Showing posts with label Science. Show all posts
Showing posts with label Science. Show all posts

Thursday, October 17, 2019

Linear Actuator

We just learned about the Rack and Pinion gears.

Another type of thing used in machines is a Linear Actuator.

The word actuator really just means "mover" and there are lots of types of actuators out there.
Linear means moving in a straight line.

So a linear actuator is a type of machine that moves something in a straight line.
We learned before about rotors that spin around in circles in electric motors.
So this is different because it might be moving a rod up or down, back or forward but in a straight line.

Sometimes this is done by having a bolt or screw that has lines on it, and then a nut spinning around on the screw that makes the screw go up and down.
This is a roller screw linear actuator.

(from: wikipedia - linear actuator)

Kid Facts - Blast from the past: Bellifortis Rockets

Thursday, October 10, 2019

Rack and Pinion

We just learned about the Air Gap in a motor.

Another type of thing used in machines is the Rack and Pinion.

A pinion is a gear, which we learned is a circle with teeth on the end.
The rack is a long flat line that has teeth on it, that match up with the gear.

When the gear spins around, it goes along the rack one way or the other.
These can be used as pinion wheels for something like a train that goes along a rack track, or sometimes as a pinion wheel that climbs up and down a pole that has a rack on it.

(from: wikipedia - rack and pinion)

Kid Facts - Blast from the past: Shock Diamond

Thursday, October 3, 2019

Air Gap

We just learned about the Electromagnet.

Another part of the electric motor is the Air Gap.

We learned that the rotor is the part that spins around in the middle, and the stator is the part that is wrapped around it.

The very small space between the rotor and the stator is the air gap.

The smaller the air gap, the better the electric motor will work, but it also needs to be enough space that the rotor won't hit the stator as it is spinning around.

(from: wikipedia - electric motor)

Kid Facts - Blast from the past: Multistage Rocket

Thursday, September 26, 2019


We just learned about the Windings.

Another part of an electric motor is the Electromagnet.

An electromagnet is a bunch of wire wrapped around a pole, and the wire has electricity going through it.
The electricity and the winding of the wire creates an invisible field that can be used to charge or move metals.

In an electric motor, the electromagnet is what helps spin the rotor around inside the stator using electromagnetism.

(from: wikipedia - electromagnet)

Kid Facts - Blast from the past: Lift

Thursday, September 19, 2019


We just learned about the Stator in an electric motor.

Another part of an electric motor is the Windings.

These are the metal wires that are wrapped around the stator or the rotor.
They are wrapped in loops around and around, and when electricity goes through these wires it creates something called an electric or magnetic field that can spin the rotor around.

This works kind of like magnets that can move metal without even touching them.

(from: wikipedia - electric motor)

Kid Facts - Blast from the past: Air Resistance

Thursday, September 12, 2019


We just learned about the Rotor shaft that spins inside an electric motor.

Another part of an electric motor is the Stator.

This is the circle hole that the rotor goes into when it is spinning.

Usually the stator has something like an electromagnet in it that is used to make the rotor spin around.
The stator doesn't move, and the rotor spins around inside it.

(from: wikipedia - stator)

Kid Facts - Blast from the past: Ballistics

Thursday, September 5, 2019


We just learned about the Electric Motor.

In the motor, the spinning pole or shaft in the middle is called the Rotor.

The electric motor spins the rotor around, and then the rotor is connected to other gears or pulleys to use the spinning to move other things.

(from: wikipedia - rotor (electric))

Kid Facts - Blast from the past: Inertial Navigation System

Thursday, August 29, 2019

Electric Motor

We just learned about the Bearing.

One type of motor used for a lot of things is an Elecric Motor.

This motor usually has some electric coils wrapped around a metal pole, spinning around inside a tube.

Some electric motors use the tube to force the pole to spin, and others take the energy from the spinning pole and use it to charge up electricity from the tube around it.

(from: wikipedia - electric motor)

Kid Facts - Blast from the past: Reaction Control System

Thursday, August 22, 2019


We just learned about the Axle.

Another part of machine work is a Bearing.

This is something that lets one part of a wheel spin around without moving another.
Like on a fidget spinner, you can hold the middle of it and the outside will spin around.
Or like a front bicycle wheel, the wheel will spin around the hole in the middle where the front handlebar is attached.

Usually this is done using ball bearings, which are tiny little balls covered in slimy grease.
On the outside is one metal cylinder, then a bunch of ball bearings, and then a smaller inside cylinder.

The outside cylinder can spin while the inside one is stopped, or the other way around.

(from: wikipedia - bearing (mechanical))

Kid Facts - Blast from the past: Attitude Control

Thursday, August 15, 2019


We just learned about the big long spinning pole called the Shaft.

Another part of machines is an Axle.

An axle is a long spinning pole like a shaft, but it is connected to wheels on either side.
It is also usually used to help hold up something like a car or a train.

Sometimes the axle doesn't spin but the wheels do, kind of like on a bike.
When a bicycle's wheel spins, the metal post inside the wheel does not spin.
This is usually called a spindle instead of an axle.

Cars and trucks are sometimes talked about by how many axles they have.
This really means how many sets of wheels across from each other are there.
So a normal car would be 2 axles, but a big semi truck might have 5 or more axles on it to help spread out the weight carried by each axle.

Sometimes they have more than one set of wheels on an axle to help hold the weight, but that still only counts as one axle.

(from: wikipedia - axle)

Kid Facts - Blast from the past: Inertial Measurement Unit (IMU)

Thursday, August 8, 2019


We just learned about the Pulley.

Another part of a machine is a Shaft.

A shaft is a long pipe, rod or pole that is on the inside of some kind of bigger spinning wheel.
This can be part of a gear, sprocket or pulley.

When the gear spins around, it turns the pipe.

In some machines, the pipe is used to move something else farther away from the gear.
Like in a windmill, the big wheel outside that is moving has a long shaft attached to it.
The shaft goes into the building where it is hooked up to other gears to turn them and do something useful like grid up corn into flour.

When the windmill turns, the shaft spins, and the gears inside spin and do the work.

A car also has a shaft. When the car burns up gas it makes a shaft spin which then connects to other shafts that turn the wheels.

(from: wikipedia - shaft (mechanical engineering))

Kid Facts - Blast from the past: Airspeed Indicator

Thursday, August 1, 2019


We just learned about the Sprocket that has teeth like a gear, but is made for a chain.

Another type of wheel that is used in machines is a Pulley.

Just like a gear or sprocket it is a wheel that spins for a machine, but the outside of a pulley does not have any teeth.
It has a cable, rope or belt around it that spins around the wheel.

Sometimes a pulley wheel is flat, and sometimes it has a groove for the rope to try and hold the rope or cable in the right place.

(from: wikipedia - pulley)

Kid Facts - Blast from the past: Spacecraft Magnetometer

Thursday, July 25, 2019


We just learned about the Gear.

Another piece of a machine is a Sprocket.

This is a wheel with teeth that looks a lot like a gear, but it is made to hook into a chain or a track.
If you look on a bicycle you will see a chain hooked to a wheel with teeth.
When you move the pedals it turns the wheel, which moves the chain, which turns the bike wheels and makes it go.
The wheel with teeth hooked to your pedals is a sprocket.

Sprockets are also used in things like tanks, or in other big machines.

(from: wikipedia - sprocket)

Kid Facts - Blast from the past: Gyroscope

Thursday, July 18, 2019


We just learned about the Motor or engine that makes things move.

One very important part of most engines is the Gear.

Gears are wheels that have teeth on the end, and usually a hole in the middle.
The teeth on the end can match up with other gears that also have teeth.
So when one gear moves, it also turns the other gear.

If there is a big wide gear that is moving very slow, it can be hooked to a small gear that will spin very fast.
Or it can be hooked to a gear that is sideways, to change the direction of the movement.

Gears are in everything from car motors to clocks to bicycles.
Pretty much everything with moving parts uses at least one gear to help control the movement made by the energy!

The teeth on gears are called "cogs", and gears are sometimes called cogwheels.
Sometimes people will even refer to themselves as a "cog in the machine" meaning that they are just one part of a bigger machine that makes things work.

(from: wikipedia - gear)

Kid Facts - Blast from the past: Rockets - Star Tracker

Thursday, July 11, 2019


We just started learning about Machines.

One of the most important things about a machine is the Motor, also sometimes called the engine.

The motor is the thing that takes some type of energy and turns it into movement.
Like a car's engine takes in gas, and then the engine burns the gas to turn it into movement that makes the car go.

Electrical motors can take electricity from a plug or a battery and use that to move something like a toy or a fan.

There are even types of motors that use steam, air, liquids or coils like toys that you wind up and they walk around.

Anything that takes in energy and then makes something move is a motor.
Really you can even think of our human bodies like engines that take in food and make our muscles move!

(from: wikipedia - steam engine)

Kid Facts - Blast from the past: Accelerometer

Thursday, July 4, 2019


We've learned a lot about the science of forensics that detectives use to solve crimes.

Another type of science is the study of Machines, which are the things that make the world move.

This could be anything from a car that is driving down the street to a windmill that takes wind power and turns it into energy.

There are many types of machines in the world, and there are lots of jobs for people who work with machines.
One type of job for working with machines is a mechanical engineer.

These people help figure out how to build machines and how to use them to build the things we need in our lives.

Another types of job is a machine operator, like the people who use the machine to do work.
This could be someone driving a big bulldozer, or someone working in a big building using a machine to cut or lift things.

Sometimes our machines break down and we need people to fix them.
There are lots of people working those jobs too, like a mechanic that looks at a car when it isn't working any more and has to figure out how to get it running again.

There are so many machines in our world that we need a lot of smart people to help make them work!

(from: wikipedia - mechanical engineering)

Kid Facts - Blast from the past: Altimeter

Thursday, June 27, 2019

Fire Investigation

We just learned about how Tire Skid Marks can help show what happened in a car accident.

Another type of forensic science is Fire Investigation.

After a big fire happens, the forensic scientists will go into the burned building or car, and look for evidence.
They look for things to tell them what may have started the fire.

There are lots of accidents that can start fires, like stoves or electrical plugs, or even magnifying glasses.

But sometimes bad people start fires either to hurt someone or to burn down a building they don't like.
When someone starts a fire like that on purpose it is called arson.

The scientists can tell from the different kinds of chemicals in the burned building or from the way the flame burned how it started and maybe even tell if it was an accident or on purpose.

(from: wikipedia - arson)

Kid Facts - Blast from the past: GNC - Guidance, Navigation, and Control

Thursday, June 20, 2019

Tire Skid Marks

We just learned about the Forensic Podiatry.

Another part of forensic science is Tire Skid Marks.

These are the marks left on roads from tires.
Sometimes cars can leave these marks if they are going really fast, taking a sharp turn, stopping very fast, or if there is an accident.

The marks on the road usually look like one of three kinds:

- acceleration marks: These are when someone goes from slow to really fast and the tires are just spinning.

- braking marks: These are when someone hits the brakes and their tires lock up and slide.

- yaw marks: If the car slides sideways either on a turn or because they hit something.

When there is a car accident, the police can look at the skid marks to figure out how the crash happened.

(from: wikipedia - skid mark)

Kid Facts - Blast from the past: Gimbaled Thrust

Thursday, June 13, 2019

Forensic Podiatry

We just learned about the Forensic Epidemiology, trying to prove what causes things like diseases or accidents.

Another part of forensics is Forensic Podiatry.

Podiatry is the study of feet, so this means looking at a person's foot to figure out evidence.
This might be checking to see if a footprint matches their bare feet, or it might be looking at a shoe footprint and trying to find out if that person's foot fits into that shoe.

(from: wikipedia - foot)

Kid Facts - Blast from the past: Rocket Thrust Vectoring

Thursday, June 6, 2019

Forensic Epidemiology

We just learned about Forensic Entomology, looking at evidence of bugs!

Another part of detective science is Forensic Epidemiology.

This is the science of looking at someone who is sick or injured, making a guess as to why it happened, and then trying to prove that the guess was right or wrong.

A lot of times people get sick or injured, and we think we know what caused it.
If someone has really bad breathing problems, detectives can look around for bad chemicals in the house, and then do some tests to see if that was really what caused their problems or if maybe they were a smoker or something else.

When a person gets into a car crash and then has neck problems, the science of epidemiology helps prove whether or not their neck problems were because of the car crash or if they would have had the same neck problems from something else.

This type of science is very important, because if scientists can prove that something is bad and causes sickness or injury, then things like bad chemicals can be made illegal, cars can be changed to have better safety, medicines and surgeries can be proven to be good or bad.

(from: wikipedia - forensic epidemiology)

Kid Facts - Blast from the past: Fire Arrow