Limited Availability due to COVID19! Click Here For More!

Buildologie / Simple Machines

Though these devices were also used in machines in Leonardo's time, he experimented with them and made changes to improve how they worked. He also combined them in many exciting new ways to create machines and inventions that had never been seen before.


The process of creating solutions to human problems through creativity and the application of math and science knowledge.


A man-made device, usually driven by a motor or engine, with a system of interrelated parts that work together to perform a task.

Simple Machine

Anything that has few parts and makes it easier to do a task.These devices were all in common use for centuries before Leonardo's time. Each one makes work easier to do by providing some trade-off between the force applied and the distance over which the force is applied.

Complex Machine

A combination of two or more simple machines.


A stiff bar that rotates around a fixed point and makes it easier to lift a load or apply a force. A lever is a stiff rod that rotates around a pivot point. Downward motion at one end results in upward motion at the other end. Depending on where the pivot point is located, a lever can multiply either the force applied or the distance over which the force is applied.


A wheel with grooved edges for ropes that is used to change the direction of a pull and make it easier to lift a load. A single pulley simply reverses the direction of a force. When two or more pulleys are connected together, they permit a heavy load to be lifted with less force. The trade-off is that the end of the rope must move a greater distance than the load.


A disk or circular frame that revolves on an axle.


A pin, pole, or bar on or with which a wheel revolves.


Two differently sized wheels attached to the same axis that are used to make circular motion easier. In this machine a wheel or spoke is locked to a central axle so that when one is turned the other must turn. A longer motion at the edge of the wheel is converted to a shorter more powerful motion at the axle. In reverse, a short powerful force at the axle will move the wheel's edge greater distance.


Inclined planes wrapped around a cylinder that are used to raise and lower objects and hold objects together. A screw is a central core with a thread or groove wrapped around it to form a helix. While turning, a screw converts a rotary motion into a forward or backward motion.


Two inclined planes joined back to back to form a sharp edge that are used to change the direction of a force and often result in the splitting of objects. A wedge converts motion in one direction into a splitting motion that acts at right angles to the blade. Nearly all cutting machines use the wedge. A lifting machine may use a wedge to get under a load.

Inclined Plane

A surface slanted upwards that lowers the effort needed to lift a load.


A wheel with teeth around the edge that is used to turn other gears and change the direction, speed, and force of circular motion. Gears are toothed or pegged wheels meshed together to transmit motion and force. In any pair of gears the larger one will rotate more slowly than the smaller one, but will rotate with greater force. Each gear in a series reverses the direction of rotation of the previous gear.

Bevel Gears

Gears that mesh at an angle change the direction of rotation.

Worm Gear

A worm gear is a combination of a gear meshed with the threads of a screw. This combination changes the direction of turning motion by ninety degrees. Worm gears also decrease the speed of turning from screw to gear and increase its force.

Rack and Pinion

a single gear, the pinion, meshes with a sliding toothed rack. This combination converts rotary motion to back and forth motion. Windshield wipers in cars are powered by a rack and pinion mechanism. A small pinion at the base of the wiper meshes with a sliding rack below.


A cam is a wheel with shaped bumps on it. Cams are often connected to rods, levers, or springs. In the gravity trip hammer shown here, the bumps on the turning cam push down on the end of the lever making it raise the hammer again and again.

Crank and Rod

the crank is a wheel with a pivoting arm attached near its edge. The arm is attached by a hinge to a rod. When the crank turns, the rod is pushed back and forth. Alternatively, if the rod is pushed back and forth at the right speed, the crank will turn. The crank and rod shown here is part of giant steam engine.

Chains and Belts

A chain or belt connects two separated wheels so that one turns, the other will turn in the same direction.


A ratchet is a device that allows a wheel to turn in only one direction. The ratchet wheel has specially shaped teeth. A bar on a pivot called the "pawl" is fixed above the ratchet wheel. The pawl slides over the teeth of the ratchet in one direction, but blocks the motion of the teeth if the wheel turns in the other direction.

Buildologie / Robotics

An arbitrary decision is one that is not made analytically, but is based on personal taste or style. Arbitrary decisions in robot design are normally about characteristics that do not affect how the robot performs, such as color.

A robot is said to be autonomous if it is programmed to operate on its own, with no remote control.

Special recognition for achievement determined subjectively by judges, using data gathered in judging sessions, and other observations throughout a tournament.

When you hear someone else’s idea about something before you have had a chance to think about it for yourself, you are biased .When you are biased, your capacity for original thought is reduced.

This is a process for generating many varied ideas. One method: a person stands at the front of the room and records everyone’s ideas until no one can think of any more ideas. What seems like a crazy idea at first is often seen to have possibility later.

An opportunity for judges to gather additional information about a team. Can be formal presentations, informal interviews in the pit area, or through observations on the competition field.

Center of Mass
An object’s center of mass is an internal spot under which the object could be balanced.

Each year FIRST LEGO League focuses on a set of real-world problems facing scientists and engineers. The Challenge has two parts: the Robot Game and the Project.


This is the length around the edge of a circle.

Clarifying the Problem
It is important in any problem solving exercise to hear the wording of the problem for what it is, break the problem down, and focus on the real desired outcome. For example: Someone hands you a tennis ball and challenges you to get the ball in a crate on the ground about 80 feet away. Do you take the challenge? Do you ask how many bounces are allowed? Do you worry if you can throw that far, or how your aim is, or how many shots you get? No! You clarify the problem in terms of the desired results, walk to the crate, and drop in the ball .In this example, the actual problem was “get the ball in the crate.” No one said it had to be thrown. No one said it had to be done from where you were standing. Do not add unnecessary restrictions to the solution approach, and do not take it for face value that you can only do things as they have been done before.

A process under control is one for which you can set parameters, and predict the process outcome. Systems with a lot of variability in them are not under control.

Dead Reckoning
A robot is said to navigate by dead reckoning if it is relying on sensors that cannot detect features of the playing field, or if it is relying on no sensors at all.

The period when judges discuss team achievements and determine which teams are most deserving of receiving FLL awards.

Drive vs. Driven
The drive component is the one from which torque is coming, and the driven component is linked to the load.

Changing over time.

An efficient solution is one that works without wasting time, material, or energy.


The ability to do work.

Engineers study the sciences and use knowledge to manipulate energy and materials to solve problems and to produce the products and systems we use every day.

Engineering solution
A method or act of solving a problem using scientific and mathematical principles to design, manufacture, and develop operations of efficient and economical structures, machines, processes, and systems.

Experimentation is the process of learning by trying different things. With enough knowledge and work, a scientist or engineer can make predictions about what will happen under certain conditions. Sometimes it is easier to try each condition and see what happens directly. For example, a chemist may be able to analyze the composition of two different types of paint and figure out which one will dry first, but the easier way to get the information would be to just try the paints next to each other, aim a fan at them, and touch them every once in a while.

Failure is a temporary situation and a learning tool we encounter when things do not work as expected. If we take a lesson from every failure and never quit, sooner or later things will work out. True failure only comes when we give up .Feasible Can be done with the materials and knowledge available.

Results of an evaluation plus additional judge comments provided to a team after the tournament is completed.

Friction makes it difficult to slide surfaces on each other. The harder the surfaces are pressed together, the more friction there is between them. Friction also depends on the materials in contact. For example, ice slides on glass easily and rubber slides on ice easily, but it is hard to get rubber to slide on glass. When surfaces slide despite friction, energy is lost in heat and the surfaces also begin to wear out. LEGO axles are designed to spin freely with little friction, as long as they are not bound or bent. When building your robot, make sure that every axle turns freely, otherwise the motors will be working to fight friction instead of producing torque or speed, and your battery energy will be wasted.

Gear Ratio
The gear ratio of a set of linked gears is the big gear’s number of teeth divided by the small gear’s number of teeth (diameters work too). If the driven gear is the smaller one, you are “gearing up,” and if the driven gear is the bigger one, you are “gearing down.” Example: 16-tooth drive, 64-tooth driven . . . the system is “geared down, 4:1” (four to one) . In other words, if your robot is a vehicle and you gear it down, it will be strong like a tank with lots of torque at the wheels, but if you gear it up, it will be fast like a sports car with lots of speed at the wheels.

Gracious Professionalism
A manner that leaves everyone feeling valued and respected.

Ground Clearance
The height of the tallest object your robot can go over without touching it or jumping it is your robot’s ground clearance. If parts of your robot extend forward beyond its front axle and you want the robot to climb from a level surface to an inclined surface, it is important for the overhanging parts to have plenty of ground clearance.

A new idea or improvement on an existing idea. A solution that is not already in use by someone else.

A temporary failure that gets you measurably closer to a solution can be called iteration.

Judging Session
A set period of time during each tournament for each team to present information to the judges in the Project, Robot Design, and Teamwork categories. The format could be any combination of the following: formal presentation, a formal or informal question and answer session, or through observation while completing an activity.

A lever turns sideways force into torque (see TORQUE) . In the example of a wrench and a nut, you push sideways on one end of the wrench, and the other end twists the nut. In fact, the longer the lever you push on, the more torque you can get from the same sideways force. For example: hold a wooden 12-inch ruler level by pinching the first half inch. Now try the same thing with a wooden yardstick. The yardstick exerts nine times the torque on your fingers than the ruler does, because it is three times longer and three times as heavy.

A linkage is a sequence of parts that transmits force from where it is produced to where it is needed.

Any person who works with the team in her area of expertise

A job the robot can complete for points.


The parameters of a system are the things you can set to certain values to control the outcome.

Problem Solving Model
Whether the solution to your problem is a design, an object, a piece of information, or a process, the steps for finding a solution usually look the same: • Focus on the desired results, and clarify the problem in terms of those results .• Break up the problem into simpler parts if possible .• Brainstorm for solution ideas for each part .• Choose the two or three best solution ideas for each part and develop them in detail .• Mix and match the solution ideas into the best overall solution .• Test and improve the solution thoroughly .Project Research on a real-world problem and existing solutions related to the Challenge theme, creation of an innovative solution to the problem and sharing of the research and solution with others.

An example, model or something that serves to illustrate the qualities of an invention or creation.

Random means by chance only and not controlled. The more variability there is in a process, the more randomness there will be in the outcome. For example, it is harder to predict the outcome from rolling a six-sided die than a two-sided coin.

Based on what is real or practical although it may not presently exist.

The act of gathering information (verb) or information gathered (noun).

Reverse Engineering
Sometimes called benchmarking, this is the process of taking something apart and analyzing it to understand how it works.


Robots are a special class of machines, distinguishable by their human-like abilities to manipulate objects or move about, and the fact that they can perform different functions depending on how they are programmed .A robot is the solution to many precise, strenuous, monotonous, and sometimes dangerous challenge.

Robot Game
A series of tasks or missions to be accomplished by an autonomous robot designed and built by each FLL team.

A robust design or process is one that yields consistent results in spite of changing conditions. For example, if you practice in a room with a window, the lighting can be much different at 4:00 PM than it was at noon. In a robust design, the light sensor would be
placed and shielded so that the robot would not notice the differences in light.

A rubric is a chart composed of criteria for evaluation and levels of fulfillment of those criteria. It allows for standardized evaluation according to specified criteria .Scientific

A process based on gathering observable, empirical and measurable evidence subject to specific principles of reasoning. It is the collection of data through observation and experimentation, and the formulation and testing of hypotheses. Sometimes called the scientific process.

Scientific Research
Investigation or experimentation aimed at the discovery of new theories or laws and the discovery and interpretation of facts or revision of accepted theories or laws in the light of new facts.


Scientists study the world around them to learn how things happened and what is going to happen next. Their knowledge has accumulated over the centuries to formulate the sciences of physics, chemistry, geology, biology, astronomy, and so on .Solution A method or act of solving a problem.

A stable robot is shaped so that it does not fall over easily. Typically, flat, long, wide robots are stable. Tall, short, narrow robots are unstable. Be careful when designing with large wheels. They are a good way to boost ground clearance, but as your robot gets taller, it loses stability. Maintain stability by increasing robot width and length as robot height increases.


A subassembly is a portion of your robot that has a specific purpose, but can be taken off or put back onto the robot very easily.

An object under stress experiences internal forces that could result in the object deforming or breaking. Types of stress include:

 -Tension as a result of pulling
-Compression as a result of pushing
-Torsion as a result of twisting
 -Shear as a result of bending

Technical Terms
The specialized vocabulary of a field of study. These words have specific definitions within the field, which are not necessarily the same as their meaning in common use.

Technicians study the products and systems developed by engineers and are uniquely qualified to run and maintain them.

Technological Solution

A method or act of solving a problem using scientific knowledge and specific methods, materials, and devices.

In science, a mathematical or logical explanation, or a testable explanation of a set of occurrences, capable of predicting future events or observations of the same kind, and capable of being tested or proved false through experimentation or observation.

Torque is twisting force. Get a broom and hold it level, as if it were the handle of a shopping cart. Your left hand should be near the sweeping part, and your right hand should be at the very far right end of the handle. Now let go with your left hand, and try to keep the broom level. It is pretty hard, right? You just experienced torque. The broom exerts a counter clockwise torque on your right hand, and your arm exerts a clockwise torque to balance it. Torque is often exerted on shafts (like your right arm) by levers (like the broom). In turn, shafts exert torque on levers.

Torque-Speed Trade-Off

The longer a lever is, the farther you have to push its end to make it go around. To turn a 6-inch wrench once around, your finger will push sideways about 38 inches. For a 12-inch wrench, you would have to push 75 inches. It is the same for gears: a 16-tooth gear will go around twice for every time a 32-tooth gear does when they are meshed .Here is what this means: A small driven gear will spin faster than the gear driving it, but it will make less torque. A large driven gear will turn slower than the gear driving it, but it will make more torque.

To transport an object is to carry it to a new location. The need to transport objects is a common FLL Challenge problem. If your robot is designed to transport something, make sure to run tests over a variety of speeds and direction changes, and with a variety of obstacles, to make sure the carried object does not interfere with other robot functions and that the robot maintains possession of the object.

Universal Design
Products and environments that are usable by all people, to the greatest extent possible, without the need for adaptation or specialized design.


Variability in a system makes it hard to repeat outcomes. If you were asked to drop a piece of notebook paper into a trash barrel on the ground while you stood on top of a roof, it would take a long time, and you may never see the paper land in the same place twice . But if you crumpled it into a tight ball first, you would reduce the variability of the dropping process, and would probably make the shot in just a few tries. Think of variability sources like playing field flaws, lighting, battery power, wear, dirt, etc., and design your robot and your strategy robustly, to minimize the effects of variability.

The wheelbase is the distance between the extreme front and rear axles.

Computer Science/Software Programming/Coding

Software is the set of instructions or programs that tell a computer what to do. It is independent of hardware and makes computers programmable.

Software Development
According to IBM Research: “Software development refers to a set of computer science activities dedicated to the process of creating, designing, deploying and supporting software.”

Back to the top