how to put together a DIY cube

[zuko]

i just got my cube in the mail today and i dont want to assemble it wrong, im guessin you assemble it just like a regular one, but there are small little squares with a cut off corner but i dont know were they go >.<

 

[aznblur]

Those pieces, you put into the corner pieces. Make sure you put it in so that the smooth side is facing out.

 

[pjk]

Yes, those little pieces go into the corner to make it so you can't see the "hollow-ness". Ask if you need further help.

 

[dChan]

I don't bother putting those in. Like I said in other topics, it reduces friction(increasing the work efficiency of the cube) which makes it a bit faster, but prone to more lockups if you have the gap facing in an un-uniform way. My gasps face inwards toward each other.

 

[aznblur]

Not putting the pieces reduces friction? Seems odd to me.

 

[pjk]

Yeah, I don't really see it that way at all. I put mine in and it works ideal to what I want. I guess you can try both ways... but I don't see any negatives to having them in.

 

[dChan]

lol. Less surface area means less friction. Haven't you guys watched the Magic School Bus? Or have a science class?

 

[Erik]

hmm, why are 'klapschaatsen' faster than older skates then? The idea is that the skate has more (longer) contact witht the ice..

 

[deKeijzer]

Originally posted by dChan@Apr 18 2007, 06:37 PM
lol. Less surface area means less friction. Haven't you guys watched the Magic School Bus? Or have a science class?

But a smoother surface allso causes less friction then a rough surface. (mostly, because friction is a really really strange thing)

I think it will cause less friction because the sharp edges of the corner pieces are then filled. Causing it not to grab other pieces.

 

[zuko]

lol thanks guys i got it together without messing up, i just never really took one apart so i was confused. i decided to put the corner things in, i cant really tell a diff. with or without. but i like the cube in general, its smooth lol

 

[dChan]

Locking up is not due to friction, it is due to you increasing the chance by x% for it to lockup because you removed the peice.

Now to address the iceskating concept: This is a different concept, not friction. The longer the skate, the more surfae the skater can use to exert on the ice and increase his power. A smaller skate has less surface to exert on the ice and thus is unstable and doesn't allow the user to push away from his starting position. Skater A with a longer blade is better because he can use more power but that does not mean he has less friction- it just means he is able to use more power to overcome the friction.

Put your hand flat across a table and try to simultaneously push down and move it forward with your hand flat. Now do it with one finger. The smaller surface area of the finger can move much easier.

The Rubik's Cube is a tool- and all tools lose work that the user inputs due to friction. Therefore by reducing the pieces' surface area, less work is need to do work on the cube. Which increases its work efficiency.

 

[deKeijzer]

Comparing your hand to a plastic isn`t that right.. I don`t think it is a simple case of yes/no. You should test it out for yourself, and if you even notice the difference, choose what you like best.

 

[Arakron]

Originally posted by dChan@Apr 18 2007, 08:58 PM
Locking up is not due to friction, it is due to you increasing the chance by x% for it to lockup because you removed the peice.

Now to address the iceskating concept: This is a different concept, not friction. The longer the skate, the more surfae the skater can use to exert on the ice and increase his power. A smaller skate has less surface to exert on the ice and thus is unstable and doesn't allow the user to push away from his starting position. Skater A with a longer blade is better because he can use more power but that does not mean he has less friction- it just means he is able to use more power to overcome the friction.

Put your hand flat across a table and try to simultaneously push down and move it forward with your hand flat. Now do it with one finger. The smaller surface area of the finger can move much easier.

The Rubik's Cube is a tool- and all tools lose work that the user inputs due to friction. Therefore by reducing the pieces' surface area, less work is need to do work on the cube. Which increases its work efficiency.

Sorry, but you're wrong. Friction is proportional to the properties of the two surfaces in contact, as well as the force being exerted between them. It is has nothing to do with surface area. I don't know much about skating, but with a longer skate you exert the same force over a larger area, which reduces the pressure. Stuff happens at the contact between the skate and the ice, such as the ice momentarily melting due to the pressure, so this isn't a good example for looking at just friction.
As for the hand on table example, you can put your whole weight behind your hand if it's your palm/heel of your hand. You can't push as hard through your finger - ask someone who can do a handstand to go on the tips of their fingers, or try to do a pushup on just your fingers. And those examples are 5 times less extreme, since there are 5 fingers rather than 1.

Long story short, friction is dependent only on the surfaces and the forces, not the surface area. As for the question at hand of the corner caps, the post before me is right on.

 

[dChan]

Originally posted by Arakron@Apr 18 2007, 01:14 PM
Sorry, but you're wrong. Friction is proportional to the properties of the two surfaces in contact, as well as the force being exerted between them. It is has nothing to do with surface area. I don't know much about skating, but with a longer skate you exert the same force over a larger area, which reduces the pressure. Stuff happens at the contact between the skate and the ice, such as the ice momentarily melting due to the pressure, so this isn't a good example for looking at just friction.
As for the hand on table example, you can put your whole weight behind your hand if it's your palm/heel of your hand. You can't push as hard through your finger - ask someone who can do a handstand to go on the tips of their fingers, or try to do a pushup on just your fingers. And those examples are 5 times less extreme, since there are 5 fingers rather than 1.

Long story short, friction is dependent only on the surfaces and the forces, not the surface area. As for the question at hand of the corner caps, the post before me is right on.

You sort of said what I said. If friction is proportional to the properties of the two surfaces in contact, then the less contact the two surfaces have, the less the friction? Isn't that what you are saying?

 

[Arakron]

Originally posted by dChan@Apr 18 2007, 09:18 PM
You sort of said what I said. If friction is proportional to the properties of the two surfaces in contact, then the less contact the two surfaces have, the less the friction? Isn't that what you are saying?

No, the properties of the surfaces are what they're made of. The frictional force is equal to the force between the two objects (normal force) multiplied by a number called the coefficient of friction, which is a constant for the two materials in contact. So a teflon-teflon contact has the lowest coefficient of friction. Sandpaper-sandpaper is very high. But with the same force between them, the area of the contact does not change the friction.

Another way to think about this is with something that requires high friction, like shoe soles. They are made of rubber, which has a high coefficient of friction with most other surfaces, but you don't see them being extended to be bigger - in fact, in many shoes the area under the foot's arch does not touch the ground.

 

[dChan]

Well, just try it for a while. I have a science book right here that says what I am saying(even gives the skating example in terms of friction). I've been cubing without the corner-pieces and afterputting them back on it felt really weird to cube. Like heavier or something- I can't explain it well, but it makes me feel wobbly as I cube. Like I can't go fast(my time was 39.26 sec just now when I did a random solve). Maybe I'll practice more with the corner-pieces in so I can get used to it, but it doesn't feel the same as when I'm doing solving at super speed without the corner pieces.

 

[AvGalen]

Just go with what you like.

Friction is a strange thing and some might even like it on a cube. An ideal cube for me would have enough friction to stay perfectly stable and aligned when you hold it. Then just a tap should turn it exactly 90 degrees as fast as possible. After that turn, friction should provide me with a stable and aligned cube again. Actually, I would love to have this cube in real live.