I finally got around to tidying up and uploading the main breaker shroud that I designed during DCMP this year!
Here is the prototype mounted on 2412’s robot Crane:
I modified the design slightly to allow both cables to come out the sides, and to improve printing without support. I also made versions for all 3 possible wire orientations:
Check it out and download here: TheNiftyBot.com - Breaker Shroud
I really, REALLY like this design!! Particularly how it covers the cable bolts that always seem to lose their little rubber covers. Very nice!!
We designed this one below years ago and have been using it. It snaps over the edge of the Breaker and makes the leads finger safe. We always print it in red so it draws the eye and makes it easier to spot the breaker location.
Covering the screw terminals means they can’t be as easily inspected. We had one nut come loose last weekend (not sure why - it’s been through a full season without issue) and we lost two matches to early brownouts before we discovered the problem. The nuts will be added to our regular inspection checklist.
This looks like the reset button can still get hit by something outside your robot, which could power you off in a bad collision… so what’s this doing besides making the breaker nuts harder to inspect?
Like I said it makes the power leads fingersafe. Prior to that, like a lot of teams we are exposed to, we simply taped the leads and nuts.
We tear off the rubber cap and replace the star nuts with Locking nuts and have never had a lead come loose.
Additionally we have never experienced a collision that would have a robot encroaching our frame perimeter far enough to get close to the Breaker. I suspect of you are in a collision that bad, you are going to experience mechanical failure. A little bit of PLA won’t stop an errant robot arm from still hitting the switch.
I think traditionally it has been to prevent game pieces from disabling robots moreso than collisions. I think the frisbee year was one that had some unprotected breakers more often getting hit by falling game pieces.
I’m sure that happens more often than the robot collisions. We typically design so that a game piece is not able to get in near the breaker. Obviously anything is possible and so far, knock on wood, we haven’t had a problem.
You’ve gotten very lucky then. I’ve had breakers turned off by game pieces and by opposing robots. Putting a shroud around the breaker reset is pretty common practice these days. It’s basically a zero cost risk-reduction if you’re already covering your breaker.
Thanks! I designed it in response to years of inspectors saying that the rubber covers aren’t good enough and should be ripped off and replaced with ugly electrical tape. Years ago I designed some 3D printed nyloc nut caps that covered the terminals, but I wanted an all-in-one solution that also shields the off switch.
From what I’ve observed most inspectors just need to wiggle the cable to know if it is tight. I also highly recommend using Nord-lock washers and nylocs for a maintenance free vibration-proof connection.
Nice design! That looks great for spots where the breaker is already protected. The biggest con I have found with my design is that the connections must be made before it is bolted down. I was trying to come up with a way to change that and I was thinking that a clip on version might be the way to go. I might copy that feature for V2.
This. I recommend that as well. And yes, as an inspector, I usually grab those leads and give them a good side-to-side to see if they are tight. That’s the LAST reason I want to cause a team to lose a match!
this is important
Checking to make sure these are tight is a regular maintenance step on our checklist.
Nord locks are wonderful but they aren’t perfect
I believe Brendan was more refering to inspections done by teams inbetween matches to ensure their robot is functioning properly (ie, ensure your breaker nuts havent loosened off) rather than during official robot inspection with robot inspectors. And furthermore, if they had loosened, how easy does this cover make fixing that?
Just some questions to provoke thought on how you could possibly improve on what is already a cool and useful design.
This is sufficient to determine if a bolted connection is sufficiently tight.
You’re using an Optifuse. Those are dangerous junk and I threw the couple we had in the trash. I suggest you do the same
The info about those came out well after the robot in the picture was built. I don’t believe we have any of those left. Except on our robots, we have every robot together except for the first 2 years.
Would it be possible for you to put this on Printables? It just makes it easier to share.
For anyone reading along and not knowing what this is about, see this thread for relevant info.
First match I ever played with @George1902 (smoky '22), he told me to put a ball on the corner of our chassis so it would roll off in auto. I wasn’t thinking and put it directly onto our breaker. Match started, arm came down, robot immediately turned itself off.
Lesson learned.
We (2102) took an intake to a breaker at 2018CADA. If you’re ever at an event and need to improv a breaker shield quickly: the inner cardboard tube of a roll of duct tape fits nicely around a breaker and the button will sit a little sub-flush.
