Blog Entry #6

🏓 Ping Pong Launcher 🏓

    Coming up with the design was honestly slightly difficult as we had to look at multiple reference pictures to come up with a suitable design that fit the requirements. Additionally, a lot of the designs that we came up with would only fulfill only one of the requirements and so, this task ended up becoming more time consuming that I had initially expected. In the end, however, I would say that we managed to apply what we had learnt about operating principles and mechanism design into our version of a ping pong ball launcher so yay 😀

Propulsion Principle:

The toy follows a design similar to a bow and arrow where the rubber band acts as the energy stored mechanism to launch the ping pong ball. The user manually pulls back the handle which stretches the rubber band. The handle is connected to a piston which will eject the ping pong ball when the user lets go of the handle.

Ball Loading:

When the handle connected to the piston is pulled back, a ping pong ball is allowed to fall downwards ↓ into the launching area.

Sketch:

• The handle connected to the piston is pulled backwards to retract it.
• When retracted one ping pong ball will fall downwards ↓ into the launching area by gravity.
• When the handle is released, the stored energy within the rubber bands will eject the ping pong ball, effectively launching it.

🔮 Practical 4 🔮

This practical is about designing a cardboard marble run machine as a team in 2.5h where the requirements are as follows:

• One manually operated mechanism must be incorporated
• The marble must be in continuous motion for at least 30s
• Dimensions MUST be 100cm x 100cm x 100cm
• Structure must be made predominantly of corrugated cardboard

Before the practical, my group had planned to create a few components for the machine which included:

1. A pulley system
   
   
   
2. A carpark-esque structure
   
   
   
3. A structure which resembled a Plinko game
   
   
   
4. A funnel structure
5. Slides
   
   
   
   

Some joineries that we had used are:

1. Flange
2. Tabs
3. L-brace

Here are some pictures for visualisation:

Front view

Side view

    Practical 4 was honestly one of the most painstaking and arduous practical we had done thus far for a multitude of reasons. Before the practical, we had decided to pre-build the components with the intention of saving time during the lesson itself. However, despite every single member coming prepared with their assigned components, we still did not manage to complete the machine within the stipulated time. This was because we ran into an abundance of mishaps while trying to combine our components together such as the marble stopping midway through the obstacles due to not having enough energy. As a result, we had to keep making constant adjustments to the height of the machine multiple times which was extremely frustrating 😭. Moreover, we struggled so much with trying to reach the requirement of the marble being in continuous motion for at least 30s as it was too fast. 

    Halfway through the practical, our team's morale was quite low as nothing seemed to be going well and we ended up exceeding the time that we were given by over an hour 😞. Thankfully however, with everyone's combined efforts, we managed to finish our marble run machine at the end of the day. 👍

The Result: