Make a wheel spin

Goal: make a part keep turning until it's told to stop, like a wheel, fan or handwheel.

Steps

1. Open ALF > Interactivity > Kinematic Editor Tool.

2. 1 Object: drag the machine from the Hierarchy into Drag object here ->.

3. 2 Part: click the wheel in the Object hierarchy list.

4. 3 Movement: press Add Rotational Motion Script.

5. Under Rotational Motion Settings, set:

   Field	What to enter
   Rotation Mode	Continuous
   Rotation Axis	The axis the wheel turns around: X, Y or Z.
   Speed	How fast it turns, in degrees per second. 360 is one full turn per second.

6. Check the cyan line and sphere in the Scene view. They should run through the centre of the wheel. If not, see Turn a part around a hinge and put the marker at the wheel's centre.

7. Add buttons to start and stop it. See Add buttons that move the parts.

8. Save the scene with Ctrl+S.

Result

Started in the positive direction, the wheel turns one way; in the negative direction, the other way. It keeps turning until Stop is pressed.

Good to know

• Limits don't apply in Continuous mode, so the limit fields are hidden.
• It can run as long as you like. The angle is kept between 0° and 360°, so it doesn't drift over a long lesson.