Belt Whip Catapult Robot

SparkFun Full-Bridge Motor Driver Breakout - L298N

MG996

Drill / Driver, Cordless

Arduino IDE

Arduino UNO

<p >I built this project as an introduction into the world of robotics and Arduino. What better way than to have a little fun by taking a classic physics project, a catapult, and using the motion to recreate a belt whip.</p><p >You can keep up to date with my journey through my YouTube channel:</p><p ><a href="https://www.youtube.com/channel/UCYt-FhSLXeQrROdbLOBCZUw">https://www.youtube.com/channel/UCYt-FhSLXeQrROdbLOBCZUw</a></p><p >Check it out in action here:</p><div class="se-component se-video-container __se__float-none" contenteditable="false" style="width: 100%;"><figure style="width: 100%; height: 56.25%; padding-bottom: 56.25%; margin: 0px;"><iframe frameborder="0" allowfullscreen="" src="https://www.youtube.com/embed/4dSmENIJczw" data-proportion="true" data-percentage="100%,56.25%" data-size="100%,56.25%" data-align="none" style="width: 100%; height: 100%;" data-index="0" data-file-size="0" data-origin="100%,56.25%"></iframe></figure></div><p >To start off the project, I made a catapult without any electronics as this will represent the movement of the robot. There are many ways to build a catapult but I chose a simple way by taking a bookshelf and drilling L brackets into it. You can then stick anything straight, chopsticks, poles, or a pencil through the hole to act like a fulcrum. In between the two brackets should be what you want to use as your arm of the catapult. I used a hockey stick. </p><p >Now for the fun part of the catapult. The launching motion. This is done by having 2 eye hooks, one drilled at the end of the bookshelf and another one on your arm. Attached to the hooks are bungee cords which are perfect in this case.</p><figure><img src=https://projects.arduinocontent.cc/e605d94b-7f50-405f-87ca-15d1ac0bd306.png /><figcaption> </figcaption></figure><p >After this, you should be able to launch your catapult at will. It was a lot stronger than I thought and obviously the more tension/bungee cords you add the stronger it will be. Now it's onto automating the process in resetting the catapult as well as launching it. </p><p >To reset the catapult back to starting position, I used a power drill controlled by a L298N motor driver. Any DC motor that is capable of pulling a strong load will work however. Attaching a string from the drill to the hockey stick will allow the drill to pull back the catapult into a "Ready-to-fire" position. But before we fire we need to release the tension on the string or else the drill will also go flying. </p><p >A servo motor is used to hold the hockey stick in place while the drill releases the tension on the string. Once this is done, the catapult is ready to fire and the servo rotates launching the catapult and whipping the belt. </p><figure><img src=https://projects.arduinocontent.cc/31b7af55-5c8c-496a-9ee0-8b4910bc2800.png /><figcaption> </figcaption></figure><p >This process can be done indefinitely for maximum punishment ;)</p><p >If you're still questioning </p><div class="se-component se-video-container __se__float-none" contenteditable="false" style="width: 100%;"><figure style="width: 100%; height: 56.25%; padding-bottom: 56.25%; margin: 0px;"><iframe frameborder="0" allowfullscreen="" src="https://www.youtube.com/embed/shorts" data-proportion="true" data-percentage="100%,56.25%" data-size="100%,56.25%" data-align="none" style="width: 100%; height: 100%;" data-index="0" data-file-size="0" data-origin="100%,56.25%"></iframe><figcaption contenteditable="true"><div>https://youtube.com/shorts/PYxBnGnE6K0?feature=share</div></figcaption></figure></div><p ></p>

Belt Whip Catapult Robot

I built a belt whip robot to punish kids in an automated and creative way... for science