Simple Machines B/Compound Machines C

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Re: Simple Machines B/Compound Machines C

Postby slytherin » Sat Mar 14, 2015 4:20 pm

davidkim2106 wrote:OH!!! So what kinds of hooks would they be? Pictures would be awesome. Also, our lever doesn't seem to work, we use the right equation, but when we hang them directly (and then connect the two levers together with a string), our ratios are always off for some reason.

Any ideas? Thanks guys

Our team connected 2 zipties around the lever and then added a wire-like thing (that's not really like wire, but can bend and is strong, sorry for the REALLY bad explanation of what it is..) to the bottom of the ziptie so that it closed around the ziptie on one end and had a little U on the other end for you to hook the mass on.
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Re: Simple Machines B/Compound Machines C

Postby samlan16 » Sat Mar 14, 2015 6:24 pm

GoldenKnight1 wrote:
jayrey wrote:I found it after I posted. Thanks so much!! On another note, can we have our apparatus setup at the edge of the table so that the mass hanging down from the second class lever is hanging below the Lowest edge of the apparatus?


Though let me play the role of the mean event supervisor: Does your device work without the table? If not, did you impound the table? What if the supervisor is having you do this on the floor?

Just better to do what bernard suggested and elevate your fulcrum.

You could alternatively make your lever arm shorter if possible. That way, you are less likely to hit the table.
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Re: Simple Machines B/Compound Machines C

Postby joeyjoejoe » Sat Mar 14, 2015 6:51 pm

jayrey wrote:On another note, can we have our apparatus setup at the edge of the table so that the mass hanging down from the second class lever is hanging below the Lowest edge of the apparatus?


You could also prevent it from going down that far by putting some sort of stop on the lever. We implemented ours in the form of two nails 1" above and below the right side of our class 1 lever. That way, the lever couldn't go above or below balanced position by more than a few inches. This did create the need for a "quicker eye" when adjusting the lever but we came up with a solution for that as well - which I will share after all competitions are over. ;)

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Re: Simple Machines B/Compound Machines C

Postby davidkim2106 » Sun Mar 15, 2015 3:14 am

Anyone have any pictures of their device?
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Re: Simple Machines B/Compound Machines C

Postby boomvroomshroom » Sun Mar 15, 2015 3:17 am

davidkim2106 wrote:Anyone have any pictures of their device?


You could go in the image gallery.

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Re: Simple Machines B/Compound Machines C

Postby bernard » Sun Mar 15, 2015 4:41 pm

davidkim2106 wrote:Anyone have any pictures of their device?

A link to a picture of the device I made for our team.
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Re: Simple Machines B/Compound Machines C

Postby davidkim2106 » Sun Mar 15, 2015 5:39 pm

boomvroomshroom wrote:
davidkim2106 wrote:Anyone have any pictures of their device?


You could go in the image gallery.


Keep in mind I said pictures of their devices :)

bernard wrote:
davidkim2106 wrote:Anyone have any pictures of their device?

A link to a picture of the device I made for our team.


Thanks bernard :) Could you explain what the little things above the levers are? Also, where would you attach the masses? I don't see hooks

EDIT: nvm i see them, thanks :)
Sup.

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Re: Simple Machines B/Compound Machines C

Postby chinesesushi » Sun Mar 15, 2015 5:52 pm

bernard wrote:
davidkim2106 wrote:Anyone have any pictures of their device?

A link to a picture of the device I made for our team.


Thanks bernard :) Could you explain what the little things above the levers are? Also, where would you attach the masses? I don't see hooks

EDIT: nvm i see them, thanks :)


I believe those are levels that he uses to see whether the system of levers is in equilibrium or not, for more accuracy.
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Re: Simple Machines B/Compound Machines C

Postby goodcheer » Wed Mar 18, 2015 1:26 pm

bernard wrote:
davidkim2106 wrote:Anyone have any pictures of their device?

A link to a picture of the device I made for our team.



Bernard, I understand how the first class lever can rest in equilibrium, but how about the second class lever? Do you have a fixed counter-weight attached to it to the right of the fulcrum or do you adjust the first class lever to the point where it can balance the second class lever? Anyone else with idea please help. We just got someone new on this event. Thanks.

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Re: Simple Machines B/Compound Machines C

Postby bernard » Wed Mar 18, 2015 2:45 pm

goodcheer wrote:
bernard wrote:
davidkim2106 wrote:Anyone have any pictures of their device?

A link to a picture of the device I made for our team.



Bernard, I understand how the first class lever can rest in equilibrium, but how about the second class lever? Do you have a fixed counter-weight attached to it to the right of the fulcrum or do you adjust the first class lever to the point where it can balance the second class lever? Anyone else with idea please help. We just got someone new on this event. Thanks.

Yes, a fixed counterweight would let the second class lever rest in equilibrium, which would hopefully allow for more accurate predictions.
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Re: Simple Machines B/Compound Machines C

Postby UTF-8 U+6211 U+662F » Thu Mar 19, 2015 1:22 am

So... Apparently, there was a conflict, and now, I'm doing Simple Machines. What kinds of things should I do for simple machine concepts and terminology?

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Re: Simple Machines B/Compound Machines C

Postby chalker » Thu Mar 19, 2015 2:57 am

bernard wrote:Yes, a fixed counterweight would let the second class lever rest in equilibrium, which would hopefully allow for more accurate predictions.


But then it might not be considered a true 2nd class lever anymore... more like a hybrid 1st/2nd class lever....

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Re: Simple Machines B/Compound Machines C

Postby bernard » Thu Mar 19, 2015 4:50 am

chalker wrote:
bernard wrote:Yes, a fixed counterweight would let the second class lever rest in equilibrium, which would hopefully allow for more accurate predictions.


But then it might not be considered a true 2nd class lever anymore... more like a hybrid 1st/2nd class lever....

By the FAQ that states the the 40cm of the class 2 lever is just the distance between the fulcrum and effort points, could I call an 80cm beam a class 2 lever if the load and effort are on the same side of the fulcrum? I suppose the picture of our device I posted a while ago could be considered a hybrid since there is 5cm of meterstick opposite to the 40cm class 2 lever.
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Re: Simple Machines B/Compound Machines C

Postby joeyjoejoe » Thu Mar 19, 2015 11:35 am

Even with that definition, I would consider the class 2 lever actually a class 1 lever. It never even crossed our minds to build ours that way. Placing a counterbalance on a class 1 lever doesn't change its type but doing so with a class 2 arguably does.

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Re: Simple Machines B/Compound Machines C

Postby chalker » Thu Mar 19, 2015 5:13 pm

bernard wrote:By the FAQ that states the the 40cm of the class 2 lever is just the distance between the fulcrum and effort points, could I call an 80cm beam a class 2 lever if the load and effort are on the same side of the fulcrum? I suppose the picture of our device I posted a while ago could be considered a hybrid since there is 5cm of meterstick opposite to the 40cm class 2 lever.


As always, this isn't the place for official clarifications / comments.... Note that the purpose of that FAQ was to make it easier for people to construct the levers. It's REALLY hard to come up with a design that has the fulcrum exactly at the edge of the beam for example. Having a little bit of extra material overhanging the fulcrum doesn't significantly impact the functionality of the lever.

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