Monday, March 23, 2009

Tractor Pull - Experience





"Get in Gear" and "Gears and Speed" - Experience (Comment)

I've only just completed the two activities ("get in gear" and "gears and speed) recently; furthermore, it proved to be significant in my understanding of gears and can be useful in future projects/activities.

"Get in Gear"
- the activity introduces gear ratio. Gear ratio is the ratio of the driven gear to the driving gear; this is significant to my understanding as it plays a main role in the robot's speed and strength (depending on its setting or ratio).
- probable gear ratios and benefits:
1:5 = small driven gear and big driving gear
5:1 = big driven gear and small driving gear
1;1 = both driven and driving gear have the same amount of teeth = motor's speed

"Gears and Speed"
- the activity focuses on calculating speed in relation with gear ratio of a robot. It introduces two hypotheses that presumably is able to calculate the correct speed: however, only one of them is correct, so i had to experiment both hypothesis (compare with average speed)in order to find out which one is correct. In the end i found out that hypothesis B was correct.
- Hypothesis B ( speed 1 * gear ratio 1 = speed 2 * gear ratio 2) is approximately the average speed of the the three trials.

Formulas:
Gear Ratio = driven gear/driving gear
Hypothesis A (incorrect) = (speed1/gear ratio1)=(speed2/gear ratio2)
Hypothesis B = (speed1*gear ratio1)=(speed2*gear ratio2)

GoodgleDocLink:

https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhg5FPXdWG7pdhIV5WrYSdx7blYQofFXiTwE9X0l89OgWYzeILGbwHDrjLqzTyioUUKYOgeafsXCBMqaxLqdX_Do6ChCJmR0DCwGnvJU1AUEE8InYrRtlbf-8pw4GsW64gtlJzIbQhe_E0/s1600-h/google-doc_gear+ratio.jpg

Monday, March 16, 2009

Chapter 2 - Playing With Gears

This chapter consisted of several concepts: angular velocity, force, torque, friction and gear ratios. The chapter also introduced gears and other parts that are able to maximize a robot’s capability – making robots able to perform specific tasks that of which needs certain parts in order to be accomplished. I say the highlight of this chapter is “torque” as it is what makes robots capable of performing task that involve force and weight; additionally, there are ways to control/adjust torque and at the same time, avoid any disasters – clutch gear, belts and pulleys are some of the main objects in the kit that is able to prevent any harm that might come to your robot. In addition to the highlight, gear ratio is another important aspect when building a robot. Gear ratios can mean a lot to a project depending on what the given task is and needs - e.g. speed, strength, etc. From what I know, there are simple aspects of gear ratio that give away its primary purpose - e.g. A setting with a large driving gear and a small driven gear maximizes a robot's speed (The reason why is pretty simple once you think it out. With a smaller driven gear the axle is able to spin faster due to the gear's smaller circumference.) , while a setting with a small driving gear and a large driven gear maximizes its strength capability.

"Common Gear Sense"

*Gear Ratio = driven/driving

E.g.

5:1 (larger driven gear than driving gear) = strength

1:5 (smaller driven than driving gear) = speed

1:1 (same size) = -----

In my opinion, this chapter is interesting as it will help us in the near future with our projects. “Not boring, Just complex”

Tuesday, March 3, 2009

Chapter 5 - "Record and Play Back"

The chapter provided information on the "record and play back" block. This chapter of which I chose proved to be somewhat of an extra as it teaches us how to simply record and play back certain parts of a program or a program itself. This feature can be pretty nifty as it can help us store sequences that could be significant to a project's progress. The configuration is simple enough, in order to record simply select the part of the program that you desire to keep as a reference - the file will be stored into the NXT-G once uploaded.

Even though nothing else can be done by the block, it still is a nice feature that would come in use during one's presentation.

Chapter 4 - "Get Movin"

The chapter talks about the "move" block and its configuration. The move block is somewhat superior (in my opinion) to the motor block - Why? Well first off, the move block has more options than the ordinary motor; programmers are able to operate two motors at a time, also get to configure duration and turn. By having more options in just one block makes programming much more simple; however, making accurate turns is more complex when using move blocks - that's where the motor blocks come in handy. Although the motor block controls only one part and needs the help of other icons to stop or measure duration, its much more simple to calculate an accurate turn.

Both are very useful, but I prefer to use the move block as it has more advantages than the motor block.