Fire Fighting Robot- Part 5 Shaker Idea

Esther and I had to think of another way to put out the candle using our mechanism. We realized that our mechanism was not good at pulling things, but it was good at pushing things and at moving back and forth relatively fast. We decided to focus on the strong aspects of our mechanism and we transformed our mechanism into a shaker. We thought about having something shake something over the candle that would put it out. It is relatively easy to put out a candle with baking soda and it is lighter than sand, so we decided to use baking soda.
In order to make a shaker, we made a piece on SolidWorks that would attach to our mechanism. We designed that extra piece according to a box-like plastic piece that we found in the engineering lab. We drilled holes in this plastic piece that small enough so that the baking soda would not just fall out while the car was in motion and large enough so that a decent amount of baking soda would sprinkle out as the shaker was shaking back and forth. In our design, the plastic piece would just fit on the delrin piece and we could remove it whenever we wanted. We attached this new delrin piece to the our mechanism by heat staking them together and this proved to be very effective because our new shaker was very sturdy. Here are some pictures of our new shaker:
As you can see, the shaker requires less support and reinforcements than with the spritzer idea. This was very nice because we could reduce the amount of Lego pieces we used as well as the overall weight of the MotorCar. We could also have a clear view of the breadboard and it made it easier for us to change wires and to connect the motor powering the mechanism to our breadboard. We were able to see very quickly how much easier it was going to work with this shaker idea rather than the spritzer idea and how much time we would save trying to make it work.

Here is a close-up picture of the new delrin piece and the plastic piece:
Here is a picture of the what our robot looked like after we finished attaching the mechanism to the robot:
To connect the NXT motor to our breadboard, we had to go back to one of our LogoChip challenges. Since these motors are designed to use a 9 volt power supply, we needed to supply it with more power and in order to do this we wired a transistor to power our NXT motor. We connected it to pin P3, so in order to turn it on and control its speed with PicoBlocks we used the "setpower3" command. We reduced the power a bit because with full power the shaker was shaking way too fast.

Now we had to figure out if it actually worked! This was the moment of truth and we were pretty nervous because we had been spending a lot of time trying to put out this candle and if it didn't work, we would have to spend more time making new reiterations.

But it worked beautifully and it put out the candle almost instantly. Here is a video of it:

As you can see in the video, the shaker is moving rapidly and that is because we removed the extra gears because now our intent was to create a fast motion and not a strong pull.

Another good thing about this mechanism is that it is very stable and even with this rapid motion, it did not fall apart. The only concern that we had was that most of the weight was on the right side and we didn't want the car to topple over. So I added some more Lego blocks to the left side of the car in order balance the car a little bit.