MotorBlog Part 3: Problems With My Motor

I spent nearly three weekends building this motor, and mainly because I kept on making some really stupid errors.

Firstly, I originally built the field magnet wrongly, and ran out of wire the first time around. I had to buy another spool of magnet wire, wrapped it around again, and then realized that I was wrapping it incorrectly.

I also built it originally without much legroom for fixing it, making it difficult to alter:

Then there were times where I didn’t shave enough enamel off the magnet wire, and the electricity wasn’t able to flow correctly.

I also originally had too small of a spool.

It was building the commutator and the brushes, however, where I encountered the most problems. First of all, I originally used solder to attach the wire to the copper, but that ended up not working because there wasn’t enough contact between the copper and the wire:

Next, I originally made the brushes way too small. They would always get caught in the commutator and therefore stop the motion of the motor altogether.

My commutator used to have too much space between the two pieces of copper. This prevented the current from flowing into the copper from the brushes properly as the motor moved, which caused the motor to not be able to work at all. (Notice: The dimensions of the copper in my other post were matched to the correct lengths that I used in order to make the motor work). I also didn’t make the copper perpendicular to the nail heads, which interrupted the magnetic field.

Then, later on when I had the correct lengths of copper, I put some extra tape on it to make sure that it stuck. When it didn’t work, I took off the extra tape, and the motor worked perfectly. The moral of the story: Build your brushes and commutator correctly, and don’t use too much tape.

Finally, I originally made the spool stable using a heavy cork, which slowed the motor down.

MotorBlog Part 2: How My Motor Works

So, let’s move onto how I build my motor and how it works. My motor has the six parts that I mentioned in my earlier post: the armature, commutator, brushes, shaft, field magnet, and a DC power supply. I will be explaining how I built these six parts in detail throughout this post. The materials used were:

1. Strap iron

2. 200 feet of 24-gague magnet wire

3. Two 16-penny nails

4. Electrical Tape

5. Metal Rod

6. L-Brackets

7. A 6″ by 7″ wooden board (base)

8. A 6-Volt Battery

9. A Vise

10. Screws, washers, and everything that accompanies them (drills + screwdrivers)

11. Sandpaper

12. Some plastic-thing (see Field Magnet section)

13. 18-gauge single-strand lamp wire

The building process went as follows:

1. The Field Magnet

Firstly, I shaped a 6″ metal strip into thirds, and then bending the ends so that there is a 3″ difference between the two. Generally, this distance will vary from motor to motor depending on how big the armature is. Then, I wrapped wire around it. I used 24 gauge magnet wire, so I had to wrap it around 400 times. Make sure that there is little to no space between each round, and that the wires don’t cross over each other (it will disrupt the magnetic field if that happens). If you’re able to, I’d recommend using 14-16 gauge single-stand lamp wire instead of what I used, but I couldn’t find any, and I couldn’t find enough 18-gauge lamp wire as a substitute. I used a vice to hold the metal in place.

I also left some wire hanging off the ends, and sanded it down so it could make a connection. Piece of advice: IF YOU DON’T REMOVE THE ENAMEL, THEN ELECTRICITY WILL NOT BE ABLE TO FLOW. You can use a sharp blade to shave off the enamel, but I just used sandpaper.

Next, I had to find a way to attach the field magnet to the board. I went searching through my Dad’s supplies to find something, and found this:

I’m not entirely sure of what it is, but it managed to hold the field magnet down if I cut it like this:

And then screwed it into the board.

So, no complaints here.

2. The Armature/Shaft

Firstly, I cut two 16-penny nails down to a 2.5″ length, from the head of the nail down. I then taped them together, found the midpoint, and stuck a 6″ metal rod through it, leaving around 2″ to stick out the other side.

Next, I had to wind conductive wire around the taped nails. I used 24-gauge magnet wire for this job. Leaving some magnet wire on the end, I began winding next to the shaft, wond to the end of one nail, then back to the shaft, then back to the end of the same nail, then back to the shaft, and then did the same thing . Make sure that there is little to no space between the turns. Then, when I was finished, I cut the magnet wire, but left around 2″ of it behind, like I did earlier. I used my vice again to hold the armature in place. 

I also removed the enamel from the ends of the wire again, as I did before.

3. The Commutator

I cut two 1″ by 3/4″ copper strips, and on one end nailed holes into them. The holes will allow me to attach the magnet wire from the armature later on.

Then I had to make a cylinder with a 1/2″ diameter. I just wrapped electrical tape around the shaft until I got a diameter of that length.

After that, I attached the additional wire to the pieces of copper by looping it through the holes and then twisting them to keep them in place.

Then, I taped the copper strips to the cylinder of tape. I also took note of the small spaces between the two copper strips and made sure that they were parallel with the nails on the other end of the shaft. Make sure that the wire connecting the pieces of copper to the armature is taut; it would get in the way of the motor if loose.

4. Supports for Shaft and Brushes/Spool:

Firstly, the brushes. This is probably the most essential part of the motor, and it took me a very long time to get these right. In the final motor, the brushes were made out of 18-gauge lamp wire. I made the brushes long, so that the copper sticking out won’t get caught on the commutator. I then attached them to pieces of 2.5″ by .5″metal using tape, and screwed them into the board, leaving some copper on the top and bottom in order to have a completely functioning circuit (more on that later).

As for the supports, I used some L-brackets that I bought online that are around 3.5″ by 1.25″ and screwed them into the board, allowing enough height for the armature and enough space on the end to put the spool to pull a car. For the spool, I just used the magnet wire’s former spool, cut it down, and put some styrofoam in it to keep it steady.

5. Creating The Circuit

Remember all the additional wire that I left at the ends of the field magnet and the supports for the brushes? Well, that’s going to come into play here. Firstly, I connected some wire from the two ends of the battery, so that it looks like this:

I also included a switch in my circuit:

Then, I connected the circuit as follows:

I also put some tape collars on the ends of the shaft to keep it from moving back and forth. Now, my finished product looks like this:

MotorBlog Part 1: How Electrical Motors Work

Motors are one of the most useful devices that humanity has ever created. They power fans, electrical toothbrushes, the washer and dryer, the refrigerator, and even the computer that I am using at this very moment to publish this blog. One might think that building a motor might be difficult, but that is where most are mislead; it is actually rather easy to construct a motor as long as one has the right materials. Before I go into detail about how my own motor works, let’s talk about how DC electrical motors work in general.

Firstly, the magnets. Magnets are specific objects that consist of microscopic regions called magnetic domains. Not every substance has magnetic domains, but if these magnetic domains are aligned, then metals like iron, cobalt, and nickel become magnetized and create a magnetic field. 

If these domains are unaligned, then the object can not be used as a magnet.

This also explains why magnets have poles; to be more specific, a north pole and a south pole. The domains within a magnet all face in one direction, and therefore in order to become attracted to another magnet, the domains must be pointing in the same direction on that magnet as well. Think of it like cars on a highway. If all the cars are going in the same direction, then the highway functions like normal. If someone tries to drive in the opposite direction, then you’ve got a lot of people being repelled by this complete idiot and will try to move as far away as possible from that car. This also explains why poles are attracted to the opposite pole. Magnets act a lot like an electrical circuit; the electrons are always moving towards the protons, because protons are unable to leave the atom. Therefore, if you add more magnets to a singular magnet, the domains will always be positioned in one certain direction, and if you attach a positive pole to a negative pole, then you’ve made yourself a bigger magnet because the electrons are all flowing in one direction. If you try to attack two poles whose domains are moving in opposite directions, then you’ve got two magnets that do not want to attach to each other.

And yes, for those who are wondering; the earth itself is a magnet as well. Why else are the North and South Poles named the North Pole and the South Pole?

Furthermore, you can magnetize certain metals by making it come into contact with another magnet that already has its domains aligned, therefore causing the domains in the unaligned metal to all face in one direction and magnetize the metal. However, if one were to drop the magnetized metal or somehow damage it, the domains will most likely face in all different directions. This is where the difference between magnetized metals and permanent magnets comes into play. A permanent magnet is much stronger than a magnetized metal, because it is “permanently” a magnet; in other words, the magnetic domains always remain aligned, and the magnetic field is always intact.

Permanent magnets have their upsides and downsides. For one, when using a permanent magnet, you always have a magnetic field at your disposal, and if made correctly the magnet will be pretty strong. But what if you want to detach something from that magnet? You won’t be able to remove something attracted to a permanent magnet very easily. That is why the electromagnet was invented. An electromagnet is basically a magnet that you can turn on and off using electricity. It’s usually constructed out of a conductive wire wrapped around a permeable metal, and when you hook it up to a power source, the electricity goes through the coils of wire and creates a magnetic field. The advantage of using an electromagnet over a permanent magnet is the fact that an electromagnet is only a magnet if electricity is flowing through it; so, if you want to remove something from the electromagnet, all you have to do is turn it off.

So, what do magnets have to do with electrical motors, you ask? Just about everything, of course! Magnets are what causes the motor to move, utilizing both a permanent magnet and an electromagnet. For now, I’m going to forget about all the other components of the motor and will just be focusing on how these two magnets work with each other (I’ll explain how these factor into the rest of the motor later). The permanent magnet remains in place, and is what causes the electromagnet (the armature) to move. If you pay attention, you’ll notice that the first half-turn is just due to the normal behavior of the magnet; opposite poles being attracted to each other. The goal then is to have the electromagnet’s poles switch, so that the north pole is now facing another north pole and will be repelled from each other, completing the turn. The electrical field in any motor is flipped by the commutator. The diagram below shows how the commutator and the brushes work simultaneously to let the current flow into the electromagnet and flipping the direction that the current is flowing in just at the right moment, so that the motor will turn and the poles switch. The flipping of the magnetic field occurs when the electromagnet moves through a plane that is perpendicular to the magnetic field of the field magnet.

Now for the specific parts of the motor. A simple electrical motor consists of 6 main parts:

1. The Armature, which is the electromagnet. This is made by winding conductive wire around two or more metal poles.

2. The Commutator, the split-ring device that is attached to the electromagnet, allows electricity to flow into the electromagnet, and the device that flips the magnetic field. This is generally made out of a cylinder and two metal plates, with a small spaces in between the plates.

3. The Brushes, which pass the current through the commutator and therefore into electromagnet. These are generally made out of springy metal or carbon fibers.

4. The axel/shaft, which holds the armature and commutator. A simple melt rod will suffice.

5. The Field Magnet, which is the permanent magnet. You can use any powerful permanent magnet in the motor, but it is recommended that you make your own by neatly wrapping wire around two L-brackets, creating another electromagnet.

6. The DC Power Supply. This varies from motor to motor, but for now we’ll be using a battery.

Motors are basically one variation of an electrical circuit; in order for it to work, everything must be set up to allow the electrons to flow in only one direction, just like with magnets. If the electrons are flowing correctly in one direction and everything is set up correctly, then your motor will work just fine.

The motor turns due to a torque created by the magnetic force, as shown in the diagram below. The force is a result of the electromagnet’s magnetic field.

Sources:

http://electronics.howstuffworks.com/motor7.htm

http://science.howstuffworks.com/magnet1.htm

Permanent Magnet

http://science.howstuffworks.com/electromagnet.htm

http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/comtat.html#c1

http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/motdc.html#c1

BridgeBlog Part 3: Static Equilibrium

When an object is in a state of equilibrium, it means that all of the forces acting upon that object are balanced out; the upward forces cancel out the downward forces, and the leftward forces cancel out the downward forces. However, not all of the forces have to be equal to each other, because their only job is to only balance out the object, and the process has less to do with equality than one might think.An object can be considered within a state of equilibrium if the net force acting upon the object equals zero, meaning that there can be no acceleration (because mass can not equal zero). The net force only equals zero if the object in question is either at rest or moving at a constant velocity, as derived from Newton’s First Law of Motion (if an object is at rest, it stays at rest, if an object is in motion, it stays in motion, unless it is acted upon by an unbalanced force).The focus of this blog will be on the state of equilibrium when an object is at rest, otherwise known as “static equilibrium” (static can be defined as unchanging, stationary, or at rest), and how to find it.

A common way of finding the static equilibrium of an object is by hanging said object by two or more strings (in this case, only two are used), and measuring the forces exerted at the angles that are acting upon the object.

When the object stops moving and remains that way, measure the angles and amount of force that each of the two strings are exerting on the object (see diagram below for an example)

If those are your results, you can then either find the vector sum of each force, or the resultant force, which should be equal to zero…

…or you can use trigonometry, as the components of each vector can be compared to see if the vertical forces and the horizontal force are balancing each other out:

However, because it is impossible for your measurements to be perfectly exact, the results may not equal zero. In this particular example, there was an error in measuring the exact lengths of forces A and B:

Fx = 3.1N (to the right) – 3.2n (to the left) = -.1N

Fy = 1.1N (up) + 8.6N (up) -9.8N(down) = -.1N

So, while the answer might not be completely exact, it is still close enough to be considered correct.

Example Problem: The sign below hangs outside the physics classroom, advertising the most important truth to be found inside. The sign is supported by a diagonal cable and a rigid horizontal bar. If the sign has a mass of 50 kg, then determine the tension in the diagonal cable that supports its weight.

To solve, one needs to first remember their 30-60-90 triangle:

So, we know that the hypotenuse is twice the amount of the force in y, and we also know that in this case, the force of gravity is the same as the force in y because the forces are going in the exact same direction:

So, from there, we can find the force of gravity by multiplying the mass by the acceleration of gravity on Earth:

x = mg = (50•9.8) = 490 N Downwards

And because we know that the force exerted by the hypotenuse is twice the force exerted by the force in y, we simply multiply 490 by 2:

F = 2(-490) = 980N

The force of tension on the diagonal rope must be 980N.

Sources:

http://www.physicsclassroom.com/class/vectors/u3l3c.cfm (information and pictures for static equilibrium)

http://www.physics4kids.com/files/motion_laws.html (picture for Newton’s First Law)

BridgeBlog Part 2: My Bridge

Design:

The bridge design that I chose is a modified version of the Smith truss, without as many triangles. Once weight is applied to the center of the bridge, the forces (as shown below by arrows) will spread out evenly throughout the bridge due to interconnecting pieces. Since the triangle is the strongest geometric shape, is not easily deformed, and it has the ability to balance stretching and compressive forces within the structure.

I also included in my design laminated boxed pedestals to support the bridge with vertical strength.

Building My Bridge:

This is my workspace, where I keep everything that I need to build my bridge. 

Within my workspace, I kept two copies of my truss design that were drawn to scale, so I could use them to make sure my wood was within the correct dimensions in order to build my bridge. It was also on top of these papers where I kept my finished wood, taping the joints together so that I could tell which pieces of wood had to be glued to which and so I could see what pieces I had left to construct.

  

The saw that I used came with a special contraption that allowed you to easily cut wood at certain angles (90˚, 45˚, and 22.5˚). It contained angular slits that the saw could fit into, making the angles as exact as possible. Seeing as how my bridge is mostly composed of 45˚ angles, this was very helpful.

     

As for glue, I used fast-drying and secure superglue over waxpaper. I used the waxpaper as a relatively non-stick surface so my wood would not stick to the table I was working on.

 

To make more precise and much smaller cuts, I used exacto-knives with # 11 blades after tracing the line I needed with a pencil and a ruler.

 

Tape had multiple purposes when I was constructing my bridge: Firstly, it was used to hold multiple pieces of wood together when I was sanding it, so similar elements of my bridge were exactly the same (for example, the triangular support pieces or the pedestal legs were all cut and then sanded together, held by tape, which ensured the result would be that they were the same size); secondly, it was used to hold down sandpaper, the saw contraption, and multiple other materials; and finally, it held the finished pieces together by the joints before I actually glued them together, so I could accurately cut, sand, and shape the remaining pieces so they would fit into the model.

 

For sanding, I used 150 and 300 pt. sandpaper; I used 150 pt. for heavier sanding, and 300 pt. for accuracy and touch-ups.

 

This scale was only used to make approximations. I will be getting a more accurate digital scale in the near future.

  

I kept my scrap wood in a bowl, just in case it might come in handy.

 

I sometimes used clips to hold two pieces of wood that were being glued together when I couldn’t do so manually.

 

My extra wood and glue were in close proximity to my workspace just in case I needed it.

 

I used a pencil and ruler whenever I made measurements, and to check the lengths of the elements of my bridge.

 

I used a protractor to check my angle measurements.

 

I used this scrap wood to make sure all of my elements were within the rules of the contest, especially when I was buying the wood.

Though my bridge is unfinished (I still need to build the roadway and two supports that will go on top), so far the construction has been going smoothly. Here is what the almost-finished product (without the roadway or the two additional supports) will look like:

Horizontal- View

Top View

Vertical View

    

BridgeBlog Part 1: The Physics Behind a Bridge and Different Types of Bridges

Simple Physics:

When it comes to building a bridge, the first concept that the builder must grasp is Newton’s Third Law of Motion, stating that every action creates an equal and opposite reaction. For example, if one were to throw a ball at a wall, the ball will exert a force onto the wall. However, if the ball does not go through the wall but bounces back into the thrower’s hand, then the ball was not thrown hard enough to break the wall, and the wall was able to exert an equal and opposite force onto the ball, causing the ball to go in the other direction. If the ball goes through the wall, however, then the wall was not strong enough to create an equal and opposite reaction and collapsed due to the overload of force. It is the balance of these two forces that is key to building a bridge. 

When building a simple beam bridge, one must take into consideration the weight of the roadway and the reaction of the support. As the weight pushes down onto the supports, assuming that the majority of the weight is being exerted within the center of the bridge, the supports must exert an equal and opposite reaction onto the weight so that the bridge will not collapse. In other words, think of the weight of the bridge being a weight (mg), and the supports being the normal force (F_N) that acts against it. These two forces, which in this case are both in the “y” plane (vertically), must equal each other so the bridge does not collapse. When there are cars (ect) traveling on that bridge, however, the supports must exert a force that is much larger than the force of the bridge in order to keep the bridge from collapsing.

For example, say that the overall weight of a bridge is 500N (not including cars, buses, ect.), and the bridge will have four supports. The equation to find the amount of force that each support must exert on the bridge would be found like this:

FN – mg = 0

FB  (Weight of bridge) + 4FS (force acting against weight) = 0

-500N (because this force is going downwards) + 4FS (because there are 4 supports) = 0

4FS = 500

FS = 125 N

This means that each support must exert a force of more than 125 N, so the bridge can hold its own weight and can hold cars, buses, ect. If you want the bridge to be able to hold 600 additional newtons of cars, buses, ect. then the equation would look like this:

-500-600N + 4FS = 0

4FS = 1100

FS = 275 N

This means that each support must exert an additional 150N onto the bridge if it wants to hold an extra 600N of weight.

All four FS’s need to be more than one FB

Of course, this is only a straightforward method for building a simple beam bridge. There are many different types of bridges that can be built, and so many ways to distribute the weight of the bridge so that it does not collapse.

Different Types:

There are four main factors used in describing a bridge:

1. Span

2. Material

Some examples of materials are stone, concrete, and metal

3. Placement of the travel surface in relatio-n to the structure (Trusses)

 In a deck configuration (top), the structure is built underneath the road and is cross-braced on the bottom; in a pony configuration (middle), the road is built between two parallel trusses that are not connected at the top; in a through configuration, the road is built between two parallel trusses that are cross-braced above and below the bridge.

4. Form

The form of the bridge is the most important part of the construction, because the builder must find a way to distribute the weight of the bridge and people on the bridge using a truss or some other method.

Beam/Girder:

A simple beam bridge, such as the one discussed earlier, would most likely be built using metal or reinforced concrete. Girder types are usually constructed using metal dividing the bridge into pieces, and are cross-braced between two beams.

Many modern bridges use the rigid frame type, a design that integrates both a superstructure (a structure built on top of something else) and a substructure (an underlying or supporting structure). More often than not, the legs or the intersection of the legs and the road are one piece divided into sections.

Arch Types:

An arch bridge can be designed using the deck, pony, and through trusses, but must be built using hinges, allowing the structure to respond to various stresses and loads. (A through arch will be used to demonstrate):

The configuration of the arch should also be put into consideration. Some common examples are solid-ribbed, brace-ribbed (or a truss arch), and spandrel-based. A solid-ribbed arch is normally constructed using curved girder sections. A brace-ribbed uses a curved through truss rising above the road. A spandrel-based arch (or open spandrel deck arch) holds the road on top of the arch. An arch bridge normally relies on vertical support to transmit the load, but some metal bridges that are spandrel-based are cantilever bridges, and rely on diagonal bracing for support.

The “tied” or “bowstring” arch is normally used for suspension bridges, and the arch can be either trussed or solid. A tied arch holds its own weight by using the road itself as a tie piece.

The spandrel itself can be either closed or open, depending on the type of bridge and how much reinforcement it needs.

Simple Trusses:

A truss is a structure that is constructed using smaller parts. The simplest trusses are the king post truss and the queen post truss, though the latter is slightly more complicated and adds a horizontal top chord to increase its length (and the center is not as reinforced). As trusses evolved, the triangular shape began to be used more frequently, as the triangle is not easily deformed and its ability to balance stretching and compressive forces within the structure.

Covered Bridge Types (Trusses):

These bridges are typically made out of wood, with an enclosing roof protecting the timbers from damage and decay, therefore extending the life of the bridge. The most common trusses used to achieve this goal are the multiple king post truss, which expands upon the original king post truss shown earlier by adding symmetrical panels, and the Howe truss, which, in its simplest form, seems to be another expansion of the multiple king post truss. The long truss, developed by Stephen H. Long, and the Burr Arch Truss, developed by Theodore Burr, also expanded upon the king post and queen post designs.

The town lattice truss, developed by Ithiel Town, used planks rather than the heavy timbers required to construct the king post and queen post designs, The Haupt truss, developed by Herman Haupt, concentrates the majority of its compressive forces through the end panels and onto the abutments at the end of the bridge. With the development of the Smith truss (designed by Robert Smith), the Partridge truss (designed by Reuben L. Partridge)  and the Childs truss (developed by Horace Childs) were created.

 

Pratt Variations of the Truss:

The Pratt truss, originally created by Thomas and Caleb Pratt, is a frequently-used truss that has many variations. To identify any type of Pratt truss, however, all one needs to do is find a diagonal web members that form a V-shape, and the center section has crossing diagonal members. One variation, created by Charles H. Parker, is a truss that has a top chord that does not remain parallel to the road, creating a lighter structure without losing its strength, allowing for more of the strength to be concentrated in the center and freeing the ends of extra load. The Whipple truss (developed by Squire Whipple), is a stronger version of the Pratt truss, with the diagonal tension spread across two panels rather than just one. It is most commonly build like a trapezoid, though bowstring versions were created as well.

Warren Variations of the Truss:

The Warren truss, developed by James Warren and Willoughby Monzoni, are usually built using many equilateral or isosceles triangles formed by the web members that connect the top of the bridge to the road. The triangles are often further subdivided.

There are many other types of trusses that were used beyond those mentioned here, but they are not as commonplace as those listed. Some examples are the Bollman truss and the Fink truss.

Cantilever Types:

Cantilevers are structural members that projects beyond its support and is only supported at one end, allowing the bridge to achieve greater spans than those of the same superstructure type. Some bridges that appear to be arch types are actually cantilever types, which can be identified by the diagonal braces used in the open spandrel. Pratt and Warren trusses are the most frequently used trusses for this type of bridge. The original cantilever uses a through truss extending above the deck, or above and below the deck.

Suspension Types:

The bridges that are suspension types or their cousin, the cable-stayed bridge, are the longest bridges in the world. The road is supported by suspenders of wire rope, eyebars, or other materials.

 

Sources:

http://ffden-2.phys.uaf.edu/212_spring2011.web.dir/Peter_Aumau/basic-physics.html

http://pghbridges.com/basics.htm (information and pictures)

http://www.mathsinthecity.com/sites/most-stable-shape-triangle

Apple Dictionary

RoboBlog Part 3: Programming Robots (How To)

 

Programming a robot is the most important part of building said robot because without programming, it would just be a heaping but well put together scrap pile of metal, plastic, or whatever it was built with. The way you can go about doing this, however, can vary depending on your materials. You can keep it fairly simple by only using a few sensors that can detect light, sound, ex cetera, or you can attach a whole ton of sensors that will make your robot more advanced. 

You first should chose the language to program your robot in. No, not English, Japanese, or French: we’re talking about programming languages. A few examples would be Basic, one of the most common-place programmers and is used for educational robots, Java, a modern language with a ton of safety features but is a disadvantage when it comes to low-level control, and Python, one of the more popular programming languages that is simple, efficient, and altogether one of the better ones out there. If you’ve chosen a more popular programming language, there are probably a lot of other sources and guides you can use to help you understand them.

Next, get started. The first program you will probably write is called, “Hello World”, one of the most fundamental programs that can be made into a computer and its intention is to print a line of words on the computer monitor or whatever screen you happen to be using. In the case of a microcontroller, another really basic program that has more to do with the robot rather than the computer, is toggling an IO pin. Connect an LED to one of these pins, and then set the pin to ON and OFF, causing the LED to blink. This function will allow a lot of complex programs, including lighting up multi-segment LEDs, displaying words and numbers, and operating relays. 

 

A microcontroller

 

Then follow these steps:

1. Ensure you have all components needed to program the microcontroller. Keep in mind that most microcontrollers will need to be connected to a computer via a USB drive.

2. Connect the microcontroller to the computer and verify which COM port it is connected to.

3. Check product’s user guide for a sample code and communication method or protocol.

4. Start programming your robot!

Source: http://www.robotshop.com/blog/en/how-to-make-a-robot-lesson-10-programming-your-robot-2-3627  

RoboBlog Part 2: Our Robot (The Puppy)

Our robot, known as “The Puppy”, is basically a robotic dog. Using color sensors and building a bone using multiple colors, you can program your puppy to do what normal dogs do in their everyday lives. For example, whenever it senses the color red, it will start eating the bone. You can also program it to bark, whine, growl, and sleep. It’s everything you want in a puppy without actually owning one!

Link to How to Build: http://robotsquare.com/wp-content/uploads/2013/10/45544_puppy.pdf

Link to see it in action: http://www.youtube.com/watch?v=HJ3XLFsd4zI

RoboBlog Part 1: Robotics (The History Of)

Robotics is a section of technology that focuses on the design, programming, usage, and building of robots and computer systems that have to do with robots. However, even though our generation seems to have more of an advantage of creating these mechanical beings, it has been discussed and even attempted throughout history, even dating back to Aristotle. Granted, Aristotle’s view of science and physics is not the most reliable, but he did say this: “If every tool, when ordered, or even of its own accord, could do the work that befits it… then there would be no need either of apprentices for the master workers or of slaves for the lords,” and that ever so happens to be the goal of all robots.

The study, or in this case the discussion of robotics began with the concept described by Aristotle in 320 BCE. Around 1800 years later in 1495, the world-renowned Leonardo Da Vinci began to sketch the concept of humanoid robots. Another 200 years later, life-sized automatons were created, becoming the first technical “robots”. Then, when the 20th century comes along, the advancements in robotics sky-rocket.

In 1913, Henry Ford created the world’s first conveyor belt-based assembly line in his factory, reducing the time to create a Model T to a mere 93 minutes. In 1920, Karel Capek dubs machines that resemble humans “robots”, in his play, which depicts a society where robots have taken over the world. In 1932, the first actual robot was created in Japan, called the “Lilliput”- a wind-up toy that could walk. in 1937, Alan Turing began the computer revolution with his paper “On Computable Numbers”. Then the ideas just kept coming, influencing many science fiction movies such as The Terminator, Star Wars, and 2001: A Space Odyssey. The advancement of robotics was also responsible for landing Neil Armstrong on the moon, LEGO-based educational projects such as what we did in class, robotic arms, satellites, robotics being used in medicine, and finally humanoid and dog-like robots.  

Sources:

Apple Dictionary

http://www.sciencekids.co.nz/sciencefacts/technology/historyofrobotics.html 

Catapults: Different Types and How They Work

Catapults all have one purpose: to hurl objects, or projectiles, into the air. These projectiles can range from the harmless ping-pong balls launched in a classroom to huge stones meant to crush enemies. Though most people imagine the catapult to be a contraption that looks like this, ” “, there are actually three types of catapults.

1. The catapult is the winched-down bucket that people generally think of when the word “catapult” is said. These catapults were large weapons invented in the Middle Ages, normally on wheels, with a basket attached to a long wooden arm and a power source for hurling objects into the air. The power source normally comes from the gears, which can apply to all the catapults listed (more on that later)

Picture of catapult: 

2. The ballista is a large crossbow, and it’s “ancestor” was actually the first version of the catapult. It’s “ancestor”, the Gastraphete, was invented in 400 BCE in Greece. The Greeks were apparently so impressed by the mass destruction of the Gastraphete that they invented a bigger version, which is known as the ballista.

Picture of Ballista: 

3. The trebuchet is a weighted beam that swings a sling carrying the projectile. It is the most recent creation of the catapult family. The trebuchet, unlike the catapult or the ballista, uses the principle of a counterbalancing weight. In other words a heavy weight is fastened to one end of a large beam and a pouch for the projectile on the other end. The beam is on a solid stand or a supporting frame, and is able to launch the projectile in the pouch rather far.

Picture of trebuchet: 

Gears are very important because they create winches. Winches allow people to put a great amount of energy into a catapult over time, and when all the energy is released, the projectile is launched.

Those are the three main examples of a catapult.

Sources:

http://science.howstuffworks.com/transport/engines-equipment/question127.htm

http://www.midrealm.org/mkyouth/links/catapults.htm