Hell On Reels

Tags: mechanical, Innovate, and Design
Personhours: 6
Hell On Reels By Max

Task: Make a prototype grappling hook of doom.

As the point values make clear, managing to get the robot to hang on the end of the "cliff" is likely worth the effort. As such, we've worked on making a strange grappling-hook type contraption to pull the robot up. This first version works rather like a crossbow. A telescoping fishing pole has its largest loop hooked up to a long "bolt" which extends beyond the pole to a bungee cord tied to a pair of arms on the sides of the fishing pole. A 3D-printed grip is attatched to the bolt, and allows it to socket into the bungee cord and be pulled back by a person. When pulled back and released, the bolt pushes the telescoping portion of the fishing pole, causing it to extend.


Reflections

This part is by no means complete yet. There are 3 main issues to tackle before this can be considered finished. First is a trigger. As of yet, the bolt fires as soon as it is released, so we need a mechanism to hold the bungee taught until the robot is ready and in position to release it. The second issue is making a hook. The telescoping portion of the fishing pole hasn't been modified much yet, but we will need to put a hook of sorts on the tip of the pole. Instead of a more cliche three-pointed hook, the most likely solution for us will be something more like a carabiner, so that we can extend the hook directly towards the churro on the cliff and the hook will clasp around it with a spring-loaded bar. The third and final problem will be closing the gap. We have made a way to propel the pole up to the cliff, but we haven't made a way to pull the robot along after it. To solve this, we will probably just use a cable and a winch, like what is commonly on a fishing pole in the first place. This will likely involve tying one end of a string or fishing line to the hook, and then wrapping the other end around a spool on a DC motor mounted on the main chassis of the robot, so that reeling in the line will cause the telescoping fishing pole to collapse back down to its compacted length.

Written on November 28, 2015