Trial and Error
Success, but then Failure
Over and Over
That's How You Make...
Table Of Contents
First Draft and Introduction
Why This for My Nueva My Page?
It all started one fine morning before I went to Violin Class. My dad had shown me an image of someone putting coins into a box. I didn't think much of it. Then the coins came out all neatly sorted and counted, which prompted me to think 'How did the coins just get sorted.'
Soon after, my dad and I left for violin class, when I asked him that question. He said he didn't know, but prompted me to think about it, but not to search it up. My dad told me to build it myself, and so, I decided to use this as my Nueva My Page.
First Draft Explained
The scan on the left displays my very first Idea. I would place the coins onto the ramp towards the top, and they would slide down. Notice how there are different slots of different widths with the hole on the top being the thinnest; for the dime, and the hole towards the base, being the thickest; for the quarter. My thought was that when a coin reached the first slot, it would either fall in as the hole was just the right size for it or slide over it. Like coding
if SizeOfCoin <= SizeOfHole:
FallDown
else:
GlideOver
But what I had hypothesized, didn't actually happen.
What Actually Happened
In short, every single coin I put onto the ramp, went into the first hole, the dimes hole. On the right, is a slo-mo, or slow-motion video on exactly what happened.
What Happened in the Slo-Mo?
The slo-mo video shows that the coin ended up slanting, at an angle before entering the hole. When the coin is slanted, the length of the base decreases meaning that it can now fall through the hole. - Figure 1
Why Did The Coin Slant?
The coin slanted because of center of gravity. Center of gravity, also known as the center of mass, is the average location where all the mass is. Similar to mean, but 3-D. We can also check that a point is the center of mass if it balances perfectly on your finger.
So, explaining this How it Works Style¹, why did the coin slant?
Figure 2
① Let's use a square in the place of the coin.
② The black dot on the coin signal's it's center of gravity
③ Even once the coin starts sliding down, it'll remain flat, or parallel to the ramp just as long as the center of mass doesn't exit the ramp.
④ Notice how part of the coin has passed the edge and is hanging over the hole, however, the coin won't slant, because its center of mass hasn't passed the edge yet.
⑤ Now finally, the center of mass has passed the line. Therefore causing the coin to slant and fall down.
In the End
The first draft didn't work, but I'm not one to give up,
my dad taught me a method of asking myself,
what my assumptions are, such as what am I doing, that can be changed, but I'm not changing.
I also document what worked, and what didn't work.
Even though my first draft failed, there's still more time to try
again and again.
And by looking at my assumptions,
I got ready to build
my prototype
of
the
second draft.
Second Draft
1
Why This Should Work
If the coin cannot tilt as it is vertical and leaning against a backboard.
it tilts, it must tilt away from the backboard which will not be possible.
Second Draft - Assumptions
As the first draft didn't work, I made a list of my assumptions, or certain designs of the coin sorter that I had "finalized" and thought wouldn't be changed.
Here is my list:
1. The coin slides down while flat
2. The ramp is sloped
3. The holes sort the coin from smallest to biggest.
The same list is also above and on the left.
How It Works
First, a coin is placed on its side on a ramp. It then goes through a machine that places the coin vertically as it drops through a chute. This time, the first hole is the largest. All the coins go through this hole except for the quarter which slides out through a ramp. The same thing happens at the second hole, where all the coins pass through except for the nickel.
In code, it would look like this:
if SizeOfCoin <= SizeOfHole:
FallDown
else:
GlideOver
Same code, different design. It didn't work
What Happened
The coin rolled along the backboard perfectly, until it got to the hole.
Once it got to the hole, trouble started. The quarter, which was
supposed to roll over the hole, got stuck in the hole.
The nickel as well.
So did the penny.
The only coin that made it through confidently was the
dime.
Why Did It Not Work?
As for now, I had no idea why this didn't work.
My main hypothesis was that the coins weren't moving fast enough
to pass over the hole,
instead, they got stuck inside the hole.
To test my hypothesis, I decided to increase the slope of the ramp.
After taking some slo-mo's I discovered, that when the steepness was
increased, the coin would simply loose contact with the ramp, and fly off.
QUARTER
NICKEL
PENNY
DIME
Why Did It Not Work? - Continuation
Eventually, once I decided to skip ahead and come back to this later,
I found my cause for why it didn't work.
Time to explain it. How It Works Style¹
Or rather, how it doesn't work style.
This is a bit complicated, so get ready for some simple math!
« Figure 3
① We have two coins, coin 1 and coin 2. The diameter of coin 1 is signaled by line Da.
② The diameter of coin 2 is Db.
③ As coin 1 is larger than coin 2, notice how we can fit line Db onto coin 1
④ Once coin 2 has rolled down the slope, and into to it's corrective hole, notice how, for a split second, line Db aligns with the slope of ramp.
⑤ The reason why coin 2 can fall into the hole, is because there is a small amount of space between the coin, and the edge of the ramp.
⑥ Now notice how coin 1 is rolling down. Remember that line Da is the diameter of coin 1, and Db is the diameter of coin 2.
⑦ Once coin 2 has reached the hole, line Db immediately matches up with the slope, but alas, the coin is too big to fit into the hole, even if line Db can.
⑧ NOTE Point Db is not actually only in one place. Because once I place line Db coin 2, it does not touch opposite ends of the circle while passing through the center, it is no longer the diameter. Line Db is now called a chord. In my demonstration, I had line Db on only one spot on coin 2, however, I could have placed it anywhere. As seen in the image, Line Dc has been placed all around the circle.
What Works
See image on left.
What Works
See image on left.
What are My Assumptions?
See image on left.
CONTINUATION
Figure 3
Brainstorm Page
Weight
Diameter
Thickness
2.268g
.08oz.
Dime
Penny
Nickel
Quarter
2.5g
0.088 oz
5g
0.17oz
5.67g
.2 oz
18mm
.7 inch.
19mm
.75 inch.
21mm
.8 inch.
25.4mm
1inch.
?
?
?
?
Third Draft?
I am stuck.
I do not know what to do now.
When I get stuck, I write my thoughts down on a sheet of paper.
On the left side is the page I made for brainstorming.
Problems:
I started by writing down my problems and thinking about ways to solve them. Most of my work is shown on the left. I will remake the coin specifications (shown at the bottom of the scan) as it is a bit messy.
NOTICE:
The Dime and Penny have very similar dimensions
The nickel and quarter also have very similar dimensions.
If I were to change the steepness of the ramp based on weight, it would have to be very precise.
How I made my third draft:
As seen on the scans by my very messy handwriting, you can see a note called AHA!
In all my previous drafts, the coin dropped down into a hole.
my next step would then be to challenge that assumption and make the hole in the side
Time to make my third draft!
And hope it succeeds!
Note: The notice towards the bottom of the page means that it requires the coins to either fit into the hole or not.
Third Draft
After The Brainstorm Page
Upon challenging my assumption, of the hole for the coin to drop through being on the bottom, I set to work building my very first draft of the 3rd Draft. This time with the hole built sideways.
How It Works
First, a coin is placed sideways on a slanted ramp. It'll reach the first hole, where if it's too big, it'll glide on past to the second hole. If the coin is the right size, it'll fall on it. I noticed that the my cuts would have to be extremely precise because the coins have a similar diameter.
In code, it would look like this:
if SizeOfCoin <= SizeOfHole:
FallDown
else:
GlideOver
Same code, once again, a different design. This time? It worked. I was extremely happy. Only, why didn't the coins slant into the hole, or become stuck in the hole like the previous two drafts? To explain? It's How it Works ¹ time!
Final Notes?
I finally did it!
After a long time working, prototyping, and testing,
I finally did it!
I found out almost exactly what was
inside that box that my dad showed me!
I'm assuming, that this is what's inside the box, but curved.
There will also be sensors that dictate when a coin falls out of the hole.
Anything Else?
I'm still not satisfied.
Although, I found a method to sort coins,
I still need to find a way to count them.
I also still need to find out how to put in many coins at once, and still get sorted.
But still, I'm overjoyed that I finally solved this problem.
Without searching it up,
and using my brain instead.
How It Works Explanation
« Figure 4
① For sake of explanation, I will simplify the drawing to include only two holes. The quarter, and the dime's hole. Notice how a quarter is at the start ready to roll down.
② As the quarter rolls into the dimes hole, it does not fall down, as it is being supported on the top by the wooden board.
③ There is no three as I have accidentally skipped over it in
④ Notice how once the quarter rolls into the hole in which it is destined to fall into, there is no more supporting board on the top. Therefore, it falls in.
⑤ Please note that I am not entirely sure about this explanation. My only question is on note #5. Notice how the center of mass/gravity has passed the border and is hanging over the hole. Why then, does the coin still remain upright? My current hypothesis is that gravity is pulling the coin downwards, not sideways. I will have to test that hypothesis.
My initial make of the third draft was with cardboard. Very flimsy.
"I Did It!" I found out how to sort coins!
Photo Collage
The Acknowledgements
I couldn't have done this without any help from anyone. I am grateful to everyone who helped me, and helped me be my best and put forth my best effort. I will also put forth acknowledgements and notes for software, and hardware I used in the making of this project.
MY DAD
My dad for showing me the video of the coin sorter, and staying with me the whole way through. He challenged my thoughts always asking why, and pushing me to explain deeper.
MY MOM
My mom for asking me why this project in specific. Why not any other? I thank her for always looking at this project as if she disapproved of it. That helped me single down, and try to explain my thoughts more carefully.
MY SISTER
My sister for lending me her piggy/unicorn bank for 0% interest. I wouldn't have been able to test any of my prototypes without any of her coins. I do not have coins, as I generously donated mine to my sister once I started keeping track of my money digitally on a spreadsheet. (My dad is teaching me how to manage money, and gives me an amount monthly)
MY FRIENDS
My friends for telling me about many of the software you see listed below from Blender, VN, Final Cut Pro, Manycam, and Wix. Without them, this page may not have even been created.
BLENDER
Blender for massively helping me with my 3-D animations. This project would've been completely different without those animations. Although a hard software to use, there are many tutorials online which helped me learn it better. Blender is an open-source software. you can download it at blender.org for free.
YOUTUBE
For helping me learn how to use Blender. I started using Blender completely from scratch with no knowledge, and as Blender is extremely difficult, I had to learn how to use it. I watched many tutorials on YouTube which helped me learn how to use it.
VN & IMOVIE
SOME FINAL CUT PRO
Yes, I used two video editing softwares. I did download the free trial version of final cut pro, but I found it slightly unconventional. I then used VN, as it had cool transitions and texts. To further polish my video, I moved the video to iMovie, where I used some features only available there, to maximize the quality of my video. Both are great video editing softwares.
Download the Free Trial of Final Cut Pro at apple.com/final-cut-pro/trial/
MANYCAM
Manycam is a camera system used to create special effects on the camera. I was originally planning to do just that but ended up just using it to export videos onto my computer. My computer has the best video quality of my other devices. Download Manycam at manycam.com
DJI
I used the DJI Action 2 to film the slo-mo videos. I was greatly impressed by the slow motion It can also shoot amazing videos with a great field of view. For more info go to www.dji.com/dji-action-2
WIX
Wix was the cause of this page. I made it all on their website creator, and even though there is a link at the top of this page, I still need to credit them in the acknowledgments. Without them, my page wouldn't have any aesthetics.
APPLE
I used apple devices for the rest. All editing and animation was done on a Macbook, and even the creation of this My Page was done on it as well. Its devices are superior, and I must say airdropping is their greatest invention.
₁ How it Works is a magazine explaining how it works.