I've been involved in robot combat (BattleBots) for the past three years now. My first robot Shish-Kabot was extremely successful with one 2nd place and two 3rd place finishes but it had one weakness. Every time it fought a flipper robot called Upheaval, it would get tossed around and lose via knockout. (see 2nd image) After spending way too much time thinking about how to beat Upheaval with Shish-Kabot I decided to build a better flipper bot...
Step 1: Background
I guess I should probably explain a few things about what I'm talking about.
Robot Combat is an sport often referred to as BattleBots, but that term is trademarked so I'm probably not supposed to say it. But the basic idea is two robots fight to the death in an enclosed bullet proof glass box for 3 minutes or until one can't move anymore, when a knockout is declared. There are basically three groups all robots can be categorized into. Spinners are probably the most prevalent. They have some spinning mass (think exposed lawnmower blade) and try to slice or blunt force the other robot into submission. Pushy bots are the simplest to build. They often have a wedge to get under the opponent. They win by dominating the flow of the fight. The third group is flippers or lifters. They are designed to get under the other robot and flip them over or chuck them across the arena and hope something breaks on impact. This is often done using pneumatic rams. Flippers are not very common anymore because the introduction of cheap imported Chinese brushless motors and the difficulties associated with pneumatics.
The design goals/constraints for Phoenix were
1. Powerful flipper weapon
3. Cost must be under $700 (I'm a high school student without a high paying job)
4. Must be under 30lb weight limit