Wednesday, July 31, 2013

Making a Clasp on Bracelets

Some bracelets just need a clasp in order to take it on and off.  The duct tape bracelets that I make generally do not have a clasp because they are a bit difficult to make and are not easy to unclasp.  However, I have devised a way to make a clasp out of duct tape to replace any broken clasps or to add one to a duct tape bracelet.

To show how to make a clasp, I will use a bracelet called a two-chain bracelet as an example.  A two-chain bracelet is essentially two loops (or chains) connected together.  To make the two loops, I cut two pieces of duct tape that were the length of my wrist, and I rolled them up.

Rolled pieces of duct tape
To make the clasp, I took one of the rolls and folded it in half.  I made a circle with the roll by wrapping the same piece of duct tape around both ends.

One chain done
For the other roll, I wrapped one end with the same color duct tape I used to connect the two ends of the first chain.  On the other end, I needed a keeper, like the one I made for a watch.  However, I made it with a slightly different process.  I first cut a section of the duct tape and folded it over.


I then trimmed the piece of duct tape so the height matched the height of the piece of duct tape folded over.


I attached the strip to the other end of the rolled up duct tape.


To finish the bracelet, I looped the two chains together and then tied a piece of thin duct tape around the two strands of the second chain so that when the bracelet was unclasped, it did not fall apart.

Finished!
The clasp works really well and looks stylish, especially with the silver duct tape, which, at a very quick glance, looks like real silver.
On human

Which Header Should I Use?

My current header is made out of duct tape, which I like, but it does not have the correct title of the blog.  I made a new header, but I cannot decide between two versions of it.  The two (rough draft) versions are below.
Version 1 
Version 2
Please comment on which version you like better and why.  Add any other comments or opinions you have, such as whether or not you like it.  Feel free to give me advice on how to improve it, if you do not like it.  Thank you for your help!

Sunday, July 28, 2013

Fun with Calculus: Modeling Volume of Solids with Known Cross Sections (Part 2)

Read Fun with Calculus: Modeling Volume of Solids with Known Cross Sections (Part 1) before reading Part 2.

To attach each cross section I made, I used the extra yarn at one end to weave through the base.  I did not tie any knots; I just weaved the yarn through many times.

The first square 
Attached 
More cross sections attached
As the squares got bigger, the extra yarn at the end was not long enough.  I did not think ahead when I was making the squares that I would be using the ends of the yarn to attach them to the base, so I needed to extend the yarn.  I tied more yarn to the end and proceeded to weave through the yarn.

Tied with a simple knot
About halfway done
When I finished attaching all of the squares, they were a little floppy and were not straight.


To solve this problem, I weaved through the top corners of each square to attach them together and hold them in an upright position.

Corners attached
The completed "solid" looks pretty cool when examined from different angles.  It is definitely a great visual if one is learning about how to solve for the volume of solids with known cross sections.
View from the top

Saturday, July 27, 2013

Fun with Calculus: Modeling Volume of Solids with Known Cross Sections (Part 1)

Using the model of the area in between two curves from the previous post, I decided to create solid with known cross sections.  Information about the volume of solids with known cross sections can be found here or there.

For my project, I chose a square cross section.  The idea behind cross sections is that each slice has an infinitely thin thickness.  However, yarn is not infinitely thin, and crocheting a square for every single slice that can be made takes up a lot of yarn, so I only made 15 slices to be evenly spaced out.  Just keep in mind that there will be spaces in between each cross section in my model, spaces which should not exist.

Each square cross section I made had a side length that corresponded with the difference between the y-values for f(x) and g(x) at different x-values.
First cross section I made
Another, bigger cross section
 I will attach each cross section on perpendicular to the base, which is the model of the area between the curves f(x) and g(x).

An idea of how each cross section will be attached
Each cross section I made generally increased in size, since as the x-value increased, the y-value generally increased until the vertex.  After, each cross section decreased in size.

5 of the cross sections I made
To avoid confusion before I attached each square to the base, I stacked the squares up in increasing side length.  The two piles represent the squares that belong to the portion of the solid that is to the left of the vertex and the remaining squares that belong on the other portion of the solid that is to the right of the vertex.

All of the square cross sections I made
To see the final project, go to Part 2.

Fun with Calculus: Modeling Area Between Curves with Yarn

A major part of calculus includes finding the area under a curve.  Before he or she learns about integration, a calculus student learns about approximating area under curves by means of a method called Riemann sum.  To find more about Riemann sums, visit Khan Academy or Paul's Online Notes.

I noticed, while previously crocheting, that each row resembled a rectangle that could be placed underneath a curve to approximate the area.  If I were to crochet enough rectangles, I would have a Riemann sum approximation of the area under a curve.

I chose two random functions, f(x) and g(x), and drew them on a piece of paper.  As far as I know, these are functions that I just drew on paper and cannot be resembled by any equation.
f(x) and g(x)
I then crocheted a shape to model the area between the curves, which is solved for by subtracting the area of f(x) from g(x).  According to the Riemann sum approximation method, one should choose between a left-hand, right-hand, midpoint, or trapezoidal approximation.  I chose none of those options, since I did not really think about that.  I have a combination of a left-hand and a right-hand approximation.

Model of the area between f(x) and g(x)
Placed on the graph, the crochet model about approximates the area between the curves.  It does not fit perfectly, as it is only an approximation.

Thursday, July 25, 2013

Fixing a Book with Duct Tape

As many know, duct tape is used for more than just pencil cases, which is what I have mostly used duct tape for.  Duct tape serves a useful purpose, such as fixing car windows, which I see all the time on the road.  It can also be used to fix the binding on a book and to reattach the covers to the book.

The big dictionary in the house has had a ripped cover and binding for years.  Nobody has sought to fix it, but since I had red duct tape that matched the color of the dictionary, I thought that this was a perfect opportunity to reconstruct the spine.

Starting condition
I first needed to fix the spine, which, as seen in the pictures, was ripped and half-missing.  I removed the front and back covers from the dictionary and began working on the back cover.


I taped what was left of the spine and the back cover together on the back and the front.


To recreate the missing part of the spine, I alternated between putting pieces of duct tape on the inside of the spine and on the outside of the spine until I reached the end.  I also taped up the rip on the top of the spine between the two remaining pieces of the spine.


To connect the front cover with the spine, I just taped them together, both on the inside and the outside.
Two covers attached together
Inside view in between the two covers
I put a piece of tape horizontally along the bottom edge of the spine, which is the portion of the spine that I reconstructed with duct tape.
Bottom half

Front and back cover with no pages
To reattach the pages, I placed the back cover underneath the bound pages and taped them together.

Starting to bind the pages to the cover
I repeated the same process at the front of the book, binding the insides together.  I placed a piece of duct tape on the other side of the where I joined the pages and the cover together at both the front and the back of the dictionary.

Tape between the pages and the cover to hold them together
After attaching the cover to the spine, I finished the reconstruction of a book spine and the attachment of the hardcovers to the pages.  The dictionary, I must say, looks so much better than before.

Monday, July 22, 2013

Inside a MagSafe Power Adapter for Macbooks

Recently, my MagSafe charger for my computer stopped working because the wire connecting the adapter to the computer completely separated.  I went out and bought a new one but could not decide what to do with my old one.  I had it for four years; I was not just going to throw it away, so I decided to open it.  Even though it may not look like it, the adapter box was really difficult to open.  The plastic shell pieces were glued together, and trying to crack open the case by simply driving a screwdriver in between was ineffective.  We eventually got it open, and this is what we saw.

Basic parts
Cover, difficulty of opening the box can be seen
One of the hooks the wire wraps around




Separating the case from the insides
Encased in copper sheets
Copper sheets taken off




Random close-up of the contents
Reassembled and put back in the plastic shell
The contents were in great condition; if only Apple could make the wire better quality, I would have been able to use the power adapter for the entire lifetime of my computer.