Macguire's+Journal

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Macguire's Journal

Geoffrey, Julien, and I will be working together to recreate Da Vinci's Crossbow.

=February 19, 2009= I learned that when gears turn, the larger gear will turn more slowly, but will turn with more force. I also learned that there are way more types of gears than I thought.

=February 26, 2009= I think this is the order of the levers.

= 1st class = -The fulcrum is at the bottom, the force is at the top, pushing up, and the load is in the middle.

= 2nd class = -Seesaw. The fulcrum is in the middle, the force is at one side, pushing down, and the load is at the other side.



= 3rd class = -The fulcrum is at the bottom, the force is in the middle, pushing up, and the load is at the end.



We were experimenting with the seesaw lever method. Audrey was sitting on one end of the seesaw, and we were pushing on the other end to lift her up. The seesaw part of the lever was about 6 feet long. Then, Mr. Kennedy got a longer one. I thought it would be harder to lift Audrey up if it was longer, because it would bend more, and somehow, not have as much force as the shorter one, even though we were pushing with the same effort. Then we tried it, and I could lift her up all the way with 1 finger. We pushed at the very end first, and it was really easy. But then we moved up, to where the end of the shorter piece would have been. It was much harder. A few people even struggled to push it down. Mr. Truss explained a very interesting thing about a series of mechanical objects. Take a pulley for example. He explained that if you have a pulley, and you have something on the other side of it, and you pull the rope on your side 1 metre down, you would only be raising the thing on the other side 1/2 of a meter, because the rope had 2 sides. One was on one side of the pulley, the other was on the other side. So by pulling it 1 metre down, you would make it 1/2 a metre shorter on each side, so the thing would only go up 1/2 a metre. Another thing that he showed us made me get an idea. Mr. Truss got one of the students on his back, and the tried to get onto a table. Without his hands. He couldn't do it. But then he got a piece of wood and made a ramp going up to the table. He walked up it effortlessly.He explained that it was harder to go just onto the table, but, if he made a ramp, it would be easier. But he would have to travel more distance to use the ramp, but just one step with just going straight on. It's like walking and running. Running takes more power, but is faster, and walking is easier, but slower. That brings me to wonder; which is better? Walking or running?

=March 5, 2009=

Today, I've learned that the order that I thought the levers were in was wrong. This is the way they should be.

= 1st class =



= 2nd class =

= 3rd class =



=March 31, 2009=


 * 1. You will be exploring a Da Vinci inspired topic, of your choice, and going into great detail. What subject or subjects are you interested in?**


 * The Da Vinci Crossbow.**


 * 2. What interests you about your subject? Why is it something you want to know more about?**


 * How it would work, all the parts involved. I think it would be a challenge to try and figure out how to piece together a bunch of things to make them fire a pencil or something.**


 * 3. Would you rather work individually or in a group? And what is the largest group that you would be interested in working in?**


 * I would rather work in a group, because then we would have more ideas, more ways of doing things. I don't care how many people, as long as most of them participate, but at least more than just me.**


 * 4. Look at the images on the In-Class page for March 12th. For each of the levels/skills on Blooms Taxonomy that we discussed, use the key words in the image to tell us some of the things that you might do in your wiki assignment, in order to demonstrate each of the skills.**

Remember/Understand: research discover locate

Apply: sketch construct

Analyze: compare chart

Evaluate: recommend decide conclusion

Create: hypothesize

=April 16, 2009=

My group, Julien, Geoffrey, and I, are going to create a crossbow made of wood and various other materials. We are going to quality test all the items that we use, to see if they are up to our standards. We will make the main frame of the bow first, in a kind of cross shape. We will then create the firing mechanism. Julien is going to come over Friday, April 17 to make the frame. We will have various meetings along the course of the project timeline, creating the bow.

=June 11, 2009=

Our group, Julien, Geoffrey and I, have finished the crossbow, except for the firing part.

What worked
1) We took a piece of wood. It created the stock. 2) We took 3 pieces of Plexiglas™, tied them together, and that created the limb. 3) Geoffrey had a great idea. He made 2 metal brackets at 90° angles to attach the limb to the stock.

What didn't work
1) We needed a way to attach the limb to the stock. We couldn't just screw the limb into the stock, because we would be screwing into the grain of the wood, which would weaken the stock alot. We needed a way to attach the limb to the stock without weakening the crossbow. Then Geoffrey had a great idea. He got a piece of metal, an cut 2 strips out, then bent them 90°. He attached one side of the bracket to the stock and the other side to the limb. Success! I know this is in the "What didn't work" section, but it was a problem. 2) While we were drilling a hole in the Plexiglas™ pieces, Hayden decided to hijack our project control room and smashed the drill bit into the Plexiglas™, and it got decimated.

What we would do differently
1)Nothing

What I've learned from doing this project
1) Higher level thinking skills 2) How to understand different perspectives from other people