Designing Ping Pong Ball Launchers !
Hey guys! Upon the completion of Task 1 : Modelling the Elegoo Tumbler Robot on Solid-Works, we must begin Task 2 : Designing our very own Ping-Pong Ball Launching Machine !
I have breathed life into the Robot, she is assembled (YAY 〜 blog coming soon!) and is awaiting to be programmed via Arduino to be able to manoeuvre a simple obstacle course autonomously.
The Ping Pong Ball Launcher awaits at the end of the obstacle course, and our Robot must catch the greatest number of ping-pong balls launched within 20 seconds, before leaving the course !
✰ The Ping Pong Ball Launching Machine must comply with certain critical constraints :
- The Energy Storage System embedded into the device must convert Potential Energy to Kinetic Energy, or the Ping-Pong Balls must be launched by a Pneumatic Force.
- The Energy Source must be ‘loaded’ at the beginning, implying that the provision of supplementary energy into the system, upon the start of the Robot’s journey through the obstacle course is not allowed.
- A system of automatically re-loading Ping-Pong Balls must be incorporated into the device, as the manual re-loading of the next ball, upon the prior being fired, is also advised against.
○ Idea #1 → SPRINGS !
Upon being towed backwards, the springs become compressed, and accumulate Potential Energy (Ep). When the springs are released, the energy is converted to Kinetic Energy (Ek), and the ping-pong ball is fired.
Springs are very desirable, as they are believed to produce a consistent force each time, once compressed to the equivalent extent. Formulas from Leaving Cert Applied Maths can be utilised to determine the trajectory and the horizontal displacement of the launched ping-pong ball 〜 very valuable, as the positioning of the Ball Launcher and Robot can be approximated accordingly.
However, the accumulated energy is exhausted each time the springs are released, and therefore it does not accommodate the ‘loaded’ energy source criteria.
○ Idea #2 → ELASTIC BAND !
Likewise, the elastic bands are in a state of tension when stretched backwards via the string, and are subject to Ep → Ek conversion upon being released, firing the ping-pong balls.
However, we confront similar issues yet again, as the energy source is depleted after each ball, and there is no feasible method to preserve the energy and consume it gradually.
○ Idea #3 → INSPO FROM A MANGONEL !
Inspiration for this model was derived from the Mangonel Project in First Year, and the functionality is based on the operating principles of Catapults or Sea-Saws!
And again, we come upon the same complication 〜 an exhausted energy source!
○ Idea #4 → PNEUMATIC FORCE !
The recent stormy weather inspired me to incorporate Pneumatic Forces (strong air) in my Ball-Launcher designs !
The inwards motion of the plunger displaces the formerly-occupied air, resultantly firing a ball. The fixed volume of air evacuated each time helps to maintain consistency with every trajectory, however the force applied on the plunger is also an important influencing factor, and it is subject to variation each time - it is a parameter that is hard to quantify.
The adequate exertion of force to launch a ping-pong ball requires the energy source to be drained each time 〜 given the limited volume and low pressure of the contained air. So, we encounter the same issue yet again 〜 but I think this is one of the more promising ideas that can be further revised to actualise our final design!
○ Idea #5 → COMPRESSED AIR !
For the first revision of Idea #4, I decided to derive inspiration from the various lockdown-birthday props I had at home!
The gradual release of air from a Plastic Helium Balloon, regulated through a valve is one of my better ideas in theory.
Yet, I am afraid that the modest volume of air, coupled with low air pressure would amount to an undesirable trajectory. A substantial weight must be placed on the balloon to generate a higher pressure, as P ∝1/V (Boyle’s Law), for more desirable results, but the feasibility of the theory is debatable.
Moreover, pressure fluctuations in the progressively deflating balloon would deteriorate results with each trial, lowering the accuracy of the Ping-Pong Ball trajectories.
However, one more revision is pending !
○ Idea #6
Some further reconsiderations of the Ping-Pong Ball Launcher design have been made upon careful analysis and consideration ! (this is my final design, bar any unforeseen complications 〜 fingers crossed シ)
[[It is now 16th April and I am laughing at how oblivious I was …]]
○ The weak balloon is replaced by a canister of Compressed Air to act as a stronger Pneumatic Energy source, with consistent air pressure throughout, and an integrated nozzle to manually control the release of air.
○ A flexible Mounting-Stand is incorporated into the design to conform with the dimensional guidelines [ Height < 0.9(height of a 500ml Coke bottle) ].
Further details of the process of building the launcher is upcoming in my next blog!
Little Spoiler :
My ‘final’ idea as I have so optimistically described above did not work at all at alllll ! [It failed to the point where my sneezes were launching the balls further…] But nonetheless I am glad to have documented all my ideas - and hopefully I am able to devise a plan for it soon because the deadline is slowly (fastly!!!) approaching !
Stay Tuned please :)
