How will the inspection of the robot’s volume with the bumper on be inspected?
Will they drop a huge plexy sizing cube over the robot? Or will it be measure with a tape measure.
Here is our situation…
With our bumpers on we are about 1/8 to 1/4" wider than required. If an inspector lowers a sizing cube over the robot and with a very little push our robot will fit in. (We tried) This is due to some bolt heads we have sticking out of the frame and as I understand screw heads do not count toward the size of the robot frame.
We are considering cutting our robot in half and taking out this distance with the frame and re-welding. But that will be a time consuming ordeal…
Any advice…
Note: This is a good learning lesson for our team as to not push the exact sizing limits.
The robot will be dunked in a tank of water and measured by displacement actually I think it will be done by tape measure. I would check the manual though.
The allowance for bolt heads only applies to the frame perimeter, NOT the volume limitation.
If it’s just some bolt heads behind the bumpers, can you pocket the bumpers where the bolt heads are to allow it to recess?
How tight is your fabric over the noodles? You can’t compress the noodles with tape or something similar but you can make sure the fabric is tight over them
Also are the bolts pushing the bumpers out from your frame and causing this problem? If so, you can drill or notch out clearance pockets
Are there any rules to the compression of the pool noodles with the fabric. If I compressed the noodles with the fabric no more than 1/4" would any eye brows be raised? In your opinion… I appreciate your time
Bumpers thickness the rules read that they need to be 3/4 inch plywood and 2.5 inch pool noodles meaning the bumpers should be 3.25 inch. However the rules then go onto say “Noodle compression as a result of smoothing BUMPER fabric is not considered deformed. Any compression beyond that , e.g. for the purposes of flattening the noodle, is deformation and a violation of R29-”. Since this is very arbitrary on the thickness could we please get a ruling on minimum thickness of bumpers
No, no specific minimum will be provided beyond the rules you have already cited.
yes, 1/4" would raise some eyebrows. there is no specific spec, though. if the noodles are obviously out of round, it’s not going to fly. see Q291
Things you can do to have the thinnest legal bumpers that I know of.
Pocket the back of the bumper to fit over your minor protrusions.
buy the thinnest wood you can find that is sold as 3/4". most 3/4" plywood is actually 23/32".
buy the thinnest pool noodle shape you can that is sold as 2.5". I suspect (but have not tested) that petal or hex noodles that are 2.5" diameter nominally are not that thickness at every angle.
Don’t use the optional clamping metal.
Use embedded mounting hardware (like T-nuts)
all of that together might save you 1/8" or so on each side.
If a sizing cube of some sort were used, it would have to be rigid and inflexible, and capable of remaining square over 9 weeks of travel and competition use (something the old sizing boxes had difficulty with).
If a tape measure were used, how would you know if the robot was square? A parallelogram may measure from side to side just fine, but still not fit within the volume requirements.
You stated pretty clearly:
With our bumpers on we are about 1/8 to 1/4" wider than required.
Regardless of the method used to measure the robot, you clearly know you are illegal. Some great suggestions have been provided here for helping to shave off that extra little bit without making major modifications.
All of that said, there are some opportunities coming up for you guys over the next week to get some in-person help! The CMNRH is hosting an event TONIGHT in Becker to provide exactly that sort of assistance to teams. I’ll be there, and your drive will be a little shorter than mine, so no excuses! There are also a number of week-0 events coming up in a week, and we’re planning on having inspectors or LRI’s at each of them! Please let us help you in person - I would love to help you avoid making any drastic changes if at all possible, and all of your LRI’s in the state would like to help you ensure you fit within the volume constraint before you show up!
If you want specific criteria on how your robot will be inspected, then this is basically a cheat-sheet. FIRST released the inspection sheets that judges will use to inspect your robot. If your robot passes the guidelines in this sheet, then it should be fine being that this is the inspection sheet released on the FIRST website.
The Checklist simply states that you ARE in compliance. It does not address HOW you are in compliance, as far as volume checks. That being said, the inspectors are very good at coming up with ways to check robots. I would suspect some variant of the “taped box on floor next to wall with long-edged square” if some sort of sizing box is not available. It’s a pretty reliable method if you know how to set it up.
OP, you’ve learned a lesson that many a team has learned before you, the hard way. Back when the sizing box was used to check robot sizes, you had two options: Fit your entire robot inside, or figure out how to make your robot fit inside. Invariably, someone would forget (or not know) to build at least .5" undersized to account for the bolt heads–many teams would build 27"x37"x59" robots if the box was 28"x38"x60". The inevitable result was some combination of sawzall, welder, grinder, or panicked hardware changes.
*Judges (blue polo shirts) do not inspect your robot for rules compliance. That’s the Inspectors’ (yellow hats) job.
We have went back and measured bumpers going back many years and just about everyone of our bumpers are 3" from the wood to the front of the fabric.
The bumper assemble rules are the same as last year. Have we just always been wrong and got “away” with it?
I will make an educated guess that a 3 inch thick bumper will pass inspections; just like it did last year at the Bayou Regional, Rocket City Regional, and the Hopper Division at St Louis.
In my experience, most pool noodles that are sold as 2.5" are actually closer to 2.25", which explains your old bumpers measuring in at 3". It’s not a high precision COTS piece. Also, there’s a certain amount of compression the noodles will naturally undergo over time as they get bashed into robots and walls over and over.
I fully expect 3 inch thick bumpers made from nominal 2.5" noodles that are actually 2.25" diameter and 3/4" thick plywood pressed flush against the frame perimeter and wrapped with cordura tight enough to pass as “smoothing fabric” will pass inspection again. That said, 3946 has built our chassis based on a 3.5" thick bumper as a safety factor.
actually I think it will be done by tape measure. I would check the manual though.