Motor Project Part 1

     For this post i will talk about some of the materials needed for this project as well as how to build it. This project took about a day and a half to build and also to fix any problems (which their were a ton of) and also telling other people and helping them with theirs. First off, this project needs time so you can't do this the night before and it is extremely labor intensive so make sure you have all of your sanity and strength before starting because it will drain your batteries (pun not intentional).

     For the materials you will need

1. 2 L-joints or 1metal strap (steel or iron also make sure their thick)
2. A 6-volt battery
3. 24 gauge wire (100 to 200 feet should be enough)
4. 14 gauge single strand lamp wire (around 100 feet)
5. Pieces of scrap metal (I used copper)
6. Multi-strand wire (lamp or speaker not a lot is needed)
7. Copper foil (Teacher supplied this to me)
8. Cork (Optional)
9. Spool (Optional)
10. 2 16-penny nails
11. Electrical Tape
12. Silicon Tape (Optional)
13. Wood Board
14. Switch (Optional)
15. Darning Needle (9 to 10 inches min.)
16. Screws (size depends on width of board)

     Of course you are going to need some tools like scissors, screwdrivers, and a ruler but thats all common sense

Here is some of the materials needed not all

     So now that you have collected the materials you need to assemble them all into a working motor, i believed that this would be the easier part of the project (famous last words). So any way i will give you a semi-detailed way on how to build each part. We have 4parts the armature, commutator, base magnet, and brushes.

     First, i will be discussing how to build the armature so the materials your going to need are the nails, electrical tape, needle, and 24 gauge wire. To start off first put the 2 nails right next to each other so that the end of one is next to the head of one as shown in picture below. Then hold them straight and wrap them in electrical tape maybe 2 times. Then find the middle of the taped nails and stick the needle through it and make sure that the nails can't turn freely on the needle.

Semi-wrapped armature

     Then take out the 24 gauge wire and measure out 6 inches and start wrapping leaving the 6 inches for connections make sure you start right next to the needle and start wrapping (neatly) all the way to the end and then wrap back to the needle overlapping the first layer of wire. Do this one more time until you have 4 layers of wire and are next to the needle and then slowly cross per the needle and make sure to not change the direction the wire is going or it won't work. Then repeat the wrapping process until you have equal layers on both sides and then like the other side cut off the wire leaving 6 inches for connections.

     Secondly, we will make the commutator which is made out of the cork (but you could use tape), tape, and copper foil. To make the commutator put a hole through the entirety of the cork in the middle, (Side note: For the commutator you can also wrap electrical tape around the needle to make a cylinder with a diameter of ½ inch but anything can be used). Then cut the copper foil to fit the length of the cork and have a length of ¾ inches.

A finished commutator with the armature attached to it

The commutator should then be put on the needle and you should take the two copper strips and place them on the cork bending them so they fit as well as making them opposite on the cork piece. Take a strip of electrical tape that is really thin and put it on the far side of the cork holding down the 2 pieces of copper. Then take the excess wires and put one of them on one of the copper pieces and the other on the copper piece on the opposite side of the cork. Then take a wider piece of tape and tape the 2 pieces of copper and the wires to the cork, this completes the commutator.

    Third of all is the base magnet you will need the 2 L-straps, 14 gauge wire, and electrical tape. To make this you will need to put the steel L-straps together to form a U shape or take a steel metal strap and form a U shape. The U shape should have a base of about 3 or 4 inches and the sides should be 4 or 5 inches. Then when your done putting them together should then wrap the 14 gauge wire very neatly around 200 times or how many times it allows for. Then wrap it al I electrical tape and take another piece of metal and screw the base magnet to the board.
 
     Lastly you need to build the brushes and make the wire connections, take some speaker or lamp wire (multi-strand) and then solder or tape them to pieces of copper and place them next to the commutator. Then take one brush wire and attach it to the base magnet wire and take the other one and attach it straight to the battery (negative) magnet wire on the other end that plugs into our switch and the switch will go to the battery (positive). This should be all you need to know about building a DC motor

Electric Motors

   Electric motors are everywhere but most recently electric motors have been transitioning into the automotive world with battery powered cars and cars that use less fuel than a normal composition engine but how does an electric motor actually work? An electric motor uses electric energy from a battery to make mechanical energy which makes the motor move. Their are two ties of electric motor an AC (alternating current) and a DC (direct current) the difference is that the DC motor ( the one we built for the project)  has a commutator and a set of brushes while an AC motor has no brushes or commutator and goes faster as well as has a better life expectancy. 

An AC Motor

    

A DC Motor

I am going to be focusing on how a DC motor works but an AC motor works around the same way. First two wires are set up that connect to the electrical source (battery) when it is turned on a current is sent through one wire into a brush which then transmits the current to the commutator ( a cylinder on the shaft that has two metal metal strips on it at opposite points). The brush touches on of the metal strips lets call them them the commutator strips A and B. Commutator strip A is also connected too the armature which when current flows through it creates and electromagnet and then back out onto the opposite side of the commutator and into commutator strip B.  The other piece of wire connected to the battery goes through a base magnet directly under the armature and is then connected to a brush which is  connected to commutator strip B. Finally when the battery is turned on the brushes transfer the current into the commutator and the armature powering it as well as the base magnet. This causes the base magnet and the electromagnet (armature) to interact with each other forming a magnetic field that pushes the armature away from the left and draws it toward the right causing rotation. When the armature rotates so does the commutator and when it rotates around 90 degrees that brushes lose contact with the commutator strips but the armature still moves because of momentum. when the commutator turns around 180 degrees the commutator strips A  and B are facing the opposite brushes which cause the armature to now create a different electric field where the armature is pushed away from the right and drawn toward the left. Their is a another break in the commutator strips and then the cycle repeats itself causing a full rotation over and over again.

Static Equilibrium

Equilibrium is when forces acting on an object are equal so their net force equals zero, by this I mean that opposite forces acting on an object are equal. Although equilibrium has a net force of 0 and acceleration of 0 but it doesn't mean that they are not moving an object at equilibrium is either at rest and staying at rest, or in motion and continuing in motion with the same speed and direction.

Static means unmoving or the act of being stationary. So that means that static equilibrium is when an objects net value is 0  and they don't move and stay stationary.

This models a baby on a board suspended by two adults like how a
 beam bridge suspends a car/truck .

My Bridge

For my bridge I have decided to either make a truss bridge or an arch bridge for my project already i have made a few bridge bases and have already built two bridges to test 

I have decided t use these truss bridge designs because some are fairly easy to make and all will supply a decent amount of support so i can achieve the goal. After researching discovered the bridges that were able to hold a significant amount of weight were truss bridges that had curves in them or arc bridges with triangles and truss bridges that had rigid squares and triangles that

The types of truss bridges I am testing are:

The Parker Truss

Pratt Truss

Brown Truss

I am thinking of also testing this type of bridge it is a mix of a truss and arc bridge.

Bowtring Truss (Arc)

Bridges

A bridge is a structure that connect two points of a road, rail, or track, it suspends the roads from two sides of land usually over a body of water. Bridges are a commonplace item to see while driving so people don't realize how complex building a bridge really is. Architects and engineers have to incorporate how forces like tension (the force of pulling apart two points of an object), torsion ( the force of twisting two points of an object oppositely), compression( the force of pushing together two points of an object), and shear effect (the force of pulling one point of an object upwards and one point downwards) effect their bridge to make sure it doesn't buckle, curve, or snap.

The forces of Tension, Compression, Shear, and Torsion on a block of wood.

A box girder bridge a larger form of a beam bridge

The first bridge is a beam bridges the simplest type of bridges and can be found in a variety of sizes like a small wood bridge to cross over a stream or a large one that can stretch over a river, large beam bridges have pillars that hold up segments of the bridge they are called box girder bridges. The beam bridge is the most common bridge used today because it is simple and doesn't need that much resources and is thought to be the first type of bridge ever made. A single beam spanning any distance has compression and tension acting on it so if enough weight is added to a length of a beam bridge it starts to bend because the force of compression on top of that segment and the force of tension on the bottom of it increases and if the forces get too great the bridge will buckle and snap

  Cartoon shows compression acting at the top of bridge and tension acting on the bottom

A Deck and Through Truss Bridge

The second type of bridge is a truss bridge, which is a bridge that has a structure that forms triangles which is called a truss. This structure can go above (through) or below (deck) the roadway, and the truss allows the bridge to become more rigid and prevent compression and tension. The truss is able to make a more rigid bridge because the triangles allow forces like compression and tension to spread over a larger area and not just on one beam like how a snowshoe spreads your weight over a larger area so you don't sink in the snow. Truss bridges are reliable and use up minimal resources which makes them one of the most common forms of bridges and one of the oldest.

A tied arch bridge (above) and can be held up by wires

The third type of bridge is an arch bridge like the truss bridge it helps spread out the weight so it doesn't buckle or snap and the arch can be above (tied arch) or below the roadway.  A tied arch bridge though does not 

An arch bridge that is connected over a large gap

spread the forces out instead the bridge is restrained by tension. A regular arch bridge has abutments, which is the arched structure like the trusses of a truss bridge and they transfer the weight. Like beam bridges it has repeated arches creating pillars.

A Cable Stayed Bridge

A Suspension Bridge

The forth and final bridge is the suspension and cable stayed bridge which instead of spreading the forces of the bridge. Suspension bridges are suspended from cables and towers the cables hang from towers that are attached to caissons or cofferdams. The caissons or cofferdams are implanted deep into the floor of a lake or river. A cable stayed bridge like suspension bridges, are held up by cables. However, in a cable-stayed bridge, less cable is required and the towers holding the cables are proportionately higher.