Here’s our robot being suspended from the first rung and reaching for the second. After the second rung the robot transitions to the outside of the third rung for the final climb. Speed is the biggest issue currently as the lead screw mechanism we’re using is only climbing at 50 inches per minute. As crazy as it seems we’re also thinking about ditching the drive train and just climbing.
What are you using to hook onto the first rung?
It’s a steel spring loaded hook that pops out as the climbing shuttle pulls the robot up to the rung. Then the shuttle is free to move back the arm ready to reach for the next rung.
My question is if you’ve tried this with bumpers. Bumpers might make that climb a lot more difficult.
Yes, we’ve tried it with bumpers. That’s one of the reasons the bot is only 15 x 24 inches.
That’s one small robot.
Video? PLEASE:D
It may be worth trying normal wheels instead of mech’s before ditching the drive train all together
After thinking a lot about the drivetrain we’ve decided to keep it. An essential element of the design is CG manipulation. The majority of the mass is low in the robot base (4 CIMs, 4 Banebot p-80s etc). The arm is coupled to the base via a CIM/256:1 P=80 gearbox. Changing the relative orientation of the arm to the base while hanging is what controls the arms orientation to the tower. Said more simply kicking that heavy base back and forth controls where the arm goes.
This picture was meant to be a ‘clue’ not a ‘how to’. That said, we’d be glad to answer any questions and share details with anybody trying to make a similar concept work. This has and continues to be an evolutionary process from the crazy idea we had right after kickoff. Our design criteria are something that’s unique, simple and elegant. That has lead to a lot of sleepless nights but after all this is FIRST!
If you want to see all this in action we’ll be at the Colorado scrimmage a week from Saturday.
This is cool! I’m kind of relived you kept the drive train, although part of me really wanted to see a sucessul robot without one. Good luck, and let us know how you do!
A robot that climbs reliably for 30 points every match is not a bad alliance partner at all; can you pre-load colored discs, and dump them in the hopper at the top of the pyramid at the end of the climb?
This strategy may not make you the #1 seed, but **will **outscore lots of other teams that fail in/don’t have autonomous, can only do a ten point climb, and end up only scoring five or six three-point discs in tele-op. And it could do so reliably, every single match.
This may outperform a robot that tries to do everything, and ends up doing nothing well.
Colored discs start behind the corresponding alliance wall. You could design a robot that could be loaded by another robot for a dump but it’d be difficult for consistency between qualifications of a robot that can fit your needs.
Oops, sorry.
We initially thought about colored disk in the top goal but quickly ruled them out for the following reasons. First, the base of the robot only gets above the second rung. Second, you’d have to go to the feeder station to get them. Third, you have to have a way to transport and place them. An the list goes on and on. Translation, it’s not worth the extra 20 points. In fact in figuring out match tactics within our strategy, there are going to be situations where a 20 point climb will be all that is needed. As many of you have pointed out, one of the most important aspects of this year’s game is reliability. Why would you want to make the robot less reliable by trying for 20 more points? We want to do one thing well. We’re not greedy.
To address the three bold points:
“the base of the robot only gets above the second rung.”
Not necessarily true. The base of the robot, at a minimum, gets above the second rung. It is entirely possible, though not likely, to design a robot that practically hugs the rungs and gets you as high off the ground as possible. As well, the scoring mechanism doesn’t have to be at the very bottom of the robot, and I would be quite surprised if it was at the very bottom.
“Translation, it’s not worth the extra 20 points.”
Hugely debatable. It’s a fairly reliable system, and addressing the point above, even if you’re barely above the second rung, you’re still closer than ever to the goal. (<36" to the goal.) To put this in perspective, 20pts of white discs would mean 2 full trips (or hoppers) with almost perfect accuracy (you can miss one shot out of 8. Meaning you shoot with 88% accuracy.)
“A 20 point climb will be all that is needed.”
I cannot speak for other teams, but for our team, it would be fairly difficult to stop at the 20pt level, unless we run out of air or have catastrophic failure. It is designed fairly autonomously and will more likely than not be a 30pt or bust climber.
CalTran, Your points are well taken. Perhaps the biggest reason of all against doing it is : If you can reliably show you can score 30 points every match, as soon as you leave the safety of the pyramid your dead. Every robot on the opposing alliance is going to be focused on making sure you don’t get back to the pyramid. Keeping you from climbing is the same as them scoring 30 points.
Do you think that a team who is that dependent on their strategy would allow themselves to be blocked away from the pyramid all game? I would only hope that the drivers are able to free themselves just enough to get back to the pyramid or that another alliance bot would be able to take the blocker off for a few seconds.
I guess that I am basically saying, do you think that you could prevent a robot from getting to the largest object on the field for a long enough time that it stops their climb without sacrificing defense on what are hopefully that alliances “main” scoring robots (the shooters).
I think your mecanums might be on backwards- the rollers form a 0 instead of an X.
Question 1 - Why leave the safety of the pyramid if all you need is the 30 points?
Question 2 - What do you think the other robots on my alliance are going to be doing?
Stopping you from stopping me from scoring 30 points is the same as them scoring 30 points and you scoring 0! 
Either way, my alliance wins by 30 points!
Good eye Brandon, Right now the drive train is not hooked up and is only dead weight to make CG manipulation work. If you’re keeping up with the discussion the question is do we even need to make it work. The robot rules say you have to have a ‘mobility’ system. They don’t say it has to be functional. As it stands now our match strategy is to position the robot at the start of the match inside the pyramid with the arm touching the first rung. Then in autonomous the robot will climb to the first rung and hang. When teleop begins it will climb to the second rung, transition to the outside and finish the match hanging in level 3. The sticky wicket right now continues to be climbing speed. During the 2 minutes of teleop it’s dicey completing the L3 climb, hence starting in autonomous. We’re looking at other climbing motor/gearbox combos to make the climb faster. The current climb mechanism is a 36 inch 1/2 inch 0.25 lead screw run by an AM-0915 gearmotor. That spins the lead screw at close to 200 rpm climbing at 50 inches per minute. We’re looking at using a BAG motor/Vex Pro gearbox setup.