Robotic Arm Lab — Chapter 3 (Frames + Axes)

Robotic Arm Lab

Chapter 3 — Frames & Axes (World vs Local)

Active Frame

World / Base / Joint / End-effector

Show World Axes

Global X,Y,Z

Show Robot Local Axes

Frames attached to joints

Show Tool Axes

End-effector frame

Easy rule: World frame is fixed. Local frames are glued to joints — so they move with the arm.

J1 (Base Turn)

Angle: -180° to 180°

J2 (Shoulder)

Angle: -60° to 120°

J3 (Elbow)

Angle: 0° to 150°

Speed

Slow = see axes clearly

Smooth Motion

Easing / no easing

Keys: R reset • F cycle frames • H human on/off

Show Human Arm

Comparison

Human View

Split/Ghost

Alive Amount

Subtle realism

Muscle Lag

Soft delay

Human arm is never perfectly rigid. Small breathing + tiny hand wobble makes it feel real.

Frame: —

EE pos: (—, —, —)

EE ori (yaw/pitch/roll): (—, —, —)

Chapter 3: Frames & Axes

Frame = a tiny coordinate system (X,Y,Z arrows).

World frame is fixed. Local frames are glued to joints, so they move with the robot.

Hover parts to see easy explanations. Move joints and watch how frames rotate.

Selected: None

Hover a part in 3D. Click to lock selection. Press R to reset.

Try this:

Select Joint-2 Frame. Now move J2. See how the axes rotate WITH the joint. Then select World Frame—it stays fixed.

Kid-level math:

Position = (x,y,z). Orientation = “which direction the tool points”.
Robot kinematics = chaining frames from base → joints → end-effector.