Paddle Wheel Task

[losjackal]

I believe part of the confusion is stemming from the fact that mattravn and I just want to use a single pulley to redirect the force. N = 1 so there is no mechanical advantage towards lifting the mass. If the spirit of the last task is all about how much mass can be lifted, I would think a single pulley would be acceptable. But if it's also about designing the box so the axle is high enough to lift 10cm/20cm/30cm, then clearly a pulley would violate that.

[mnstrviola]

I believe part of the confusion is stemming from the fact that mattravn and I just want to use a single pulley to redirect the force. N = 1 so there is no mechanical advantage towards lifting the mass. If the spirit of the last task is all about how much mass can be lifted, I would think a single pulley would be acceptable. But if it's also about designing the box so the axle is high enough to lift 10cm/20cm/30cm, then clearly a pulley would violate that.

This is exactly what I had in mind for our device too. It wasn't clear to me: has anyone submitted an official clarification for this yet?

[Flavorflav]

I'd like to weigh in on the side of matttravn here. In NY, we have the rule that clarifications and FAQs issued more than two weeks before a tournament are binding, while those issued later are not. I will be judging this event in about a month, so unless a FAQ is published on this issue in the next two weeks I will feel compelled to allow pulleys and gearing after the mass, since as mattravn notes there is nothing in 4.m.3 which prohibits them. This means that any team which has asked for and received a reply from SOINC will be at a competitive disadvantage if they abide by your answer to their question. It would be a shame for teams to suffer because they tried to follow the rules, IMO.

I'm admittedly biased right now, but I really don't get the confusion about this rule. 4.m.3 clearly states how the device should operate and neither 4.m.3 nor 4.m.5 mention anything about pulleys being permissible, in fact 4.m.5 seems to indicate the exact opposite (of course, in my personal opinion). I also don't think it's a competitive disadvantage, as you can certainly lift a tremendous amount of weight without using a pulley (we theorized over the summer that 40kg might be possible, albeit highly unlikely) and in fact may be at a disadvantage because of the extra amount of time it will take to lift the mass and the increased difficulty of lifting it 10/20/30cm. However, I would suggest everyone who still has some level of confusion to submit official clarifications about it.

General rule 2. If pulleys were out until specifically permitted, 4.m.2 would be unnecessary.

IMO the benefit of the pulley has nothing to do with mass and everything to do with space. I'm not coaching B and I only found out I was running this event a week ago or so, but when I read the rules my first thought was that this task was going to require a fair amount of space. If the mass must be lifted directly, then you have fewer options about where to put the reservoir-wheel-mass complex and its dimensions are less manipulable. With a simple fixed pulley, your options increase.

[chalker7]

General rule 2. If pulleys were out until specifically permitted, 4.m.2 would be unnecessary.

IMO the benefit of the pulley has nothing to do with mass and everything to do with space. I'm not coaching B and I only found out I was running this event a week ago or so, but when I read the rules my first thought was that this task was going to require a fair amount of space. If the mass must be lifted directly, then you have fewer options about where to put the reservoir-wheel-mass complex and its dimensions are less manipulable. With a simple fixed pulley, your options increase.

Right, but general rule #2 also includes the spirit of the problem clause. Do you think attaching counterweights to the axle, spring loading the axle or even attaching a small electric motor to the axle would be legal? None of them are explicitly prohibited by rule 4.m since everyone seems to think 4.m.2 only applies to the paddlewheel/axle. If you think those are different from a pulley, how so? If they are not different from a pulley, good luck getting a judge to allow any of the components in your device.

[Flavorflav]

General rule 2. If pulleys were out until specifically permitted, 4.m.2 would be unnecessary.

IMO the benefit of the pulley has nothing to do with mass and everything to do with space. I'm not coaching B and I only found out I was running this event a week ago or so, but when I read the rules my first thought was that this task was going to require a fair amount of space. If the mass must be lifted directly, then you have fewer options about where to put the reservoir-wheel-mass complex and its dimensions are less manipulable. With a simple fixed pulley, your options increase.

Right, but general rule #2 also includes the spirit of the problem clause. Do you think attaching counterweights to the axle, spring loading the axle or even attaching a small electric motor to the axle would be legal? None of them are explicitly prohibited by rule 4.m since everyone seems to think 4.m.2 only applies to the paddlewheel/axle. If you think those are different from a pulley, how so? If they are not different from a pulley, good luck getting a judge to allow any of the components in your device.

I honestly don't see how most of your examples are relevant to the question at hand, since all of them would explicitly violate 4.m.1. I also do not see how a single fixed pulley at the top of the device violates the spirit of the problem, since it adds nothing to the force except a change in direction.
Also, FYI, I don't have a device. As I noted above, I will be judging next month.

[chalker7]

I honestly don't see how most of your examples are relevant to the question at hand, since all of them would explicitly violate 4.m.1. I also do not see how a single fixed pulley at the top of the device violates the spirit of the problem, since it adds nothing to the force except a change in direction.

That's not true, 4.m.1 only mentions the paddle wheel and I'm saying those would be connected to the axle. I obviously don't think those items are legal to use, but I am trying to extend the same logic that everyone is using to say pulleys would be legal.

[mattravn]

Hey all,

I'll weigh in once more. I did ask for an official clarification on if the items excluded in part 2 apply to the entire task or specifically to the part of the task listed in part 2. I will post and we will see if an official clarification is issued.

To the other discussion at hand, I thought that the general interpretation of the rules for Mission Possible was that unless an item or object was specifically excluded by the stated task or general rules that it is generally allowed to use whatever parts are desired to accomplish the task. That is that prohibited items must be excluded and not that allowed parts must be listed. Pointing again to the way in which the task sheet is written, the exclusion of pulleys is listed specifically within part 2 of the task which discusses the connection of the wheel to the axle and not as part of the general 4m description.

This might not have been the initial intent of the task according to the committee that put together the task sheet, so I still think an official clarification would be needed to know if pulleys are excluded from all parts of task 4m or if it applies to part 2.

Cheers and best of luck finishing up before regionals

[chalker7]

To the other discussion at hand, I thought that the general interpretation of the rules for Mission Possible was that unless an item or object was specifically excluded by the stated task or general rules that it is generally allowed to use whatever parts are desired to accomplish the task. That is that prohibited items must be excluded and not that allowed parts must be listed. Pointing again to the way in which the task sheet is written, the exclusion of pulleys is listed specifically within part 2 of the task which discusses the connection of the wheel to the axle and not as part of the general 4m description.

This is true and not only applicable to Mission Possible, it applies to all events. Specifically it comes from "General Rule #2," which is published both in your rule book and online here: http://soinc.org/ethics_rules The issue at hand isn't whether it is written into the rules, it is obvious that it is not. The issue is whether using a pulley to assist or reroute the lifting of the mass for the final task violates the "spirit of the problem."

Asking about it in the clarifications is the correct way to do this and it will be resolved through that route, but having a healthy discussion about the wording of rules is always good.

[Flavorflav]

I honestly don't see how most of your examples are relevant to the question at hand, since all of them would explicitly violate 4.m.1. I also do not see how a single fixed pulley at the top of the device violates the spirit of the problem, since it adds nothing to the force except a change in direction.

That's not true, 4.m.1 only mentions the paddle wheel and I'm saying those would be connected to the axle. I obviously don't think those items are legal to use, but I am trying to extend the same logic that everyone is using to say pulleys would be legal.

But if the paddle wheel is directly attached to the axle, then anything turning the axle would supply a force turning the wheel in violation of 4.m.1. If the wheel is not directly attached to the axle, then there is a violation of 4.m.2. Passing the string through a pulley before attaching the mass violates neither, and since the string still lifts the mass it also satisfies 4.m.3.

[chalker]

I think we can end this particular conversation now: http://soinc.org/node/896