Our team just received the shipment for the controls for this year’s robot competition. We noticed that, after assembling all the sections needed for controlling the robot (not the driver’s board) onto a test-board, we noticed that the new controls system is considerably heavier than its predecessor. My question is did FIRST change the weight limit for the robots in this year’s competition because of the fact that the new controls system is heavier than the old controls system?
Thanks-
Skip
We don’t know yet. Wait until January.
This is an interesting question.
Obviously we don’t know yet,
but think about it though. Wouldn’t it be like FIRST to keep the weight limit the same or about the same just so that we would face a greater challenge this year?
It’ll be interesting.
At least we dont need spikes for the solenoids anymore!!!
AFAIK, OSHA Safety regulations limit the weight to be lifted by two people to 150 lbs, approximately the weight of an FRC robot with bumpers and battery attached.
If FIRST were to raise the weight limit, there would either have to be a lighter solution for either battery or bumpers, or teams would need to start carrying the robots with three members of their drive teams.
Consider it just another engineering challenge
Does anyone have an exact OSHA rule to quote? Upon searching the OSHA website I found the following:
http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=INTERPRETATIONS&p_id=24876
Question: Is there a policy or guide which states the maximum weight a person may lift?
Reply: OSHA does not have a standard which sets limits on how much a person may lift or carry. However, a sister agency, the National Institute for Occupational Safety and Health (NIOSH), has developed a mathematical model which helps predict the risk of injury based on the weight being lifted and accounts for many confounding factors. The model is based on previous medical research into the compressive forces needed to cause damage to bones and ligaments of the back.
Doesn’t look like there’s strict rules, just recommendations by NIOSH NOT OSHA.
A little further investigation and you will find that the limit is set by weight, and number of times lifted during a day. The 150 lb limit is stretching it but is within the guidlines as I remember. The MK batteries are a slight bit lighter than the Yuasa from earlier competitions. Still 120 (robot) + 13.82 (battery) + 15 (bumpers)=148.82 lb. I am hoping the GDC will allow lighter alternative interconnect cables for all the hardware of the control system though.
maybe they are planning the game around this new found extra weight. could be that it will require everyone to downsize a bit to find ways to be quick and able to fit in small spaces
Is there a solution? Are there lighter cables to be had/bought? Would the GDC consider allowing us teams to cut the cable length? (assuming the team has the proper expertise of putting on a new cable end).
Personnally-I doubt there would be allowances made.
Heck FIRST could even reduce the weight allowed and make a new design challenge for us all.
Just like everything else you never know what they may have up their collective sleeves.
I thought they were going with LabView because the program is lighter and compensates for the electronics…
After literally running with a 135lb robot in tow through the Atlanta tunnel to get to our match right after lunch on Friday (and missing lunch too :(), I am an advocate for reducing the maximum allowed robot weight. At competitions like Philadelphia '08 where there are only 40 robots and each team has 11 qualifications, there is potential to have to carry the robot on and off the field up to 13 times in a 6 hour period on Saturday.
We could return to something like the tiered weight system again, where 6’ tall robots may only be 100lbs, 5’ @ 110, and 4’ @ 120, or a reduced starting footprint tiered system. This means that bulkier bots have to be lighter so they’re easier to handle off the field.
Is there a solution? Are there lighter cables to be had/bought? Would the GDC consider allowing us teams to cut the cable length? (assuming the team has the proper expertise of putting on a new cable end).
Personnally-I doubt there would be allowances made.
There is aluminum wiring available, but specifically banned by the rules for safety reasons. It tends to start fires if too much current is drawn.
It is perfectly fine, electrically, to replace the bulky 37-pin cable to the Digital Sidecar with a lighter and shorter ribbon cable. That’s not an insignificant weight savings. However, we won’t know until the rules are published whether or not it will be legal to do so.
Dana,
Alan (above) is correct, short, custom, ribbon cables can significantly lighten the load. You may also not need all connections within a 37 pin cable and that would allow a further reduction in the weight. Just by shedding the bulky connector housing and hardware, I would guess you could loose several ounces. Packing all the bulk of the control system (fully decked out) into the robot is going to be a challenge as well. The RF rules for the wireless port will be similar for past radios. Mount the unit so that it is not buried down inside the frame where it’s output is shielded by metal components and handle all cabling with care. i.e. no sharp bends, pinch points, etc. and secure the case and all wiring to the robot frame.
Look, FIRST could make the weight limit 200 pounds and teams would still be overweight. The weight limit is a game challenge, just go with it. Now, there are plenty of strategies for weight reduction if you search about a little bit.
Personally, I don’t think the weight limit will change.
just my $.02, Vivek
At least one of those connections is a safety signal, necessary in order to ensure that the outputs can be shut off when the robot is disabled. I strongly suggest that teams not try to shave off fractions of an ounce by leaving out “unnecessary” wires between the NI 9403 and the Digital Sidecar.
Dear Santa,
Can you please drop the mandatory bumpers and instead give us 10 extra pounds to work with?
We’ll leave out extra cookies on Christmas Eve.
Thanks!
P.S. You might want to rethink giving coal to the kids on the naughty list. With the going price per ton nowadays, they might actually start a very profitable enterprise by all coordinating to sandbag their name onto the naughty list and profiting from all the free coal. You should switch to something non-flammable, like basalt.
Nooo! I love the bumpers. This was the first year we didn’t have our team-sew-er (whom we affectionately named Betsy Ross) sewing on the bumpers inbetween matches because of other teams sharp frames.