## Simple Machines B/Compound Machines C

TrueshotBarrage
Member
Posts: 29
Joined: February 8th, 2014, 8:15 pm
Division: C
State: AL

### Re: Simple Machines B/Compound Machines C

Thank you so much for the helpful replies! Initially I thought that d1 was the distance from the fulcrum to the end of the 1st lever

For connecting the two levers together, would one lever be on top of another? I was thinking so from the diagram, but now that I think about it, it wouldn't necessarily have to be connected.

Again, thank you all for these immensely helpful replies!
2015 Regionals
Compound Machines - 1st
2015 States
Bridge Building - 3rd

2016 Regionals
Air Trajectory - 1st

blindmewithscience
Member
Posts: 44
Joined: October 2nd, 2014, 8:57 pm
Division: C
State: NV

### Re: Simple Machines B/Compound Machines C

Connecting the two lever's doesn't have to be one on top of the other. My team decided to connect them with a screw through 2 drilled holes. Can post pictures of it in a few hours if wanted.

Nice explanation, Bernard.
Nevada state SO occurs on tau/2 day. Support the correct mathematical constant with all tauists.
http://www.tauday.com/tau-manifesto

Event: Regional/States
Astronomy: x/:(
Bungee: 3/3
Compound Machines: x/1
TPS: x/:(

TrueshotBarrage
Member
Posts: 29
Joined: February 8th, 2014, 8:15 pm
Division: C
State: AL

### Re: Simple Machines B/Compound Machines C

Wait, so if you connected them side-by-side, when the Class 1 lever moves up on the opposite side of the load (the right side), what would happen to the Class 2 lever? Wouldn't it break? Sorry if I have the wrong picture here, but I'm a bit confused on how you would connect the two without adding too much tension to the levers.

Thank you!
2015 Regionals
Compound Machines - 1st
2015 States
Bridge Building - 3rd

2016 Regionals
Air Trajectory - 1st

blindmewithscience
Member
Posts: 44
Joined: October 2nd, 2014, 8:57 pm
Division: C
State: NV

### Re: Simple Machines B/Compound Machines C

Wait, so if you connected them side-by-side, when the Class 1 lever moves up on the opposite side of the load (the right side), what would happen to the Class 2 lever? Wouldn't it break? Sorry if I have the wrong picture here, but I'm a bit confused on how you would connect the two without adding too much tension to the levers.
Thank you!
Agreed, that would be a problem, and we did face it. In order to fix it, we drilled a connection hole where they would be exactly at equilibrium. Then, on both levers, we extended that hole horizontally so that it would be free to move to the side if it wasn't at equilibrium, avoiding the problem of the tension.
Nevada state SO occurs on tau/2 day. Support the correct mathematical constant with all tauists.
http://www.tauday.com/tau-manifesto

Event: Regional/States
Astronomy: x/:(
Bungee: 3/3
Compound Machines: x/1
TPS: x/:(

bernard
Posts: 2010
Joined: January 5th, 2014, 3:12 pm
State: WA
Location: Seattle, WA
Contact:

### Re: Simple Machines B/Compound Machines C

As promised, here is a picture of our device.

"One of the ways that I believe people express their appreciation to the rest of humanity is to make something wonderful and put it out there."

joeyjoejoe
Member
Posts: 142
Joined: December 27th, 2012, 12:56 pm
Division: C
State: GA

### Re: Simple Machines B/Compound Machines C

Looks good but I noticed something you did that we started doing but then abandoned. Rule 3a states that each of the levers be made with a "single beam of length less than or equal to 40 cm". Even though you would like to have as long a lever as possible, we were afraid to make our class 2 lever 40 cm in length since this would require the beam used to make the lever to be slightly longer than 40cm (due to the loss at the fulcrum). We started with a beam of app 45 cm in length but then shortened it to 40cm. This made the actual lever only about 38 cm long. You appear to have a beam of approximately 45cm in your device. Have you had any competitions so far and if so, has this been mentioned?

bernard
Posts: 2010
Joined: January 5th, 2014, 3:12 pm
State: WA
Location: Seattle, WA
Contact:

### Re: Simple Machines B/Compound Machines C

Looks good but I noticed something you did that we started doing but then abandoned. Rule 3a states that each of the levers be made with a "single beam of length less than or equal to 40 cm". Even though you would like to have as long a lever as possible, we were afraid to make our class 2 lever 40 cm in length since this would require the beam used to make the lever to be slightly longer than 40cm (due to the loss at the fulcrum). We started with a beam of app 45 cm in length but then shortened it to 40cm. This made the actual lever only about 38 cm long. You appear to have a beam of approximately 45cm in your device. Have you had any competitions so far and if so, has this been mentioned?
I'm not on this event, I just happen to build a lot of stuff for our team so I don't know if the event supervisors have said anything about it. I've told our people on Compound Machines to mention the FAQs (which I've quoted below) if they run into issues withe the beam being longer than 40cm.

It would be better for the beam of the class 2 lever to be 80cm (with the fulcrum in the middle) because then it would be at equilibrium without any masses attached. With a 45cm beam, where effort is 40cm from the fulcrum, the beak is not at equilibrium without masses, which contributes to error.
For the first class lever component, does the total length of the bar have to be less than 40 cm or the individual sides from the fulcrum? (section: 3 / paragraph: a / line: 1)
For the class 1 lever the load point to effort point measurements must be less than or equal to 40.0 cm. The size of the the fulcrum is irrelevant to this measurement.

For class II lever would 40 cm be measured from the center of the fulcrum to the center of the load? (section: 3 / paragraph: a / line: 1-2)
The 40 cm maximum length will be from the fulcrum connection to the effort point.
"One of the ways that I believe people express their appreciation to the rest of humanity is to make something wonderful and put it out there."

Jaol
Member
Posts: 271
Joined: September 21st, 2014, 8:00 am
Division: C
State: GA

### Re: Simple Machines B/Compound Machines C

Does anyone know which event will switch out with Simple Machines next year as this is the 2nd year?
Countdown: 66 Days

samlan16
Member
Posts: 523
Joined: December 30th, 2013, 2:54 pm
State: TN
Contact:

### Re: Simple Machines B/Compound Machines C

Does anyone know which event will switch out with Simple Machines next year as this is the 2nd year?
I am guessing either Optics for both divisions or Physical Science Lab for B and Physics Lab for C.
Remember, we are proud of every team that participated and you are all winners.

chalker
Member
Posts: 2092
Joined: January 9th, 2009, 7:30 pm
State: OH

### Re: Simple Machines B/Compound Machines C

Does anyone know which event will switch out with Simple Machines next year as this is the 2nd year?
The tentative plan is Wind Power.

Student Alumni
National Event Supervisor
National Physical Sciences Rules Committee Chair