Quote:
Originally Posted by Taylor
What is it about mecanums that make them so polarizing? The closest analogy I can think of is scissor lifts - they are generally frowned upon for competitive robotics use, but they don't carry nearly as much hatred (or love) as mecanums.
I've yet to see an "I love mecanums they're the best ever" thread; I've seen many "mecanums are the wheels of the devil" threads. Most teams that use them, do so as a bit of a situational compromise - sure, there isn't as much traction or speed as treaded wheels, but there is the gain of lateral maneuverability for minimal mechanical and programming difficulty, compared to swerve/crab drive.
So why the hatred?
|
I'll explain my hatred of mecanums.
I don't hate them. They are a viable solution to a certain set of problems. Personally, I have not seen those problems as being prevalent enough in FRC to expend the resources needed to do mecum wheels. I evaluate this for every single game/challenge/project. If a mecanum wheeled system is the optimal solution to my problem then I will do it. I will also have criteria for why I chose those since I have to justify the expenditure. After the system has performed (usually end of season) I perform an evaluation of how effectively I solved the problem. Sometimes this comes back positively, and sometimes not so much.
The thing that I don't like about mecanums is not the wheels. It is the people that tout them as the Chuck Norris of FRC drive trains. They have downsides, some of them are quite serious (cost, added weight, added complexity, lack of traction, difficulty climbing ramps, requirement of keeping the CoG in mind, requirement of some sort of suspension...) . They also have some very serious benefits that you can't get using any other system. Too many times have I seen the comment that "mecanum wheel r better" espoused by some student. They aren't. But neither is a 6wd or a crab system or a nona-drive. None of them are inherently better than any other solution. Saying that is like saying that a laser cutter is better than an allen wrench. Yeah, if I am cutting out sheet parts (or birch like one of my EWCP friends) then the laser cutter is more effective for that job. But it won't help me if I need to bolt together my parts. My issue with them is that they are often held up as the solution to a problem rather than the solution to the problem at hand.
I've seen teams use the wheels to great benefit. I won't deny that there are benefits to using them. But if you need a hammer you use a hammer and not an oscilloscope.
I know that is probably a wall of text but just take away the next two sentences:
Evaluate how effectively all your options meet your requirements and choose the one that best fits your problem. Don't pick your solution and fit your problem around it.