Re: Winning Drive Train
 

yeah its as my avatar but give me ur email and ill email u a few of those upclose pics

Re: Winning Drive Train
 

Here you go...

Re: Winning Drive Train
 

ok i sent the photos

Re: Winning Drive Train
 

What's traction control :rolleyes:

612 used a 4 wheel drive with front wheel steering. We don't have any quantitative analysis but on the field it was clear that our robot turned better than other robots who used skid steer (nothing wrong with skid steer, just saying on regolith with a trailer, front wheel drive turns better, on carpet different story).

Re: Winning Drive Train
 

2753, 25, 1902, 1251 all had what I considered the best drivetrains of the year. Solid pushing power with pretty decent speed on all bots. Personally, 25 used their drivetrain most effectively.

Re: Winning Drive Train
 

i think that the swerve drive on 111 was the best drive train for this years game because of how much easier it was for teams with swerve to avoid the defense. 111 won the championship and was able to shine every match because their effective swerve drive allowed them to never be shut down by defense like 67 was very often.

Re: Winning Drive Train
 

Our drivetrain this year worked surprisingly well.
At our best, we have pushed 3 robots at once.
It was just a modified, "wide ride", drop center, 6wd kitbot chassis with unmodified toughboxes and 1 CIM per side.
The only traction control we used, was a ramp up code, that increased the robots speed when moving from a stopped position.
But I think the reason it worked so well, was because of the weight distribution.
The weight on our robot was just slightly forward on the chassis, making us a front wheel drive which gave us greater maneuverability.
But if we got into a pushing match, the weight shifted to the back wheels.
Since our robot was able to rock back and forth, the force applied from our opponent pushing against us, actually lifted the front end of our chassis just a bit.
This in turn, applied downward force on our back wheels, helping us to "dig in" and gain more traction. Thus, we were able to use our opponents pushing for against them.
Now I will say, we did not in any way engineer our chassis to do this.
It was merely something we noticed happened while pushing another robot out of the way.
I don't have any math or statistics to back this up... but I will see if I can get some pictures of it up here soon.

Re: Winning Drive Train
 

Wow, all you guys were only able to push 3 robots sideways? We easily pushed 5, but never did so because we wanted to keep our alliance partners free....:rolleyes:

Actually, I'm on John with this one. Anecdotal evidence and stories don't mean anything; what I've learned from this thread so far is that, A) Every drive type so far is the best, or B) some people are exaggerating.

There is no need to toot your own horn, as most people just flat out won't believe you.

As for this game, i don't think a definitive answer to what drive test is best exists. 111 was an extremely good dumper with crab drive, but was it the crab that made them effective? I don't think so, I think 111 with a 6 would've been just as effective. Not to mention, even though 111 was extremely good, I think there are some other dumpers out there without crabs that are better in my opinion. 67 and 217 are tied in my head (along with a few others) for being the best robots this year, and both showed they were extremely manueverable with a wide 6 wheel. I imagine they drove that 6 wheel better than a lot of teams drove crabs.



In the end, people can throw all the stories at me they want, but I'm never going to let mere stories convince me physics is wrong.

Re: Winning Drive Train
 

Wildstang is a great team with one of the most amazing drivetrains ever seen to first. Their drivetrain definitely helped them win, .(obviously being successful is a combination of doing many things well) but I'm going to argue that more important than that was their ability to hold almost 40 and dump them all out really fast. I think that was the biggest reason they won in Atlanta.

Re: Winning Drive Train
 

Yes, Wildstang had traction control. We used a manufactured wheel with foam as the tread to reduce forces to an absolute minimum. This wheel, on the same axle as the drive wheel, allowed us to compare the two to determine slipping of the drive wheel.
We prototyped several drives and settled on crab again this year. It proved in testing to be more effective in handling the trailer. We found, as many of you did, that the trailer shifted the center of rotation to somewhere outside of the robot. By using crab, we could then put that center where ever we needed it. Crab also allowed us to skid steer when going fast and control the robot when we needed to dump. It is important to note that the bumper rules also played into this. The six inch minimum segment length meant that we could not have a ball pickup that was the entire width of the robot. Since the pickup opening was limited to 26 inches, there was room for crab modules at each corner without sacrificing rapid pickup.
BTW, this is called crab drive because it mimics the way crabs move across the beach. The term has been in use on camera pedastels since the dawn of TV.

Steven,
We could only hold 25 or so, but thanks for the kinds words.

Re: Winning Drive Train
 

Well, I have some info/data about our drive train this year.

It was 4 wheel, linked left/right power and steering crab. Wide side "forward".

It seems that this year wide drive robots had a better time getting around, as well as an easier time not getting pinned.

The crab was really nice for pinning, as well as maneuvering out of tight situations.

We did some tests with a fish scale and determined that the drivetrain itself (120 lb + 15 bumper + 12 battery) can give ~9-10 kg of thrust.

We also had fans on our robot. Using a different setup, we tested each fan to give 2 kg of thrust, without a shroud. Two fans -> 4 kg. Each fan was powered by a CIM directly. In the end, after efficiency loss, the fans together probably output 3-3.5 kg, or an extra ~30-40% thrust. It was noticeable on the field, at least from a driver standpoint. First, it made acceleration much faster. Second it made it easier to stay in contact with a robot once contact is made. Third it makes it easier to hold robots once you get them to a wall.

That's all I have. I hope that's what you were looking for.

Re: Winning Drive Train
 

I agree with Adam. The other question (which hasn't been fully defined) is, Best at what? Offense, defense, pinning, avoiding pinning, etc. Sure, you can build a great offensive drivetrain, but somebody with a great defensive drivetrain may be able to beat you. There is a difference, I'd say.

Re: Winning Drive Train
 

WOW! :yikes: thats for that was alot for me to read on my phone! i had to wait till i came home, but thanks!!!

are we talking about dead stop pushing or full speed ramming? because i can push robots around when at full speed 100% traction.

The problem: The Feild + KOP wheels... what was the best solution? it dosent matter about offensive or devensive. what matters is out of all the different combonations teams came up with, which concept was the most effective? the fan? the 100+ wheels? the programming? 4 wheel tank 1 CIM? 2 CIM? Wide base ?narrow base? etc...
i look at my team with 4 wheel tank 2 ONE CIM each side with KOP gear boxs at 119.8lbs and no traction programming i say this was an avg drive train. not a winning one.
you may be right when you look at playing on carpet, but 2009 was a little different.

Re: Winning Drive Train
 

Look at 330's drivetrain. Defense was their specialty, yet they didn't often pin and liked to score a lot. 6WD, very narrow, sort-of crab, traction controlled. Effective? Maybe. Most effective? Probably not, depending on your definition of most effective. Decent all-around, but not outstanding at any one thing.

And you STILL haven't defined "most effective". Most effective at what?

And with all those combinations you list, you may be right playing on carpet, but 2009 was a little different.

Re: Winning Drive Train
 

This is the most underlooked post in the whole thread. I think it is clear that wide drivetrains were most effective, because they facilitated power dumper robots, which also proved to be among the most effective. Traction control, number of wheels, additional fans, swerve drive, etc. all played into helping teams win, but ultimately the combination of a wide robot with a fast unloading mechanism was deadly. As long as the drivetrain was controllable enough to pick up balls, and eventually pin, that was all that was needed to win. Optionally, playing 'run-away' defense, and combatting against that, was aided by additional features, but was an edge case because usually robots could and would get pinned.