Last Days

Since its the end of the year, I thought I would give you a chance to reflect on everything that's happened in the class. Think about everything we've gone over, both the third and fourth nine weeks. What things did you like? What things did you not like? What gave you the most problems? If you could change one thing, what would you have done? Try to be honest and don't forget to explain your statements!

Back to AutoCAD

This last week you have been using the Autodesk Inventor CAD program to design your Mag Lev cars. It is very apparent that many of you have forgotten how to do some of the things we did when we were doing the Race car designs. While you remember the basics for drawing, setting the measurements, and extruding, most of you have forgotten what comes after you create the basic form. That is, you have forgotten how to change a pre-made form into what you want. You have to create a new sketch on one face, draw the shape to remove, then use the extrude tool to cut it away.
After you have the basic block for the foam body of your Mag Lev car you must shape it. There are four things to consider:

1. There must be a place to attach the electric motor. Basically a notch that is an inch long and three quarters of an inch wide.
2. The propeller has a radius of just under two and a half inches. You must have clearance for the propeller to move freely. This is only a problem if you put the motor in the middle of your car.
3. You must be able to place the four magnets on the bottom of your car. Since the track is already made there is no wiggle room for how far apart on the sides you must go.
4. Your car must be shaped so that air can flow over it smoothly. To help you understand how the car would move we used the idea of a swampboat, but they are not shaped to move through the air, but on top of water. Think of a racing swampboat. If you shape you Mag Lev car like a racer with a swamp boat engine you've got the right idea.

What problems have you had in designing your Mag Lev car?

Raceday! Raceday!

Monday is the big race!! We will be running a double elimination bracket tournament to decide who is the class champion. Then we will run the 6th hour champion, the 7th hour champion, and the Fall semester champion in a three-way round robin tournament to determine the winner of the year!
Monday is also the day we will be grading your racers. Your race cars will be judged in three categories; design, speed, and appearance, and be worth 200 points. In design you get points for being nine inches long (I'll spot you the 10th inch), having low weight, aerodynamics (how well the air flows around the car), and how much effort went into changing the wood block's appearance. In speed, we will take the car's speed and sort them into groups of four. The fastest four get 100% of the points, 2nd fastest 90%, and so on. In Appearance, I will judge things like paint job, how 'cool' the cars shape is, etc.
If your car is not here on Monday you will lose 25% of your grade and automatically be placed in the loser's bracket. So make sure your car is here. Excuses will not be accepted.

Sanding, Sanding, Sanding

Hopefully, you have finished cutting out the rough shape for your car and filing the edges smooth. At least, that is the plan on the schedule. In reality I know that some of you are still working on this. Now comes the time that can be the most frustrating; sanding.
Sanding does two things for the car. First is improves the air flow around the car by removing bumps and dents. This allows the car to move through the air with less friction or drag, i.e. faster. Second is it preps the car for painting, because all those nicks, dings, and bumps really show up when you paint your car. The better you sand your car the better your car will look.
Since everyone will have the same "engine" powering their car, in our case compressed air. There are only a few things you can do to make it faster: lighten the car or reduce the friction/drag of the car. How is your car design going to help your car win the race?

Air Powered Dragster

This week we started building the dragster that you designed back before spring break. The idea is to take the concept (idea) of your car from the computer design and try to create it in real life.
This is how the engineering process works.
In creating your car you are going to move through a series of steps:

1. Drawing the design onto the wood block
2. Drilling the axle holes and any holes you need so you can remove wood from the center of your car.
3. Using the scroll saw to rough out the design of your car.
4. Using the files to round off all the edges and smooth out the car design.
5. Smoothing out all the surfaces of the car with sandpaper (this takes a lot of work)
6. Painting the car (I'm still not sure if I will have you actually do this step)
7. Assembly of the wheels and axles
8. Testing the car for speed and ease of movement.

Then we will actually race the car, which we will not about more later.

How is your car design coming?

Closing out Goldberg

After today your Goldberg project should be finished. You should have a list of all the materials you used and how many days you used each of the tools. This should be all filled out in a table in your engineering notebook.
Your machine should be completed and set up so that when you do a starting action it triggers the next machine and so on until all six of the simple machines have been used. You should also be able to point out each of the six types of simple machines and tell me what it does for the Goldberg machine.
Monday you will show how your machine works and fill out a form that tells me what each person did to build the machine and how you worked as a group.
How did your project go?

The Project

You've had a good taste of your Goldberg project now, and I know some of you are having problems. Your problems will basically boil down to one of three things.
First, you are having problems constructing your machine because you can't figure out how to put things together. This is why you were supposed to draw out a sketch in the planning stage (which many of you did not do.) In order to do this you had to think about what each type of simple machine did and how you would connect them together in a chain. This is much harder to do on the fly when you are building than when you are sketching out a plan. The good news is that even if you had a great plan you would still run into places where you had difficulties. That is normal.
Second, you are having problems with your group. This also is normal. Working together in a productive way is not always easy. It is a very important skill to learn. It is also hard to do when some members of the group do not have the maturity needed to stay on task and they wander around talking to friends. These people are the ones who are always getting fired when they are adults, but they never understand why.
Third, we have the glue gun snag. Because we do not have enough that every group can have their own it can cause problems. There are three ways to work on this problem; 1) share the glue guns, which many of you have been doing, but it does slow things down. 2) get more glue guns, which I am working on. 3) plan out what you are doing so that one day you don't use the gun and get everything else cut, shaped, and ready, then the next day you ask for a glue gun early and take care of everything.
What problems have you been running into? What have you been doing to solve them?