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HamiMiami's Lego Page
Featuring the MindStorms SCOUT

January 7th, 2001

Light Seeking Missile Launcher

For Christmas 2000 my wonderful wife bought me a Robotics Discovery Set.

After tiring of the sample projects I wanted to see what I could do with the built-in programs.

This model uses one motor to rotate in place until it detects a bright light source (I use a flashlight.).  It then uses the other motor to fire the missle at the light source.

The white gear seen on left side of the launcher is part of the gearshaft connected to the cam on the opposite side.

For the missile launcher mechanism I modified a portion of the alarm from the sample projects that come with the kit.

This view shows the wiring.

TOUCH A & B are wired to each other and then a single touch sensor activated by the cam when the missile fires.  This causes both motors to brake thus stopping the model after the missile fires.

This is a bottom view showing the differential used to rotate the launcher in place with a single motor.
Here's a close-up view of the launcher mechanism.  Note the touch switch (yellow) on the left.  This is to stop the model after the missile fires. The cam rotates clockwise and should be positioned as show before pressing RUN to activate the launcher.

NOTE:  The scout seems to keep motors shorted (brake mode) when turned on and not running.  Turn the Scout off before manually positioning the cam as shown.

This view shows the built-in program settings for the launcher model.

MOTION: Loop B
(to rotate the motor in place)

TOUCH: Brake
(stop both motors after missile is launched)

LIGHT: Avoid
(Launches the missile when a strong light source is detected)

FX: BLANK
(Make sure BUG mode is NOT selected or else the "bug dance" will launch the missile unexpectedly)