Screw

[Unome]

That would be pretty difficult to defend using the rules' definition of a screw. I'd suggest using one of the options tha kinghong mentioned above (especially the first one, as that is probably easier to defend as legal to an event supervisor).

I'm sorry I'm new at this. When you say the "object rotating about the screw" you don't mean the marble in it? Can you recommend any resources to help me visualize what you are saying?

I do not understand the marble going THROUGH the screw. Do you mean the marble will go around the threads? Whatever your choice, how will the marble go through? The screw will have to turn at some point. A screw doesn't just turn or have something go around it, it has to go in a forward or backwards motion depending on the threads. like a real screw... This shows that the screw WILL indeed have to turn. 2 rounds in the minimum. Hope this helps...THX

I think what MaeleeB is talking about is something like an Archimedes screw with a marble inside.

[cookie75]

I'm sorry I'm new at this. When you say the "object rotating about the screw" you don't mean the marble in it? Can you recommend any resources to help me visualize what you are saying?

I do not understand the marble going THROUGH the screw. Do you mean the marble will go around the threads? Whatever your choice, how will the marble go through? The screw will have to turn at some point. A screw doesn't just turn or have something go around it, it has to go in a forward or backwards motion depending on the threads. like a real screw... This shows that the screw WILL indeed have to turn. 2 rounds in the minimum. Hope this helps...THX

I think what MaeleeB is talking about is something like an Archimedes screw with a marble inside.

I see but i am not sure this would count as a screw for points in the rules.

[torqueburner]

I was planning a stationary screw that doesn't move itself, but that a marble would move through it. But after reading the rules, it sounds like the screw itself needs to move, not just the marble. I'm confused.

If you look at rule 4.d.v., "Screws must complete at least two full rotations. . .", it seems pretty clear that this implies that it is the screw that must rotate. Aside from that, with a stationary screw, I don't see how you could satisfy rule 4c., which says that ". . .both simple machines must use mechanical advantage to transfer energy."

[kidcoder923]

how do you plan to turn the screw?

[rajeshgoel]

I checked with soinc.org and object coming on a spiral ramp will not be considered as a screw machine action.

[kidcoder923]

so then will it count as an incline plane?

[goodcheer]

I was planning a stationary screw that doesn't move itself, but that a marble would move through it. But after reading the rules, it sounds like the screw itself needs to move, not just the marble. I'm confused.

The screw must turn or rotate, but the screw itself does not have to move forward or backward. It can turn and move an object like a marble forward or backward depending on the rotation of the screw. The word "stationary" seems to need clarification. If you use a screw driver to turn a screw, in common usage, the screw moves forward into an object such as a piece of wood. In this usage of a screw, the wood is stationary. But, if the screw is stationary (that is you prevent it from moving forward or backward) and you turn the screw, a piece of wood can move along the threads of the screw as long as the wood is not stationary. There are many examples where this is used, such that when the screw is turned, it tightens an object but it stays in place, such as in a computer case.

[mderoller]

We would like to connect a wheel and axle to a screw in such a way that both are scorable. One idea is for a weight attached to a string that is wound around the wheel to fall, there bye rotating the axle. Can the rotating axle power the screw directly and still be scorable as a wheel and axle and a screw?

[mderoller]

Nevermind, after rereading the rules, specifically 3i I understand "each object that is a simple machine may only be counted as a simple machine once". In my example it can be a scored as a wheel and axle, or screw, but not both.

[goodcheer]

Nevermind, after rereading the rules, specifically 3i I understand "each object that is a simple machine may only be counted as a simple machine once". In my example it can be a scored as a wheel and axle, or screw, but not both.

It seems what you are describing is that the screw would simply be an extension of the axle, so you are probably correct. However, if you connected a second string from the axle to the screw, then you would have a wheel and axle transfer to a screw and both would count. The problem becomes, how to turn the screw. What if you did two of the same set ups in a row and called one of them the wheel and axle and the other one a screw? You can place a spool on the head of a screw, such that when the spool turns, the screw turns. Seems to be the same idea you have. Happy possible mission.