Paddle Wheel Task

[Dark Sabre]

Topic for discussion.

[hogger]

According to the rule, the paddle is attached to an axle that in turn attaches to a string that wraps around itself as the wheel turns. Does anyone think that the string can be hoisted up high and hung off an anchor before attaching to the mass? Would that be illegal and considered a pulley? Or maybe pulley is allowed at this point since rule (2) in part m only prohibits attaching pulley where the wheel connects to the axle.

[chalker]

According to the rule, the paddle is attached to an axle that in turn attaches to a string that wraps around itself as the wheel turns. Does anyone think that the string can be hoisted up high and hung off an anchor before attaching to the mass? Would that be illegal and considered a pulley? Or maybe pulley is allowed at this point since rule (2) in part m only prohibits attaching pulley where the wheel connects to the axle.

FYI, there have been numerous questions submitted to soinc.org about things like this. The general response is NO PULLEYS at all in the final task. Of course if you want an official response to your specific design, feel free to submit a clarification request on soinc.org

[rmp509]

According to the rule, the paddle is attached to an axle that in turn attaches to a string that wraps around itself as the wheel turns. Does anyone think that the string can be hoisted up high and hung off an anchor before attaching to the mass? Would that be illegal and considered a pulley? Or maybe pulley is allowed at this point since rule (2) in part m only prohibits attaching pulley where the wheel connects to the axle.

FYI, there have been numerous questions submitted to soinc.org about things like this. The general response is NO PULLEYS at all in the final task. Of course if you want an official response to your specific design, feel free to submit a clarification request on soinc.org

I have tried to submit some ideas but the response was "we cannot tell you if your ideas are allowed or not, you must submit a question concerning wording of the rules, not an opinion on an idea" plus it takes them 5-6 weeks to respond but its worth a try.

[chalker]

I have tried to submit some ideas but the response was "we cannot tell you if your ideas are allowed or not, you must submit a question concerning wording of the rules, not an opinion on an idea" plus it takes them 5-6 weeks to respond but its worth a try.

Maybe I should have worded my response a bit better. Yes, in general we don't give answers about the legality of specific designs. A big part of the reason for that is it's usually very hard to understand the design without seeing it actually implemented. What we do respond to though are more generic questions such as "can a pulley be used as part of the final task condition #3" (as I indicated we've already answered several questions like that with a NO).

Regarding the delays in responding, it's really hit or miss. Once a question is submitted, it sits in a queue until the clarification chair does an initial review an then send it out to several people such as the national event supervisor and appropriate committee chair. Then it sits in their email boxes until they get a chance to review it and suggest a response. Then the clarification chair compiles the responses, perhaps discusses it with the national leadership, before finally issuing the formal response. For simple, obvious things, this whole process can happen in a day or two. For more complicated matters that we might debate about internally it can easily take weeks or longer. For example, there is one series of questions right now related to Storm the Castle that has been sitting for 2 months because we can't come up with a good answer that won't confuse the situation more.

That said, please still submit questions, because regardless of the timing of the answer, we analyze the questions at the end of the year to help us make improvements / changes to the rules.

[bri2433]

Once you lift the mass to the required height can it go back down?

[foreverphysics]

Once you lift the mass to the required height can it go back down?

Yes, I believe so. I think timing stops once it reaches the required height. However, I would tell the proctors before running your device.
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[Kordo]

I have asked for a clarification on the final task asking if the mass being lifted can be pulled up a ramp instead of being lifted. It's been 3 weeks and I have not received a reply. At the invitational I went to many of the devices were using ramps and were being allowed but I am wary about letting my team use a ramp until I get a clarification. I was wondering what your view is on the subject?

[foreverphysics]

I have asked for a clarification on the final task asking if the mass being lifted can be pulled up a ramp instead of being lifted. It's been 3 weeks and I have not received a reply. At the invitational I went to many of the devices were using ramps and were being allowed but I am wary about letting my team use a ramp until I get a clarification. I was wondering what your view is on the subject?

It takes 5-6 weeks to get a clarification, on average (according to what I've heard). I would just stick with the old saying "Better to be safe than sorry" and not pull it up a ramp...because "pulling" is not "lifting". So I would say no, don't use a ramp.
Also, why ask me? Why not ask the Chalkers?

[chalker]

I have asked for a clarification on the final task asking if the mass being lifted can be pulled up a ramp instead of being lifted. It's been 3 weeks and I have not received a reply. At the invitational I went to many of the devices were using ramps and were being allowed but I am wary about letting my team use a ramp until I get a clarification. I was wondering what your view is on the subject?

It takes 5-6 weeks to get a clarification, on average (according to what I've heard). I would just stick with the old saying "Better to be safe than sorry" and not pull it up a ramp...because "pulling" is not "lifting". So I would say no, don't use a ramp.
Also, why ask me? Why not ask the Chalkers?

First, standard caveat that this is not the place for official clarifications. I'm sure the one you submitted is in the queue somewhere. That said, are you sure other teams were using a ramp for the FINAL task? Keep in mind there is also a SPECIAL task (4.l in the rules) that explicitly calls for pulling a mass up a ramp. I'd suspect a lot of the devices you saw were doing just that. That said, I'd also question what advantage if any using a ramp for the final task would have. The ramp would introduce friction to the system, meaning the paddle wheel would have to generate even more force than if it just lifted the mass freely.

That said, my unofficial view on the matter is that using a ramp for the final task is not within the spirit of the problem. We used the wording 'lift a mass', which is much different than if we'd said something like 'cause a mass to rise' or 'increase the height of a mass'.