Quote:
Originally Posted by JVN
Does anyone have any quantitative measurements of their performance, or are we basing everything off anecdotal evidence (as usual)?
Yep, 703 was great at pushing in 2007. They had an incredible defensive machine. Yet... I bet that NO ONE made any quantitative measurement of it's performance. Here is what I would looooooooove to see: - Step 1 - Measure it's linear pulling force while on carpet (use a fish-scale).
- Step 2 - Remove all but the 4 outer wheels.
- Step 3 - Throw the extra wheels on top of the frame, so the overall robot weight doesn't change.
- Step 4 - Measure it's linear pulling force again, while on carpet.
I speculate that these numbers will be extremely similar. Within 5%.
Maybe I'm wrong. I would love to be wrong. I would LOVE for someone to prove me wrong with some solid engineering analysis beyond the usual "703 pushed really hard, they pushed against truck town and everyone knows that nobody pushes truck town..."
Anyone? Anyone? I'd be genuinely happy being proven wrong. I don't have the time myself to do the kind of testing I'm talking about.
Absolutely. If the students decided they wanted to do something "just because they want to" even if it doesn't pass our cost-benefit analysis, I would need to respect that decision.
However I'm chuckling to myself, because I don't really believe our students would ever force me to back up that statement. I guess I'm lucky that our school district's values, our sponsor's values, team's values, our student's values and my values are all pretty much in line.
Then again... maybe it is a pied-pipe type of thing...
Moral of the story, you'd have difficulty finding a Robowrangler who has a bad experience, and our program keeps our sponsors, parents, school, and community happy; I can't really ask for anything more.
-John |
John, I was by no means suggesting that you wouldnt take students into account, merely showing a valid reason to do something like this. I apologize if my statement was taken that way.
Now, about the evidence, after reading the threads about their drive train their goal was to get the benefits of a tread without using tread, did they meet their goals? For that answer you would most definitely have to get one of them. From my perspective they achieved their goals, 1) eliminate the ability of breaking a tread if pushed sideways. 2) They had an incredibly low cg and still did not bottom out climbing obstacles. They proved that a large number of wheels gives you those benefits. They also proved that the draw back was complexity and weight. Did they gain any additional pushing force out of it? Probably not. Would they have been able to shove us around without 14 wheels? Most likely, but the fact remains that they DID gain an advantage from doing that many drive wheels.
What teams need to take from this discussion, in my opinion, is that there are situations in which 8wheel drive would be effective, there are times when 3 wheel swerve would be effective. You wouldn't try to tighten a bolt with a hammer would you? Always weigh the costs with the benefits and use the appropriate tool for the job.