Screw Task

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Unome
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Re: Screw Task

Postby Unome » December 4th, 2018, 3:12 pm

would i be allowed to have a screw task that is actually a pulley (but only 1 wheel), which is pulled by the force of gravity (a mass), and moves another mass or so 2 cm upwards? i just want to know if this technically works (i am converting rotational force into linear, would it just be a matter of wording it properly?)
I would say this doesn't fit the definition of "operating as a screw" in rule 4.b.ix.
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Re: Screw Task

Postby Flavorflav » December 9th, 2018, 4:59 pm

If you attach an object to the screw does it count as a separate object or part of the screw
I would consider it to be part of the screw.
I wouldn’t. The event description never specified that the moved object has to be removable or unattached.
I would consider an attached object to be a part of the screw if and only if it rotates with the screw.

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Re: Screw Task

Postby Flavorflav » December 9th, 2018, 5:01 pm

Do we think that the screw must be in contact with the object it is moving for the whole time? For example, if the screw was moved horizontally only about one centimeter, but made contact with a ball, hitting it and causing it to roll for an additional one or two centimeters, would that satisfy the rules?
The descriptions states that the screw must achieve two tasks: operating as a screw AND moving an object 2cm. I would argue if you bump a ball and simply allow it to roll, gravity is moving the ball for most of that 2cm, not the screw.
I wasn't thinking about using gravity or a ramp. If a screw with wide enough threads is turned fast enough it could hit a small ball and get it to roll across a flat surface. In this case, the screw would be providing all of the energy that the ball needs to move, but the screw would not need to move the full 2 cm itself.
You would have to convince me that the surface was indeed level, which might not be easy to do. It would be safer to make it incline slightly upward, so that it is clear that there is no gravity-assist.

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Re: Screw Task

Postby Unome » December 9th, 2018, 5:33 pm


The descriptions states that the screw must achieve two tasks: operating as a screw AND moving an object 2cm. I would argue if you bump a ball and simply allow it to roll, gravity is moving the ball for most of that 2cm, not the screw.
I wasn't thinking about using gravity or a ramp. If a screw with wide enough threads is turned fast enough it could hit a small ball and get it to roll across a flat surface. In this case, the screw would be providing all of the energy that the ball needs to move, but the screw would not need to move the full 2 cm itself.
You would have to convince me that the surface was indeed level, which might not be easy to do. It would be safer to make it incline slightly upward, so that it is clear that there is no gravity-assist.
Also consider that you need to take into account the possibility of a tilted table, if a tournament forces you to use a table (or a tilted floor, for that matter)
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Re: Screw Task

Postby TheSquaad » December 9th, 2018, 8:01 pm

I would consider it to be part of the screw.
I wouldn’t. The event description never specified that the moved object has to be removable or unattached.
I would consider an attached object to be a part of the screw if and only if it rotates with the screw.
Imma post an faq about this. In my mind there should be no issue as long as the piece is removable, but I feel like the nats board should clarify this

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Re: Screw Task

Postby C8H10N4O2! » January 8th, 2019, 6:40 pm

If I have the screw turn to release an object that it is holding up, would that count as converting rotational to linear? I'm asking because the object drops straight down, and therefore is also technically moved by gravity, even though the screw allows it to move.
And if so, is this just a case of carefully wording my ASL?

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Re: Screw Task

Postby PM2017 » January 8th, 2019, 9:23 pm

If I have the screw turn to release an object that it is holding up, would that count as converting rotational to linear? I'm asking because the object drops straight down, and therefore is also technically moved by gravity, even though the screw allows it to move.
And if so, is this just a case of carefully wording my ASL?
No, because gravity has to be the force turning the screw.
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Re: Screw Task

Postby C8H10N4O2! » January 8th, 2019, 10:41 pm

If I have the screw turn to release an object that it is holding up, would that count as converting rotational to linear? I'm asking because the object drops straight down, and therefore is also technically moved by gravity, even though the screw allows it to move.
And if so, is this just a case of carefully wording my ASL?
No, because gravity has to be the force turning the screw.
But if gravity is the force turning the screw, then the screw turns 2 rotations (or more), which causes the object to fall (more than 2cm), it technically fits the rules?

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Re: Screw Task

Postby Vstorm34 » January 9th, 2019, 8:57 am

If I have the screw turn to release an object that it is holding up, would that count as converting rotational to linear? I'm asking because the object drops straight down, and therefore is also technically moved by gravity, even though the screw allows it to move.
And if so, is this just a case of carefully wording my ASL?
No, because gravity has to be the force turning the screw.
But if gravity is the force turning the screw, then the screw turns 2 rotations (or more), which causes the object to fall (more than 2cm), it technically fits the rules?
In this case, the object's descent is triggered by the screw, but it is moved by the force of gravity, not by the screw.

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Re: Screw Task

Postby TheSquaad » January 10th, 2019, 5:07 am

No, because gravity has to be the force turning the screw.
But if gravity is the force turning the screw, then the screw turns 2 rotations (or more), which causes the object to fall (more than 2cm), it technically fits the rules?
In this case, the object's descent is triggered by the screw, but it is moved by the force of gravity, not by the screw.
An easy fix to that is have the object you want to fall be on a 1st class lever (swing By horizontally), and have the screw push the other side of the lever


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