PBL Reflection

1)How did you use the design cycle in your testing and refinement?
While building the pet feeder, my partner and I found the design cycle really useful. It was the way we naturally did things when a problem occurred. Although we would sometimes skip a part called “feedback” , we were still able to improve our design.

2)Evaluate the effectiveness of your model.
We can not calculate the effectiveness of our model.The type of energy being used in the pet feeder is chemical energy. The chemical energy is coming from a battery. When the energy goes to the clock motor, the motor moves resulting in the board moving.

3)What did you learn about your machine that was “deeper or more effective learning while developing your model?
Although having the correct blue print was important, through out the project I learned that researching was actually the most important thing. Researching helped us in many ways. The way it helped us the most was when we had to decide the amount of dividers to put down. If we did not research, we would be stuck on a step, resulting in an incomplete project.

4)If you had the chance to do this project again, what would you do differently?
If my partner and I had to do the project again, I would make sure that we had a tin that was large enough for heads of all sizes. As I said before, I believe that the sections of the pet feeder are too small for a pet’s head to fit. Another thing my group would do differently would be handling the materials with a lot of care. Throughout the project, my partner and I experienced a lot of parts breaking apart. When the materials broke apart, it resulted in spending more time to fix the part rather than completing the project.

5)Discuss how this project helped you better understand the meaning and importance of creativity, resilience and collaboration for success.
Creativity was a key part in creating the project. If we did not have creativity, we would not get a ME for the ideas grade on our rubric. When the project was introduced to us, we had two options. The first option was to take something and make it better. The second option was to invent something new. Both of those options required creativity because you had to think of new things. For PBL project, we had about two weeks to build it. At first, it sounded like a long time, but when we started building, it went by quickly. Because of a time limit, we had to have resilience. When a problem occurred, we had to quickly think of an alternative or else we would not be able to finish on time. Not only creativity and resilience was important, collaboration was also crucial. In the beginning of the project, only one of the two of us would be working. The other one of us would be watching the stuff that was going on. But like I said before, we were limited by time .Quickly, We found out that we had to divide and conquer in order to finish the project on time.

Thickness of the Cardboard (PBL)

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The table above shows the thickness of the cardboard and if the motor is strong enough to move it. To make the 6mm cardboard, my partner and I had two glue two sheets of 3mm cardboard together.The hot glue was 1 mm thick. All measurements are rounded to the nearest mm.

Problems and solutions

Problem:The second hand broke
Solution: We superglued the part back on.

Problem:We couldn’t get the clock motor out
Solution: We used a hammer and a knife

Problem: The paper clips/nails were too long
Solution: We changed from nails to paper clips. When the clips were too long, we used wire cutters to cut them.

Problem: 2 Nails/paper clips kept falling out
Solution: We used both glue and tape

Problem:The container that held the clock motor was too high
Solution: We lowered the sides with scissors

Problem: The dividers would not fit into place
Solution: We cut them

Problem: The cardboard was too heavy
Solution: We found another piece of cardboard

Changes Made During The Project

Instead of using….

-wood — we used cardboard (recycle)
-using 2 nails –we cut a little piece of the paper clips (the nails were too long)
-Cutting the tin — We used the plastic top of the clock (It was safer than cutting metal and we were also recycling)
– using glue gun –tape and superglue (Because we used the plastic disk, we could not use the glue gun because it would melt the plastic)
– Using thick cardboard — Thin Cardboard (The clock was too weak to move the board so we had to cut different circles out. It took 3 cardboard circles until we got it right.)


Pictures of Pet Feeder – 11/03/15

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We finished building and assembled today , the only problem was that the pet feeder would not move.

Descriptions of pictures from left to right.
1. The inside of the feeder
2. The motor that is suppose to go inside the feeder
3. The motor with the circle/lid on top
4. The circle/lid
5. What the whole thing looks like after it has been assembled

Plan For The Week


-Empty the cookie tin
-Break down the clock
-Research more


-Divide the cookie tin using cardboard
-Make a circle using cardboard that fits the top of the tin
-Level the box



-Finish the top part of the box
– Attach minute hand to the little cardboard piece
– Make sure it fits
-Nail the nails in




-Finish cutting the cardboard (Siwon)
-Finish taping the cardboard pieces (Sheung Yee)
-Draw lines (Sheung Yee)

-Put everything in place (Siwon makes the top, Sheung Yee makes the bottom)
-Arrange the clock hands ( Siwon second hand, Sheung Yee hour and minute hand)

-Assemble everything (Both)
-Test (if possible ) (Both)
-Fix  (after testing) (Depending on which parts)

-Test (Both)
-Fix (Depends on which parts)

Ideas/Questions for PBL


-Water fountain



-Water bottle warmer

-Vending machine

-Flash light

-Phone charger

-Pet feeder

-Brush washer

-Wind turbine



-How do we make a clock motor stronger?

-How do we make the project?

-How much force is needed to push a board?

-If we use wood for the project, how are we going to cut it into a perfect circle?

-How do we record data if we are making a pet feeder?

-Where can we get a clock motor?

-Can we make a clock go faster?

-How can we make objects move?

-How much does cat eat?

Simple electric motor

A while ago, Ms. Chan (our science teacher) told us to build a simple motor out of everyday items. This motor was made out of a magnet, cup, copper wire, clips,  and two paper clips. The original instruction called for batteries, rubber bands and two magnets, but to be more eco- friendly and safe, Ms. Chan made us replace the items. This motor will work only using a low voltage (3), but to make it spin faster, I used 5 volts. Sometimes if my motor went any higher than 2, then little sparks would start appearing around the paper clips.

Above, there is a short clip showing my motor working. Enjoy