Monday, November 28, 2005

Galileo Group

The Galileo group chose their name after doing research on the NASA site--Great choice!
They also produced a great bulletin board describing the NASA Galileo mission. I learned so much about the project. I was very suprised the group went so in-depth to find the group name. Well done.

Picture Credit:

Tuesday, November 22, 2005

Complex Programs: Using Segments

I like to borrow techniques that other people come up with to solve problems.

So I have applied the Math Problem Solving Technique of "Make it Simpler" to help me make a large overwhelming problem a series of smaller, more managable segments.

Yesterday in class, we discussed how this idea works. Please post a comment describing the mini-steps you might use to get your robot to the submarine and back to the base.

Wednesday, November 09, 2005

Rotation Sensor Angle Sensor

Here is a picture of one of the Lego sensors known as an Angle Sensor or a Rotation Sensor. Notice the hole in it. That's where an axle fits.

Here is how it works. The sensor senses the rotating axle. It counts in little steps a sixteenth at a time. When the sensor port displays 16 it is telling you that the axle rotated one full revolution.

So to make the sensor useful to all of us future engineers, we can measure the distance we want to go by using the "View" feature on the RCX. Then in Robolab, we enter the numerical value we took from View and enter that value into numerical input on the sensor icon in the code. Small adjustments are made after some trial and error for that mission. This becomes a very acurate method to measure distance.

The Angle Sensor gets that name versus Rotation Sensor from this: Since the sensor counts in small bits at time and those bits are equal and there are sixteen of them, people who know these characteristics divide the 360 degrees of rotation by the sixteen bits and now can measure angles. Each increment of that division problem yields 22.5 degrees- Very helpful when using an Angle Sensor on a motor for an arm. Two counts is 45 degrees. Four makes 90 degrees and so on.

Does this give you any ideas?- if so post a comment. Use rules of regular English like Capital Letters! These posts are getting sloppy. This is a forum for intellectual exchange between students and teachers. It is not a place for AOL lingo. I want your comments- not slang.

Keep in mind this is the WorldWideWeb- anyone, anywhere may read this. Your potential audience is anyone in the world with internet connectivity. You are known only by what and how you write. If you write nonsense- well, there you go. BUT! So many of you write such execellent comments. We get very good feedback about your participation. That makes me so proud of all of you!

Tuesday, November 08, 2005

More Training at ITHS Election Day

More training! Lucky me. The Region 4, NYCBOE guys Norm and Steve are at it again.
You see me and Norm working out an angle-sensor problem on my 'Bot. Their training techniques are "hands-on" which means they are having the teachers try to score points on an Ocean Odyssey board just like you.

I am trying to get the 'Bot to move the Reef to shallow water and then move up the Barge to get the Research Submarine. What challenge are you working on. What's next?

Thursday, November 03, 2005

Gears, Gear Trains 11-3-05

Gears can be confusing! Today in class we had a great experience discussing,predicting, observing and making conclusions about the simplest of gear ideas.

We found out that when a 40 tooth gear turns for one revolution that the 8 tooth gear will turn 5 times. We then used that idea of gear ratio to discuss bicycle gears in relation to speed, effort, and power. We'll discuss some other concepts like torque in the near future.

What a day! I think several students were not very clear about how the ratios work. Now I think we made progress. We will do more demonstrations with gears and wheel size. The demonstration with the two robots with identical gears going different speeds due to different wheel size was an eye-opener too!

Any thoughts about todays demonstrations or ideas for further discussion?
How about just telling me one simple thing you learned today?
I would like a comment from every student.


Lego Constructopedia Explains Gears!


This site has great moving graphics to help you understand gears and pulleys!