There’s a longstanding rule of thumb in FRC - never put anything outside the frame perimeter unless you’re prepared for it taking serious physical abuse. I honestly can’t think of a single robot part I’d rather NOT take serious physical abuse than the battery. Most parts would just be money and time, this one would be a real safety issue.
As an RI, if I couldn’t find a way to fail your battery-out-of-frame-perimeter-robot inspection (and I’d give it my all), I’d call in the LRI. If I were LRI and couldn’t find a way to fail your battery-out-of-frame-perimeter-robot inspection, I’d call Al or Chuck. And if I were one of the head LRIs, I’d rather err on the side of safety than permission, and my experience with both of them is that they feel the same way - even when I disagree with them.
Honestly, I was hoping that Q68 would result in a team update requiring the battery stay inside the FRAME PERIMETER.
If you’re only doing this whilst climbing, have a real solid hold on the battery and cables protected, willing to accept the losses involved in a long battery cable, and the climber works bang on almost every time, I’d go for it. SLAs can take much more of a beating than most people will lead you to believe, especially the 18ah form factor FRC uses. Add a sheet metal enclosure and nobody can really tell you no unless they have some weird, twisted desire to ruin your day (see above).
We’re already chill with robots climbing 6’ or so in the air and falling onto effectively concrete while containing the same battery in rigid mounting. I fail to see how this is significantly different, unless we’ve got people zip tying cordless drills to their intakes like its battlebots in 1999.
It’s the fact than a volunteer and mentor in our program would be out to “get” a team because they did something perceived as unsafe or incorrect. We’re here to educate and inspire. Admitting on the internet that you’d “find a way” to fail a team even if they aren’t breaking any rules does the opposite.
Also, here’s a battery that was punctured with a soldering iron at an event I volunteered at in 2017. I am still alive, for the record.
I’ve unintentionally drilled multiple 3/16" holes into an SLA in the robot and then won an eliminations match right after with that battery…
Should you do that? No, absolutely not.
An SLA battery exposed during the endgame is no more dangerous than the fairly common routine of mounting one vertically above the bumpers, where it could easily be hit by an intake at a combined 30+ fps.
I’d like to point out that this configuration MAY violate not one, but THREE rules. Excluding headlines and blue boxes:
G101: ROBOTS whose operation or design is dangerous or unsafe are not permitted.
R202: Protrusions from the ROBOT and exposed surfaces on the ROBOT shall not pose hazards to the ARENA elements (including CARGO) or people.
R203: ROBOT parts shall not be made from hazardous materials, be unsafe, cause an unsafe condition, or interfere with the operation of other ROBOTS.
Note that I specifically said “MAY”. A lot will depend on the implementation. And a wise designer will keep those rules in mind.
Two additional rules notes:
R605, despite what its headline says, doesn’t apply. This IS the main, one and only one, SLA battery powering the robot.
R606 requires the battery secured so that it does not dislodge. Your line of discussion with the RI/LRI on this one is simple: Within its holder, the battery is not moving. The holder does not move in an uncontrolled manner. Therefore, the rule is satisfied.
If the design of this sort of thing violates any one of those (and you’ll note that the blue boxes are not exhaustive lists of issues), then you can expect disablement and/or not being allowed on the field and/or not passing inspection. IF. See above comment about designing within the rules.
Now, I don’t agree with going out of the way to fail a team. If I were inspecting, I would be looking for something like Troy described: enclosure, good cable management (both for the team using it and in case of some other robot snagging), and a secure battery. If a team were unable or unwilling to make enough modifications to whatever they had to satisfy that, THEN and ONLY then would I have to tell them that I could not pass them as-is, and they’d need to rework it to not extend–and by then the LRI is involved if they weren’t involved at first. Whether the LRI involves the CRIs, above my pay grade.
Then you say it violates said rules which is an easy case to make. You don’t say you’ll find a way to fail them even if it takes running the issue up multiple levels. Bad post and frankly wouldn’t want an RI with that type of logic going through their thoughts.
Going back to the original post, I wanna recognize @BrooklynTony198 for this really innovative idea.
A lot of long time veterans of this program would see this an obvious solution to consider, but it still showcases some really creative, out-of-the-box problem solving when a student without prior exposure to the concept is able to come up with this on their own.
Ignore the haters, Bärin. Continue looking for creative solutions like this with every problem you approach. You’re already showing promise as a great engineer. Keep it up!
*Don’t expect to gain by doing others harm. Strategies clearly aimed at forcing the opponent Alliance to violate a rule are not in the spirit of FIRST Robotics Competition and not allowed. Rule violations forced in this manner will not result in an assignment of a penalty to the targeted Alliance.
What rule would it cause other teams to break? Well, if a metal piece of an opposing robot ended up touching one of the battery terminals, they would briefly be in violation of R611:
*The Robot frame is not a wire. All wiring and electrical devices shall be electrically isolated from the Robot frame. The Robot frame must not be used to carry electrical current.
Which would cause them to fail inspection in the middle of a match, which would normally get their alliance a red card under I102 were it not for G201.
Actually, if that were to happen, the robot with this device would violate R607, and the inspector who let that one through would be having a minor discussion with the LRI, right after the LRI had a minor discussion with the offending team (along the lines of “you have electrical tape, right? Good, now use it on those battery terminals and I’ll be back in 15 minutes.”).
This is some really good thinking outside of the box and frame perimeter
I am going to keep my comments purely technical in nature.
As @troy_dietz pointed out, the battery cables will have to be very long and will lead to quite a bit of voltage drop when your robot pulls a lot of current. It will be easier for your robot to suffer from brown-outs.
It may be better to use a “slide-out tray” like the team asking the question in the Q&A that @MikLast linked. This would keep the center of gravity low at all times. Having the battery so high before you hang, which is most of the match, will tend to make your robot “tippy” and possibly harder to drive smoothly.
Is it possible to move a different part of the robot (that is not used while hanging) to get the same effect? Is there any reason you do not install the shooter higher? It could be the part that pivots out to change your center of gravity. It may be good to add some protective covers if you do this. You should not be facing defense while hanging but enthusiastic and/or unskilled drivers of other teams on your alliance can damage to your robot during the hang.
That’s not at all what I meant. I am not out to get a team, I’m promoting safety. By “Find a way”, I meant finding a rule that had been violated because I saw an unsafe condition. And if I couldn’t find such a rule when I saw something clearly unsafe, I’d kick it “upstairs” hoping they could.
I take the role of robot inspector seriously - enforce the rules, make the competition safe, and advise teams on things they can do better*. The very first robot inspection I signed was for 3937 at Arkansas/Rock City in 2019. I passed them, but gave the advice that they should move their main breaker so that a hatch panel wasn’t likely to fall on it. Unbeknownst to me until after the event, @Breakaway3937 told them to move that breaker based on my advice. They didn’t. Somewhere during the event, a hatch panel fell on it, presumably with lost-match consequences. I try not to think about the in-team consequences. Unsuccessfully.
I totally want to help teams, but not by compromising safety.
Let me further note that OP admitted his idea was “sketchy”, and that his battery extended outside the frame perimeter had ho protection at all. If it had been wrapped in angles, my thoughts on this might be different.
* It’s not officially in the job description, but that’s actually my favorite part!