Our dimensions (before bumpers) are 22.5 x 24.5 x 35.5, and we have discussed the potential for falling over. Luckily, about 80% of the weight here is within 8" of the ground, and that only looks better when we add bumpers and a battery.
We took a lot of inspiration from 111, 1918, and 2775’s 2009 robots here.
Thanks for letting us know, with such certainty, how our robot will perform. I can only assume you’re building the exact same robot and have already driven it?
Without going into too much detail about our game analysis, we identified 2009 very early on as our primary year of focus in robot design.
That ramp (elevator carriage) is supported on each corner by a 3D printed bracket bolted to a linear bearing. The bearings are each riding on a stainless steel rod, one in each corner. The current plan is to have a run of #25 chain on either short side of the robot (two total) and bolt the chain to the carriage. Idler sprockets at the top of the robot will be connected by a shaft and we’ll tuck a gearbox in the drivebase to power it on one side.
There will be a cut out in the front of the ramp. Another roller will go between the white intake roller and the first black dump roller. The intake roller and this new roller will be wrapped together with polybelt. Behind these rollers we’ll have a vertical wall of material that will cause the balls to roll up and then out and down onto the ramp - we’re calling this the “Waterfall”.
The cut-out piece of ramp will be re-attached with a hinge to act as a “trap-door” that folds out of the way when the elevator is in the floor position, and folds back down when the elevator lifts the ramp to score in the low goal (between the two black rollers) or dump into other robots (above the top black roller).
Thanks Derek - please follow the Facebook and Twitter for all media! I’ll have my DSLR in the shop near the end, we still have a lot of work to do. Your sheet is looking sick so far!
Some background on this team: very intelligent and enthusiastic kids and mentors, very little school support. This robot is built with COTS parts and only manual hand and power tools. 3D printing helped a ton filling in the gaps!
We also only meet three days a week, of which we lost 3 to snow days, so things have e been tough.
I’ll make sure the kids update social media often. Thanks for the support!
I’m a little worried, but not too much. There’s maybe five pounds total for that mechanism at the top of the robot, and then there are the rollers (what are they for, why are there two of them?), but otherwise almost all of the robot’s mechanisms, motors, etc. are pretty low to the ground. The robot will pretty clearly come in underweight, allowing for ballast to be placed in the drivetrain near the end of build season.
I agree that this game is very similar to 2009 in terms of how fuel should be handled by any team.
Without giving everything away, this robot’s fuel manipulation prioritizes volume over scoring directly. At lower levels of play, this robot can cycle gears and hang, with some low goal action whenever the robot gets the chance to score a point or two. At higher levels, this robot could grow into a great assisting robot, helping top tier shooters with fuel acquisition.
Pneumatics would definitely be an option for powering the elevator that would be robust and repeatable. However, this team doesn’t have any other pneumatic needs on the robot, and the team has a strong software group as well as a history with chain driven single stage elevators (2015). So a smaller, lighter version of the 2015 elevator was an obvious choice.
The floor raises and lowers primarily because it nearly doubles the robot’s ball capacity over a more conventional belt-driven ball loader thing. The floor also needs to be at a few different heights for the various outtake functions the robot can do.
I think the reason this rubbed people the wrong way was not attempting to point out an issue, but the tone of the message, specifically how absolutely certain you are of the issue. The way it’s phrased gives off the impression that you’re certain the team hadn’t thought of this issue or planned anything to deal with it.
Contrast it to the message posted directly above you, which is saying exactly the same thing but in a much nicer tone. By phrasing the concern as a question, it invites the team to respond with their plans to lower the CG of the robot. If the team truly didn’t plan for this, they get the information needed to know it’s an issue, and if the team did plan for this, they’re able to respond with their plans for doing so.