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Joints in R3: hinges, sliders and welds, by hand

1:10 · 2026-11-05

In the R3 editor, a fixed hook and a weight beside it: add a Joint Revolute, set Body 1 to the hook and Body 2 to the weight, Anchor 2 X to -2 and the Axis to 0, 0, 1, and start physics: a pendulum. Limits of 0.785 radians stop it at 45 degrees each way; a motor at 3 radians a second turns it round. Narration: AI voice.

Chapters

  1. 0:00 A fixed hook and a weight: add a Joint Revolute
  2. 0:12 Body 1 is the hook, Body 2 the weight
  3. 0:23 The anchor and the axis
  4. 0:35 Start physics: a pendulum
  5. 0:42 Limits: stop at 45 degrees each way
  6. 0:57 A motor turns it round

Transcript

0:02 A fixed hook, and a weight beside it. Open Create, and add a Joint Revolute, a hinge.

0:12 In the Inspector, open Joints, and the new joint. Body 1 is the hook. Body 2 is the weight.

0:23 The pivot, seen from the weight, is two metres to its left. The axis points at you, so it swings on the screen.

0:35 Start physics. A pendulum.

0:42 Now tick Limits Enabled, and stop it at 45 degrees each way. That's 0.785, in radians.

0:52 Start again. Now it stops, like a door.

0:57 Limits off, motor on, at three radians a second.

1:01 Start, and the motor turns it round and round.