Who want a little more weight for there robot instead of 130lbs? I mean at the last couple days you have more weight then you need or should have. I think they should add 5 more pound to the weight limit. with this 5 pounds you could open the possibles with 5 more pounds. What could you add to your robot that is 5 pounds that could really help you? so who likes the idea.
honestly… i think it all depends on what the game is, and how many diffrent complexitys it has next year… but i also think it depends on how many motors there are, and thier wieghts if they are heavier than this year…
This has been discussed numerous times before. While nearly everyone except who’s lifting it weould enjoy the extra weight-space, the problem is if the limit was 135 lb, why not increase it to 140, aw heck, how about making it 145 lb, and so on and so forth. I think the goal of sticking with the 130 lb limit consistently, is seeing how much you can pack within that restriction, rather than how much you can expand with extra weight. The challenge is not how many ideas can you fit on your robot, it is how can you even fit the ideas you have.
It need not be increased. It is part of the design challenge.
The whole point of making the weight limit to 130 lbs is because teams need challenge. This is one way a team can prove how good they are mechanically and how complex can they make their robot… 
p.s - i was a little late to post this one… Zach P. beat me to it…
If the weight limit is raised 5 pounds, people will find 10 pounds more crap to put on their robot.
No matter what the weight limit is, a large number of teams will ALWAYS have trouble making it
$0.02 Cory
I don’t think I’d like carrying a 140 lb. robot on the field.
OR
have it slip and fall on my feet, or something.
From a designing and robot performance standpoint, this is an excellent suggestion. I could do a lot with some extra pounds to play with. But otherwise, I think its good as a challenge and also for safety reasons.
I second the carrying that weight, its bad enough to work with 130 pounds.
Get steel toed shoes, they make tennis-shoes made with steel toes, I have a pair, sure they’re a few pounds heavier but its protected my feet MANY times.
The weight limit is just another part of the challenge along with everything else.
I personally would like to see 120 -125 lbs without the battery. One of the problems is that battery weight varies as much as a pound from 1 battery to another.
Just really seconding what has been mentioned previously, the weight is all part of the challenge. It is another design obstacle that you must overcome. In real engineering situations, there will be limitations that FIRST also employs, including suppliers, prices, weight, size, etc.
I second that, I’ve already thrown my back out carrying around the robot as is, 130 lbs. is definitely enough. 
I totally agree. We were like 129.99999999999(repeatingHAHA) and we did weight reduction before we added things, such as our goal grabber we added at MWR.(I think it was MWR.) It is something that is a challenge outside the game itself. We all need to just deal with it. (meant nicely)
I also agree with that…I mean come on if the game has like 10 different things to do there will be teams that want to do it all. And if there are more motors that would take away weight to use for stuff to play the game. If the game doesn’t really require that much “extra” parts, but more motors I think it should stay the same, just to make things more challenging. :rolleyes:
-Kyle
i see what you mean now and i think that they should stick with the weight limit of 130 because that makes you think more then just we can do it we have the extra weight. so they should keep the weight limit the same.
I guess I’d like to throw in a few comments on this…
When you look at the weight of a FIRST robot, much of the weight is non-negotiable. Things like the drive motors, battery, chain, wheels, controller, speed controllers and wiring, (and everything the electronics mount to) are all very steadfast items. Even a drive frame, in whatever form, is something that every machine must have. I think that I could conservatively say that 40 lbs of a robot is absolutely non negotiable.
With that said, adding another 10 lbs would really be like adding another 11% to your robots’ weight.
And when you really think about it, there aren’t a lot of teams that are at 160 lbs (after their rookie year) who are trying to cut down to 130… they’re at 136 or so trying to make it.
I think another 10 lbs would make the game a lot easier for rookie teams. I also think that the powerhouse teams would dominate that 10lbs much more than any rookie team ever could.
And hence I don’t like the idea.
Matt
You must also consider the shipping cost. The heavier the robot is the heavier the crate is the heavier the shipping bill is.
I’m down with the above arguements, but I see two problems.
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I do recall reading (although I can’t say this officially) that FIRST robots as we know and love today are sized so that two average people can lift it and carry them through a normal doorway. Adding another ten pounds would start to make it harder to carry.
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Adding weight starts us down a slippery slope. If in 2005 we get more weight, everyone’ll jump for joy. Then we’ll max out that extra ten pounds or so. Then we’ll start complaining for more weight, since we got it last year. This, in turn, contributes to problem number one.
Just my thought process.
Cory is exactly right. If teams got 5 more pounds, then they’d just make things more robust and add more to it and in turn be 5 pounds over that limit. I’m sure there would be some teams who would act blind to the new limit and be over a bit and be ok, but there are many who would not and would want to use every single pound available. The weight problems would stay about the same, in my opinion. I believe it should stay at 130.
There are several important concerns that have been brought up here.
- The 130 weight is a design constraint, part of the challenge.
- Safety - 130 divided by two persons 65 each that is still a lot of weight if you fall or have a distance to go. A Major safety concern.
- Next year I believe that the battery will not be included in the weight and there may be a gain if say FIRST decides that 120 lbs is the weight without the battery. A net gain of about 4 pounds or more.
No matter what the limit is set at, I believe that there will always be the “pushing of the limit” to build the best durable machine.
Teams that are consistently designing and end up with weight problems need to look at their design process and make corrections in “Weight Management”.
For some strange reason we’ve never built a robot more than 135 pounds (prior to seriously considering weight reduction). Usually the kit material puts you in a standard range for extra robot material to wind up around 130-135 pounds, it’s some kind of natural law. Anyhow, I have faithfully thrown my back out every year carrying these things on and off playing fields. But I still would like to see it go to 135. It has been our magic number.
This year we were really on the ball with weight reduction in the design (120 lbs) but, at the comps we had to beef her up to take the punishment everyone was dishing out, and wound up 131 minus shavings to 129.999.
The thing is, years past without trying too hard we got around 135, then this year we went overboard and got 120. It’s not a big difference. Experience has taught me how to do a lot with 5 lbs - true. But inexperience and 5 extra pounds would make making robots (which is extremely stressful) much easier.
It would be good to see a weight study showing what the kit material puts you at for a typical bot configuration. Then see what kind of weight/mass ratio is left over. I bet it’s not much.
Some tips for Weight Management
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“budget” no more than 90% of the weight limit. ie if the limit is 130 lbs then the total estimated weight of all systems should be no more than 117 lbs.
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Identify and quantify non-negotiable weight first. So know how much your controller, breakers, lights etc. weigh. Subtract this weight from the budget.
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what is left is available for adding non-essential systems. Note: depending on the game, a drive system may be negotiable.
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Assign budgets for all subsystems based on criticality. A really critical system should have a bigger budget than a nice-to have.
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Do a weight estimate for any proposed subsystem BEFORE you build it. Hint we’ve found that Inventor is pretty good at weight estimates if you put in the correct material data.
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Use your estimates to trade off between systems.
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Resist the temptation to say “I think I can get a couple of pounds out” and then use the lower number. Every item in your estimate should have documentation to back it up. If you think you can take weight out, fine. Prove it first, then change the number.
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Track the weight of each subsystem continually. If possible weigh each part before it goes onto the robot.
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Use a spreadsheet for your weight tracking. Constantly compare actual vs estimated weight. Beat on the designers of subsystems that are over weight to get the weight out. The spreadsheet can also be used to identify “heavy hitters”. Items that are extraordinarily heavy (and thus prime targets for speed holes) or items that use a lot of weight for minimal functionality.
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Assign a single person whose whole job is to make sure you meet weight. We call ours the “weight czar” a term that comes straight out of the aircraft biz. In fact, at the “bird factory” I work in, every program has a whole department dedicated to tracking the current estimated and actual weight of the aircraft. We wouldn’t do that if we didn’t think it was important, there too many other things we need to throw bodies at to waste them on something unimportant.
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Remember that nothing ever gets done within the budget. That’s why you only allowed 90% at the beginning, to account for unknowns and overruns. If that doesn’t work this year, then next year cut the budget to 85%
Chris is ABSOLUTELY correct. Regardless of what the numerical limit is, it would benefit us all to use these weight management ideas.
Here at Rolls Royce we also have several people dedicated to tracking the weight of our engines. Any change that is proposed for any flight engine is heavily scrutinized for weight impact. We pay a hefty financial penalty if our engines exceed contractual weight limits.