Model a desk robot arm: the gripper

The gripper's palm carries the jaws in two rails. Pockets cut the rails, and a fillet blends the neck into the palm so the two read as one cast piece.

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.

70. New part, from File > New part: name Gripper.

    The gripper housing carries two jaw rails, four cover screws and a neck that is blended into the palm.

    

71. Sketch, from Insert > Sketch: id outline, on the XZ plane, start -29, -16.

    Sketch the palm's outline on the ground plane: a rounded rectangle, 70 by 32 mm.

    

72. Extrude, from Insert > Extrude: id palm, profile outline, distance 16.

    Extrude the outline 16 mm.

    

73. Fillet, from Insert > Fillet: id frontRim, body palm, radius 2.

    Round the top face's rim by 2 mm.

    

74. Fillet, from Insert > Fillet: id backRim, body palm, radius 2.

    Round the bottom face's rim the same way.

    

75. Sketch, from Insert > Sketch: id guideA, on the end face of palm, start -31, -4.

    On the top face, sketch the first jaw's rail: a slot 25 by 8 mm in from the left end.

    

76. Pocket, from Insert > Pocket: id railA, profile guideA, body palm, distance 5.

    Pocket the rail 5 mm deep.

    

77. Sketch, from Insert > Sketch: id guideB, on the end face of palm, start 6, -4.

    Sketch the second jaw's rail, in from the right end.

    

78. Pocket, from Insert > Pocket: id railB, profile guideB, body palm, distance 5.

    Pocket it 5 mm deep too.

    

79. Hole, from Insert > Hole: id screws, body palm, on the end face of palm, diameter 3.

    Drill four counterbored holes for the cover screws, one near each corner.

    

80. Sketch, from Insert > Sketch: id mount, on the start face of palm.

    On the bottom face, sketch the neck: a circle 24 mm across.

    

81. Boss, from Insert > Boss: id neck, profile mount, body palm, distance 6.

    Raise the neck 6 mm as a boss.

    

82. Fillet, from Insert > Fillet: id neckBlend, body palm, radius 3.

    Round the edge where the neck meets the palm by 3 mm, so the two blend into one.

    

83. Part properties, from the Properties panel: id palm, name Gripper, material abs, color #eceef1, metallic 0, roughness 0.4.

    Name the part Gripper: white ABS, like the shoulder.

    

84. Add connector, from Insert > Add connector: part palm, id mount, on the end face of neck.

    Add a connector on the neck's end. The gripper is fastened to the wrist's flange there.

    

85. Add connector, from Insert > Add connector: part palm, id jawA, on the side face of railA, origin -6, 13.5, 0.

    Add a connector at the end of the first rail, where the first jaw's carriage slides.

    

86. Add connector, from Insert > Add connector: part palm, id jawB, on the side face of railB, origin 6, 13.5, 0.

    Add a connector in the second rail for the second jaw, facing the other way.

    

87. Add connector, from Insert > Add connector: part palm, id screws, on the end face of palm, axis the wall face of screws.

    Add a connector on the top face, its axis along the screw holes, for the cover screws.