Paddle Wheel Task

[Science-dad]

Good Morning All,

We just had our invitational and I was asked to help out judging along with a volunteer from another school. The question came up if this actually had to be a paddle wheelwith fixed blades or cups or could it be more of a ferris wheel with rotating cups. We did a quick check and could not find an answer. I will submit to faq but what are your thoughts.

[chalker7]

Good Morning All,

We just had our invitational and I was asked to help out judging along with a volunteer from another school. The question came up if this actually had to be a paddle wheelwith fixed blades or cups or could it be more of a ferris wheel with rotating cups. We did a quick check and could not find an answer. I will submit to faq but what are your thoughts.

Just from a practicality standpoint, how did they empty the cups at the bottom of the wheel?

[Science-dad]

That was the question. We were not sure it had to release the material. It did not drop the material at the bottom of its arc. It did raise the weight some small distance though.

[chalker]

That was the question. We were not sure it had to release the material. It did not drop the material at the bottom of its arc. It did raise the weight some small distance though.

Since the mass must be raised at least 10cm for the task to be complete, why did it matter whether or not the design is ok?

[Science-dad]

I guess because in theory it could work. Changing the size of the arbor for instance or having the string wrap to another point on the wheel.

That was the question. We were not sure it had to release the material. It did not drop the material at the bottom of its arc. It did raise the weight some small distance though.

Since the mass must be raised at least 10cm for the task to be complete, why did it matter whether or not the design is ok?

[Cheese_Muffin_Man]

I guess because in theory it could work. Changing the size of the arbor for instance or having the string wrap to another point on the wheel.

That was the question. We were not sure it had to release the material. It did not drop the material at the bottom of its arc. It did raise the weight some small distance though.

Since the mass must be raised at least 10cm for the task to be complete, why did it matter whether or not the design is ok?

Chalker, would something like that be allowed?

[chalker]

Chalker, would something like that be allowed?

Without seeing it, my gut instinct is that most people would not consider the device described as a 'paddle wheel'...

[Science-dad]

Keeping with that thought could a team increase the size of the arbor where the string is attached to the wheel. Say it was 1/4" through the wheel and increased to 1/2" where the string attaches to the wheel.

[chalker]

Keeping with that thought could a team increase the size of the arbor where the string is attached to the wheel. Say it was 1/4" through the wheel and increased to 1/2" where the string attaches to the wheel.

The rules pretty clearly state the string must wrap around the axle.. I'm not sure that would be within the spirit of it.

[losjackal]

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).

Yikes! I guess we need to remove this from our design. I suppose with a pulley to relay the string travel, it's too easy to accomplish even 30cm for Nationals.
So fundamentally, the spirit of the problem wants the axle of the paddle wheel at least 10cm+ above the ground, so the winding string can lift the mass from directly below.

What do people think about the winding string moving horizontally, hoisting a flagpole? The string could attach to the top of the flagpole (not sure about the length of travel necessary yet), or via lever action it could hoist the flagpole near the bottom if it has enough force. Either way, I think it's now introducing a lever to hoist the 10cm - 30cm, is it not? I would think that would be frowned upon just like a pulley, if my interpretation of the spirit is correct.
(I'm just trying to envision scenarios how this could work for 30cm, with the paddle wheel being near the bottom of the box. It's for a JV team so it doesn't matter much, I just love mechanical physics so the possibilities are fascinating to me.)