Our robot is in its “final” stages before a competition next week, yet it still has multiple flaws that prevent it from being consistent with its intended purpose. Attached are several photos of our robot from multiple angles; the purpose of the robot, programmed on EasyC, is to be able to flip over a cap to the alliance’s color using its prongs (which will eventually fold up to stay within length limits), and then be able to lift up the cap and potentially place it on a pole. The following bullet points are regular flaws with the robot and our team’s attempts to fix them:
1.) The chains on which the prongs are attached to have a tendency to unsnap links at random times, specifically links near where the prongs are attached. We feel this is very likely to be a result of the attachment (screws inserted through the prongs into the links) putting too much strain and pressure on the links, and after multiple uses it eventually snaps. This is one of the biggest issues we are having with our robot, as we cannot think of a better way to attach the prongs sturdily to the chain while minimizing strain and still be able to get the chain over the sprockets.
2.) When the prongs try to lift the cap, it has a tendency, when the cap is absolutely covering the prongs, to bend downwards and cause the cap to slip out. It is difficult at time to get the cap completely situated, especially when timed, so we tried to alleviate this by attaching upside-down screws as “spikes” onto the prongs to catch onto the underside of the robot, but this instead led to the next problem.
3.) If the cap does get lifted, it is usually difficult to get it to slide off of the prongs and onto the ground or a pole. We believe the “spikes” are catching onto the cap too well and preventing it from sliding off without having to shake the robot repeatedly. Yet, if the spikes are removed, the cap aforementioned tends to slip off the prongs, thus creating a cycle our team has yet to fix. In addition, if the cap slides off the prongs, it has a tendency to flip in the process, thereby resetting our progress towards scoring points. We have also recently tried rubber bands to keep the prongs level (not pictured), but these catch onto the prongs and create snags, as well as not really being a major help in preventing the prongs from bending.
4.) The robot is relatively unreliable when it comes to flipping the caps. Our strategy is to try and slide only about half of the prongs underneath the cap and lift, so that the cap gets knocked off balance and flips over to our alliance’s color. Yet, it is rare that this actually happens, as the cap usually just rocks for a few moments before staying still and unflipped. Trying to use more of the prongs either accidentally lifts the cap or gets it caught on a “spike.”
As shown, we sadly need a LOT of help before this robot can compete well next week. Our main questions, then, are what alternatives can we use to get the cap to stay on the prongs besides the counterintuitive “spikes,” how can we lower strain on the chains to prevent snapping, how can we consistently flip a cap and lift a cap (preferably keeping the two processes distinct to prevent accidental crossover), and how we can prevent the prongs from bending down while lifting. Any and all help would be appreciated in trying to fix our robot, and while we are constrained on time, we would also take any suggestions on majorly redesigning our robot to better flip and lift caps (we have a secondary robot to shoot balls and take care of the flags). Thank you all very much!
