We’ve been debating how to build our drive system for FTC this year. We’re waffling between tank drives, a hybrid "half track design with the tracks in front and wheels in the back, a physical crawling style system (like a beetle), or just not dealing with climbing at all while trying to maximize points via other means.
Has anyone else worked through this quandry or are we the only team bending with the wind, prototyping our rear-ends off and generally being frustrated.
Any pearls o’ wisdom would be appreciated.
PS: We’ve watched multiple videos and tried various combinations of wheels. They’re lame in comparison to tracks. (at least today…lol)
Thanks for any help that could be given on this.
Steve Miller
Coach Team 10756 FTC
Coach Team 3355 FRC
You definitely aren’t the only team having trouble with the mountain. I think a lot of teams are either underthinking how they’ll climb the mountain or overthinking their capabilities.
I’d recommend coming into designing your drive train knowing what you want your robot to do. There are a number of things that go into that-- when is your first tournament? What do you want to spend most of your time working on? Do you and your students have a solid grasp of drive mechanisms and the physics involved?
Based on videos and my team’s experience, you can get up to the middle zone fairly easily with wheels, but getting to the high zone will be significantly harder. We decided that we weren’t even going to worry about the high zone for our first tournament (December 13th), because there were more (and easier to get) points elsewhere in the game.
Having said that, there are a number of things can can make climbing to the middle zone with wheels smoother/easier-- making sure you have your weight in the right place, making sure your wheel spacing is good and your wheels are properly sized, et cetera. Many of the prototypes I’ve seen for climbing seem to have really narrow wheel bases, which might be nice for turning but won’t help with the mountain.
Another suggestion would be to actually physically try your own drive trains out-- if you don’t have or can’t afford a mountain of your own, you might try reaching out to another team and asking them if you can come over during one of their meetings. CAD can tell you a lot about the mountain, but (at least at the level most FTC and FRC teams are at) it can’t substitute for physically trying your ideas on the mountain.
You don’t need to drive over the churros to score in the goals or to climb in the end game. You just need to drive on the mountain with your drive train above the white tape at the bottom two inches. There are lots of ways of doing the rest of the scoring from this position.
Virtually all of the tread-based drive trains that I’ve seen are all VERY low and even then they nearly all tip back over when they are in the high zone. I see a lot of videos with folks driving up in the high zone while somebody has their hands there to catch the robot. I don’t see a lot of videos with these robots sitting entirely in the high zone or driving back down without tipping over. If they add other mechanisms on their robots above their drive trains, it may be VERY difficult for them to keep their balance if they dare to go into the high zone. I suspect most will stick to the mid-zone at most. The mid zone is worth 10 points more than the low zone in autonomous and the end game, which isn’t much compared to putting a few pieces of debris into the goals.
It isn’t legal to purposely deposit debris on your opponent’s side of the mountain. However, I suspect that debris may end up there accidentally when teams are trying to score and miss the goals. The debris will then be stuck on the mountain by the churros. If your goal is to drive over any of the churros, make sure your drive train works when there are blocks or balls resting on the mountain by the churros, or you may find yourself unable to get as high as you planned.
Our team is just going to the mid zone and scoring from there. I think that having a system that can consistently dump lots of debris is far more important than the few points you get for being able to drive to the high zone.
Climbing the 30 degree section will take some work but many teams should be able to accomplish it. The 50 degree section is another story. The problem is center of mass and the torque force from driving the wheels makes the robot want to rotate off. Tracked robots fair a little better but as soon as parts are added to accomplish other tasks the COM goes bad. Even if a tracked robot is designed and can climb the mountain there is the problem that driving on the floor is terrible and many solutions to the mountain destroy the tiles in the required test. Yes, This is a very tough challenge. As others have said there are many other ways to score with out going all the way up the mountain.
Our team is obsessive about climbing the mountain and have gone thru the calculations, prototyping and tested several solutions. The robot is designed. The kids have been making parts for weeks. The robot is 1/2 way assembled. Will it climb? Time will tell. Even if it doesn’t. It’s amazing how far these crazy 7 and 8TH graders have come. I think we accomplished the FIRST mission already.
Our team, as well as most others we know, seemed to determine mountains = most-point potential. But, as the game was designed, it comes with far-higher risks.
Watching another team practice-- with my ref’s hat on-- I wanted to point this out: watch how fast and far you move your robot up the mountain, especially if you want to establish yourself in the High Zone before the End Game. If the robot needs to go at high speed or as high as possible-- or drivers choose to drive it so-- your robot might overshoot and engage the Cliff low bar enough to nullify scoring End-Game scoring achievement possibilities for your Alliance on that mountain. If you plan to build and operate to climb high, be sure it can be done to avoid contacting the Cliff’s All-Clear Signal, Pull-Up Bar, or Low Bar before the End Game.
See section 1.5.4 and <GS18> of Game Manual Pt. 2 for details.
You’re welcome, DD. To add a bit more, it’s a matter of-- in Rules-speak-- Inadvertent / Inconsequential. We’ll see how we interpret in our tournaments, but theoretically refs would warn if the robot is getting close to contacting the off-limits Cliff elements (signal, pull-up bar, low bar). If contact increases or continues (e.g. “wheelies,” support on the Cliff Low bar), then that would constitute breaking <GS18> and 1.5.4 and should be flagged, with the nullification of that Alliance getting End-Game Cliff achievement points on that mountain.
The upshot-- if teams want to establish High-Mountain position before the End Game, do so in a manner without contact/support of the Cliff. It seemed the violations I saw were products of “gunning it” to get up and stay in the Mountain High Zone. I would think as robots are tweaked and drivers get more experienced, potential for this will decrease.
Here in Arizona, the refs would classify a quick touch as Inadvertent or Inconsequential. If the Robot actually used it, to hold itself up, or to pull itself up, then they were called on it.
Teams can probably get away with hit the bar a few times in the beginning, but as the day goes on, and the season goes on, refs are not going to be nice on that.
If a team has a lift that moves pretty quickly, they should remember that. Maybe work on slowing it down, or having it automated, so it wont touch the bar.
Summary of what I saw re: climbing while reffing @ our state’s second qualifying tournament of the season…
In short, most action was at or below the Mid-Zone; very few rested on the highest heights. (One robot got on the pull-up bar x2, one got in the High Zone [also, I think, in two matches] by hanging on the Cliff low bar.)
As was mentioned up-thread, the majority approach seems to be get to the Mid-Zone, and establish yourself solidly there as best and as high as you could. Getting in the High Zone seemed too tough to do/try for vast majority. Along the way, attempt to trip first and second zip line triggers (modest success from attempts-- almost all were the first trigger only) and score in mountain goals (little attempts, about 33% of scoring in maybe 6 tries), and from there attempt Cliff achievements. I saw no attempts to trip the highest zip-line trigger.
Also did not see what I cautioned against earlier… no robots hit the mountain with a lot of speed in attempt to get as high as possible. Teams learned early that debris foils best-laid plans and they needed to combine enough speed to get onto the mountain while maintaining control.
Tournament winners/high placers were teams that consistently: got at least the minimum points from Autonomous*, was better than .500 at getting climber(s) in the shelters (most done while under driver control), moved some debris into the floor goal, a low zip line trigger attempt, and got into Mid-Zone… often going to the opposite Alliance’s side.
*I’d guess half or more of the teams I viewed weren’t ready or didn’t want to risk things, so sat still in Autonomous. My partner ref and I joked about the stress of scoring in the several cases of an Alliance having two non-moving robots. Again, it’s early in the season.