels

  22. Joint, from Insert > Joint: id mount, component gripper, connector mount.

    Fasten the gripper to the wrist's flange. A fastened joint holds it still.

    Model a desk robot arm, step 143: Joint made, and what it made selected in the panels

  23. Insert component, from Insert > Insert component: id jawA, part jaw.

    Insert a jaw.

    Model a desk robot arm, step 144: Insert component made, and what it made selected in the panels

  24. Joint, from Insert > Joint: id gripA, component jawA, connector slide, offset grip.

    Put the first jaw in its rail with a slider joint. Its offset is the grip parameter, 0 to 11 mm.

    Model a desk robot arm, step 145: Joint made, and what it made selected in the panels

  25. Insert component, from Insert > Insert component: id jawB, part jaw.

    Insert a second jaw from the same document.

    Model a desk robot arm, step 146: Insert component made, and what it made selected in the panels

  26. Joint, from Insert > Joint: id gripB, component jawB, connector slide, offset grip.

    Put the second jaw in the other rail, driven by the same grip, so both jaws open and close together.

    Model a desk robot arm, step 147: Joint made, and what it made selected in the panels

  27. Insert component, from Insert > Insert component: id shoulderBolt, part screw.

    Insert the screw document as the shoulder bolt, 8 mm across and 55 mm long.

    Model a desk robot arm, step 148: Insert component made, and what it made selected in the panels

  28. Replicate, from Insert > Replicate: id shoulderBolt, connector seat.

    Replicate the bolt onto the shoulder's boltFace connector. It goes through both hubs and the upper link between them.

    Model a desk robot arm: where Replicate is, ringed in its menu, the tutorial card ringing it on the toolbar too where it has a button
    Model a desk robot arm, step 149: Replicate made, and what it made selected in the panels

  29. Insert component, from Insert > Insert component: id shoulderNut, part nut.

    Insert the nut document for the shoulder bolt.

    Model a desk robot arm, step 150: Insert component made, and what it made selected in the panels

  30. Replicate, from Insert > Replicate: id shoulderNut, connector seat.

    Replicate the nut onto the shoulder's nutFace connector, on the other side.

    Model a desk robot arm, step 151: Replicate made, and what it made selected in the panels

  31. Insert component, from Insert > Insert component: id elbowBolt, part screw.

    Insert a screw as the elbow bolt, 8 by 34 mm.

    Model a desk robot arm, step 152: Insert component made, and what it made selected in the panels

  32. Replicate, from Insert > Replicate: id elbowBolt, connector seat.

    Replicate it onto the upper link's boltFace connector.

    Model a desk robot arm, step 153: Replicate made, and what it made selected in the panels

  33. Insert component, from Insert > Insert component: id elbowNut, part nut.

    Insert a nut for the elbow.

    Model a desk robot arm, step 154: Insert component made, and what it made selected in the panels

  34. Replicate, from Insert > Replicate: id elbowNut, connector seat.

    Replicate it onto the upper link's nutFace connector.

    Model a desk robot arm, step 155: Replicate made, and what it made selected in the panels

  35. Insert component, from Insert > Insert component: id wristBolt, part screw.

    Insert a screw as the wrist bolt, 8 by 30 mm.

    Model a desk robot arm, step 156: Insert component made, and what it made selected in the panels

  36. Replicate, from Insert > Replicate: id wristBolt, connector seat.

    Replicate it onto the forearm's boltFace connector.

    Model a desk robot arm, step 157: Replicate made, and what it made selected in the panels

  37. Insert component, from Insert > Insert component: id wristNut, part nut.

    Insert a nut for the wrist.

    Model a desk robot arm, step 158: Insert component made, and what it made selected in the panels

  38. Replicate, from Insert > Replicate: id wristNut, connector seat.

    Replicate it onto the forearm's nutFace connector.

    Model a desk robot arm, step 159: Replicate made, and what it made selected in the panels

  39. Insert component, from Insert > Insert component: id baseScrews, part screw.

    Insert a screw for the base, 5 by 9 mm.

    Model a desk robot arm, step 160: Insert component made, and what it made selected in the panels

  40. Replicate, from Insert > Replicate: id baseScrews, connector seat, offset -2.

    Replicate it onto the base's bolts connector, 2 mm down into the counterbores. One copy lands in each of the four holes.

    Model a desk robot arm, step 161: Replicate made, and what it made selected in the panels

  41. Insert component, from Insert > Insert component: id palmScrews, part screw.

    Insert a screw for the gripper's cover, 3 by 8 mm.

    Model a desk robot arm, step 162: Insert component made, and what it made selected in the panels

  42. Replicate, from Insert > Replicate: id palmScrews, connector seat, offset -1.5.

    Replicate it onto the gripper's screws connector, 1.5 mm down, one in each corner.

    Model a desk robot arm, step 163: Replicate made, and what it made selected in the panels

  43. Insert component, from Insert > Insert component: id jawScrewsA, part screw.

    Insert a screw for the first jaw, 3 by 10 mm.

    Model a desk robot arm, step 164: Insert component made, and what it made selected in the panels

  44. Replicate, from Insert > Replicate: id jawScrewsA, connector seat, offset -1.5.

    Replicate it onto the first jaw's screws connector.

    Model a desk robot arm, step 165: Replicate made, and what it made selected in the panels

  45. Insert component, from Insert > Insert component: id jawScrewsB, part screw.

    Insert a screw for the second jaw.

    Model a desk robot arm, step 166: Insert component made, and what it made selected in the panels

  46. Replicate, from Insert > Replicate: id jawScrewsB, connector seat, offset -1.5.

    Replicate it onto the second jaw's screws connector.

    Model a desk robot arm, step 167: Replicate made, and what it made selected in the panels
Model a desk robot arm, after step 167

Move the arm​

The joints read five parameters of the assembly: yaw, shoulder, elbow and wrist in degrees, and grip in millimetres. Each has a range, so select one in the Features panel and drag its slider in Properties: the arm moves while you drag.

Select a link component to give it other values for its document's parameters, such as a longer length. Both links come from one document, and each keeps its own values.

What you made​

  • Parts that reuse documents. The screws are one document inserted many times, each at its own diameter and length, and both arm segments are one link document at two sizes.
  • Connectors. Every place a part attaches is a connector on a face or a hole. Joints and replicates name connectors, not coordinates, so they follow the parts when sizes change.
  • Joints with limits. The turntable, the shoulder, the elbow and the wrist turn about their axes and the jaws slide, each within the range its joint allows, while the gripper is fastened to the wrist.

How the Designer works explains documents, connectors and joints in more depth.

Verified against the product in October 2026