LEGO MY PANCAKE
The LEGO Pancake Bot created by Miguel Valenzuela is a work in
progress, designed to make pancakes in shapes. Two empty ketchup
bottles serve as dispensers on an aluminum protected track, and a three-axis Computer Numerical Control (CNC) handles the movement with
Python NXT — a scripting language for LEGO projects. It uses the Z
coordinate as the pancake batter dispenser control.
The Pancake Bot is made up of the following parts:
1. A set of linked base plates with three parallel tracks snapped on.
One track has a bunch of Technic Gear Racks (1 x 4) riding along the
top which makes up the X axis.
2. A moveable bridge that holds one NXT motor on one side and
has free rolling wheels on the other. The top of the bridge uses two tracks
covered with gear racks that holds the pancake Batter Dispenser Unit (BDU). This
track allows for Y axis control.
3. A carrier gantry on top of the moveable bridge that rides on the gear racks
and holds the BDU.
4. As mentioned, the BDU consists of two ketchup bottles cut in half and
glued together so you have two open ends. This allows you to change the nozzle
size on the bottom and allows for input of compressed air on top.
5. A Compressed Air Dispersal Apparatus (CADA) that consists of an NXT
motor, two pneumatic cylinders, a tank, and a bi-directional flexible switch which
allows for the switch to be flipped based on which direction the NXT motor
turns. As the motor turns, the cam changes the flexible switch every time it
rotates. In the initial turn, the switch is flipped and stops, and then continues to
flex out of the way of the rotating cam. When the motor turns the other way, the
cam catches the switch, flips it back, and changes the direction of the airflow. It
continues to flex as the cam passes over it. This allows for air to be compressed
when the motor turns clockwise, and then the air to be released when the motor
Valenzuela designed the bot this way because he only had three NXT motors
and needed a way to change the direction of the air flow while at the same time, compressing the air. Go to
http://makermig.blogspot.com/2011/06/how-pancake-bot-works.html for more details and videos.
DIGGER TEARS THINGS UP
The Digger D- 3 is the most recent addition to my own personal
list of robots not to stand in front of. It's a mine-clearing robot, and not
the sort of mine-clearing robot that pokes around with a metal
detector. Instead, it simply sucks it up and tells the landmines to bring it.
At the front of the D- 3 is a giant spinning metal pulverizer of death
which has Tungsten hammers that beat down a quarter meter into the
ground, turning everything they touch into mulch. This includes landmines, and although the mines do tend to blow up before
getting shredded, the robot hardly seems to notice.
An operator commands Digger from a safe distance using a remote control unit. The hull of the robot is made up of
hardened steel plates in a V shape to help limit any damage from antitank mines and unexploded shells of sizes up to 81 mm.
The D- 3 has been able to successfully ingest mines containing as much as eight kilograms of explosive — which is nothing to
sneeze at. The only potentially vulnerable spots are the air intakes which are themselves protected from flying shrapnel by
At full throttle, the D- 3 can reliably clear a comforting 100 percent of landmines from the ground at a rate of 1,000 square
meters per hour (about 10,000 square feet per hour), while also divesting the land of any unwanted shrubbery and unlucky
Cool tidbits herein provided by Evan Ackerman at www.botjunkie.com, www.robotsnob.com, www.plasticpals.com, and other places.
24 SERVO 09.2011