Robot Overlord 3

How to record and play back a robot arm motion

By Dan Royer

How to record and play back a robot arm motion

Recording a robot arm while you move it live is a great way to "rough out" a motion for later refinement. In this guide you'll learn how to prepare, run, and stop live recordings. You'll also learn how to play them back.

Watch on YouTube

Step 1 Load a robot arm

  • Get your favorite robot arm file. Here is an AR4 is used as an example.

  • Extract the ZIP file. Inside it will be an AR4-3.RO file. Open the file in Robot Overlord.

  • Open the Editor tab: Click Windows > Editor, and drag the tab to arrange it where you want.

  • Tell the Editor which robot you're using: either....

  • ...click the Editor "..." button and select MarlinRobotArm OR

  • ...drag MarlinRobotArm from the Scene tab onto the "..." button.

  • Now you're ready to start recording.

Step 2 Moving with Forward Kinematics

  • Select the Limb Node. In this case it is called AR4.

  • Move each joint: turn the dials by either clicking and dragging (large moves) or rolling the middle mouse button (fine moves). This is Forward Kinematics.

  • Note:

    Do this while recording is on and gcode will be added to the editor window every time the interval elapses.

Step 3 Moving with Inverse Kinematics

  • Select the LimbSolver

  • Pin it, if you like.

  • Select the target (two different ways)

  • Toggle Move mode

  • Push and pull the gizmo.

  • Raise the maximum linear velocity. The arm will start moving towards the target. You can move the target in real time like a rubber band.

  • The Target To EE button will move the target to the End Effector, instantly stopping the arm.

  • The Goal Margin button controls how close the arm wants to get to the target. It is a sum of linear distance and rotation degrees.

Step 4 Playback

  • Note:

    I have created a short recording in the Editor tab using the previous steps.

  • Note:

    Make sure to stop the recording and turn off the Get + Lock

  • Set the LimbSolver > Linear Velocity to zero or the arm will keep trying to follow the target after every step of the recording.

  • Select the first line in the recording and press Send. Notice the arm jumps to the Forward Kinematic values in the gcode. Notice the caret moves to the next line.

  • Press Send until you are satisfied you have walked through the entire recording.

  • Edit and remix to taste. Bon appetit!

Complete

Now you can record and play back simple recordings of your robot arm. Huzzah!