GEARS

 Hello everyone, Wei Ling here. Today we'll be talking about GEARS!! so to get things started, let's first talk about the  definition of gear module, pitch circular diameter and the relationship between gear module, pitch circular diameter and number of teeth. Gear module indicates how big or small a gear is, pitch cicular diameter is the diameter of the circle of the gear itself. The relation behind gear module, pitch cicular diameter and number teeth is as followed m = d/z, where m is gear module, d is pitch circular diameter and z is number of teeth.

Let's also talk about elationship between gear ratio (speed ratio) and output speed for a pair of gears. Gear ratio can be calculated by using number of teeth of driven gear over number of teeth of driver gear, and the smaller the gear ratio, the faster the output speed.

Let's dive into the activities conducted in the practical. FIrstly, we'll talk about the assembly of the hand squeeze fan. The fan came with these components:

Putting together the parts of the fan was fun but frustrating as well. It was fun it felt like we were playing with lego bricks, trying to fix parts together to what we want. However it was also frustratng because the parts were very loose, so when we picked it up, it'll start to fall apart, and the fan works the best lying flat on the table, which meant that it wouldn't serv it's purpose of a hand held fan which is kind of dumb. 

Here's how it looks like after assembly:

and here's how it work.

let's talk about the assembly of gears for activity 1.

Firstly for assembly of gears, we were considering do we want to make it torque-driven of speed driven, and of course if we want to use the least force we'll then need to use the configuration that is more torque driven. How do we achieve it then?

we tried multiple configurations, trying to get maximum torque possible. Then it came to my mind, if i want my gear ratio to be bigger for it to be torque driven, I'll just have to put a gear that is bigger after the smaller one to make sure that ratio is always getting bigger. Hence we tried that out and got a gear ratio of 26.67:

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Hence from the calculations, when the driver gear is cranked 26.67 times, the driven gear at the end (the gear holding on to the bottle) will then rotate fully once.

   

 Then we proceed on to setting up the gear

Here's a video of us cranking the gear set up:

Reflection: 

This practical allowed me to learn a lot more about gears, though we breifly touched it in last sem during ICPD, when we were learning about mechanism, it was still quite an insight. Prior to this practical, I actually had no clue to like gear module, pitch cicular diameter and things like that. I only knew how gears looked like and how it could probably work. This practical really taught me how to maximise the use of gears and how to use it to our benefit. Like if i did not learn about gear ratio, the thought arranging the gears with the bigger gear always after a smaller gear would have never came to my mind. Overall, it was definitely something new i learn and would apply to future projects.