Monday, December 6, 2010
Making Of BeetleBot – LMB-2000 Team member: Lee Kien Thiam (10WTD00531) Foong Ghin Seong (10WTD06325) Chong Jia Ying (10WTD04145) Name of the beetle bot: LMB-2000 (Land Mine Boulder 2000) Materials: Two 3V motors, two SPDT switches, four 1.5V batteries, two 2-battery holder, three strip board (?x?), nine Yellow color LED, one multi-color blinking LED, 1meter wire of each black and red, two pairs of wheels, one thin zinc plate, one 50mm clip, plastic package from Nvidia GT-9600 XFX computer graphic card. Apparatus: Soldering iron, soldering lead, hot glue gun, hot glue, pliers. About The Beetle Bot The beetle bot from our group is given a name LMB-2000. It is fully automated-requires no human interfere on steering the bot. There are two SPDT switches that mounted on the front of the bot. When one of the switches is pressed, eg. left side, the right side of the motor will run in opposite direction, where the left side motor will still continue turning in the same direction, causing the bot to turn right. Same goes to the other switches. This feature had given an advantages that it will steer itself even it bupm into an obstacle in front of the bot. The meaning of the name Land Mine Boulders which the idea of the name comes from the concept for future use which is used to detonating the land mine that buried underground. The beetlebot we presented currently is the improvised version from our very first prototype which is called LMB-1000. The design of having a shovel-like bumper installed in front of the vehicle is also a contribution to the name given to the beetlebot. Therefore, in normal condition, this vehicle can also worked as a snow boulders that can remove snow on the path. On top of the bot has also added 10 LEDs that will show the direction of the bot placed inT-shape arrangement. The LEDs are parallel with the motors-they will light up when there is current flow across the motor at the same time. When we start building our beetlebot, we got ourselves the blueprint of the circuit inside the bot and did some minor adjustment to the circuit to it so that it will fit our design’s requirement. After we gather our ideas, the final design of our beetle bot has born. One of our team member is sent as a representative to gather all the required ingredients and we started build our beetlebot on October 16. The basic structure of the first bot, our prototype bot named LMB-1000 was finished at 17 October. However, it contains some flaws. First, the turning force and the power of the motors aren’t equal. This causes one of the motor are turning ahead of another, and the torque of the motor are also different. Consequently our bot spins itself on the starting line. Secondly, LMB-1000 has some wiring problem. When one of the switches is pressed, one wheel will turn backward and the other will turn forward even though we didn’t put the battery for accelerating. This will causes one of the motor to be overpowered and the other left underpowered. And third, the center gravity of the car falls at the front part. This causes the motor that was placed at behind to have less pressure and it easily slipped and the wheels are spinning on the air. Thus, the beetlebot will not moving forward if the ground are even slightly uneven. Forth, the wiring systems of the beetlebot are messy and easily short circuit. This causes LMB-1000 to be very unstable once it hits something. The wire easily crossed and the messy wire are also tripping the beetle bot from moving forward. All of these failures had leaded us back to the drawing board for further improvement. After some more discussion and exchange information between other teams, the plan for improved version of the LMB-1000 has been produced. The plan was set on October 18 and all the required material at the second day. And then the construction was conducted on 20 October, and was finalized on October 31. In the improved plan, we added 10 LEDs to beautify the plain-looking beetle bot and also, it has a practical function – to indicate the direction of the beetle bot heading. We have also improvised the switches that mount on the front of the bot from a long antenna to spring loaded bumper to maximize the area of contact but at the same time to reduce some of the force during impact from damaging the beetle bot. The new LMB-2000 has a chassis built form 2 strip board of dimension ?x?. Instead of using 2 batteries, we used 4 1.5V batteries to power the beetle bot. Because of this, the extra power supplied to the system can used to power the LEDs since the minimum voltage requirement of a LED used by us is 3V. The LEDs are soldered to another piece of strip board of dimension ?x?. Then it’s wired to the main body with all the required connection. The casing of the beetle box is made by the plastic package from Nvidia GT-9600 XFX computer graphic card. Thanks to our team member Ghin Seong, the cover was made to fit perfectly for the beetle bot. It’s transparent and hard, this enables the light of the LEDs to be visible and also protected the circuit from damaging by object that falls on it and rain falls. Below are some snapshot taken after we finish built our beetle bot LMB-2000. In this assignment, we’ve learnt to be patient and determination, we didn’t give up easily in this assignment and this leads to the success of building our very own beetle bot. We also learn some of the basic principle of constructing a beetle bot. We felt very disappointed when the result didn’t turns out what we were expecting. But at the end, when we finally completed our beetle bot, we felt very happy and satisfied.
