Here you'll find an assorted mix of content from yours truly. I post about a lot
of things, but primarily
Shenzhen Adventure Day 30
06 Jul 2015
The smell clock is a device I built for the Shenzhen manufacturing bootcamp. While we were there,
we had a challenge to build a prototype on a tight budget. The assignment was to build something
that could denote the passage of time.
I decided, while walking around the market, that these little bottle top humidifiers were really cool:
So I knew I had to incorporate them. I walked around the market scoping out
prices and couldn’t find them for a good deal. Just when I was about to give
up, I found them at a price I could afford – if I recall it was a few dollars
a piece, but I needed a lot.
I laser cut a case for each humidifier out of acrylic and opened up each humidifier and attached a wire
to trigger the toggle switch.
In order for it to look nice, I needed some good looking bottles, so I hit the grocery store, where I found:
A bicycle built from toothpaste.
I didn’t find any nice bottles, so I ended up using some ugly ones.
The design uses 4x4 grid of individually controllable humidifiers connected to an arduino mega. Each of the bottle is filled with different fragrances.
I ended up running into trouble with the plastic case, so I cut a new one from wood.
And the finished product:
Shenzhen Adventure Day 25
01 Jul 2015
Wirebonding is a technique you’re probably familiar with if you’ve ever taken
apart a cheap toy.
It’s a slightly harder technique to employ than using a standard packaged chip,
but if employed correctly can help reduce cost (raw die is cheaper), footprint,
and weight. The cost per wire is really small!
Basically, rather than solder a chip down, you paste it down and then solder a
small wire from the chip die to the board and then cover it in goop to protect
it.
This technique used to be really hard to access, but with more automation costs
have come down drastically making this an interesting technique for a
cost-concious engineer.
The factory boss here was a very friendly lady, and she gave us an awesome tour!
Example of a finished wire bonded board.
A worker, by hand, places the tiny raw dies onto the circuit boards using little wooden chopsticks.
The dies are really tiny to be working with by hand!
An employee configures the machine. In the upper left, you can see a wiring
diagram, as well as a computer showing the current alignment.
The wirebonding machine drops small conductive wires from the bond points.
Go! Go! Go!
After wire bonding:
Ok… maybe this is before, I can’t recall. The wires are hard to see…
If there is a mistake, a worker uses a machine to correct it. The machine has
knobs which scale each human movement down by a factor of 10. This allows them
to do the detailed work needed to operate on these tiny wires.
Afterwards, the boards have protective goop placed on them.
Goop laying machine.
The boards then go into an oven to cure the goop to a hard shell.
They can also do clear goops!
Shenzhen Adventure Day 25
01 Jul 2015
When you make a lot of a board, you get a fully automated SMT line. But what about when you only make 5?
Programming a SMT line takes time and is expensive. So you can do the dumb thing – do them by hand!
Yes, even though the components are tiny the employees are highly skilled with surgically precise hands.
When you’re getting hand done SMT, it’s obviously at a smaller scale, so things
are a bit more laid back you could say.
E.g., there was a random cat hanging out.
First, schematics and PCBs come in and are marked up to help the workers place parts.
Silk screens get made to put the solder paste down.
Parts get carefully placed onto the boards.
The workers have really steady hands :)
Lastly, as with any SMT process, the boards get sent to the oven.
Shenzhen Adventure Day 24
30 Jun 2015
With my back still in significant pain from the previous nights massages, it
was time for the South China Material City.
The South China Material City is an industrial region situated in Shenzhen where
you can go to get raw goods or materials in bulk quantity.
It’s basically a big outdoor mall where you can go into one of many vendors and find
anything you need, from gears to leather. Everyone is very hospitable and there were
offers of tea at some of the shops.
There was also some (very large) indoor malls, with lots of outlet priced goods:
There was also some more random stuff, like people drying spices on their shop fronts:
Or a seemingly abandoned amusement park:
You really could find anything there, from chemical supplies:
To raw plastics used for cables (something like $10/25 kg):
To clips:
That one is absurd – knives on carabiner clips to cut your rope?
Leathers:
Creepy Leathers:
Sewing machines – from new, to very old:
Tile carvers:
Papercraft store where you can get nice boxes made:
Lastly, there was cool finished good store with lots of cool electronics:
Overall, one of the funniest parts of the South China Material City was all the
samples people were willing to give for free. I got clips, bracelets, ropes,
fabrics, and many other things for free or very cheap. I almost made it into a
game to see if I could get something at every vendor I stopped by. The odd
thing is that when I contacted one of the suppliers to buy more bracelets (as
gifts for my return) they never got back to me!
Shenzhen Adventure Evening 23
29 Jun 2015
In the evening of the 23rd, we took a trip over to a local massage parlor.
Before you crack any jokes about what goes on in the massage parlor (yes, that
does still exist if you want to find it), that’s not why we went to the massage
parlor. We went to kick back Shenzhen Style! No photos of this trip, for better
or for worse.
The massage parlor is kind of like a rest and relaxation hotel. You can stay
there all night if you want to. When we showed up, we had to give the
receptionist passports in accordance with Chinese law for overnight stays.
When you get to the parlor, you split off by gender, and then you take a
shower.
Next, there’s a large public bath (naked!) where you can go to enjoy some cool
refreshing water, ice cold water, and steamy hot water.
Following your dip in the public bath, you get a robe and slippers and head on
over to the main massage area. Here, you get a huge comfy recliner chair, the
kind you could easily sleep in.
Then, a host comes over and offers you the menu, where you can order various
beverages (such as watermelon juice or beer) and massages. Bunnie was trying to
order a green tea for a very long time, because he kept on accidentally saying
road fork (they both sound like “lu cha”).
Typically you start off with some light treatments, such as a foot massage or,
if you’re feeling like it, an ear scrape (I wasn’t bold enough so I stuck to
the foot massage). Then, you can get a larger treatment if you like, your
choice of different varieties of back massage, such as a Traditional
Chinese Medicine or Thai Oil.
As I was told it was the most traditional was indeed the Traditional Chinese
Medicine Massage, I opted for that. A few minutes later, some doctors (of the
tcm variety) came to us and led us to the massage tables.
Now, I want to reserve my language somewhat, especially when it comes to
experiencing another culture, but FUCK EVERYTHING ABOUT THE TCM MASSAGE. It was
horrible, horrible pain for like an hour. The doctor systematically found every
pain and pressure point in my back and body and dug and jabbed them
mercilessly. As I squealed in pain, the doctor only laughed and prodded more.
If I had any secrets I’m sure he could have gotten me to reveal them.
For the rest of the week, my back was in pretty awful pain. I don’t think I’ll
be back for a TCM massage again, but I’d go back for a Thai Oil Massage (that’s
what you normally think of when you hear “massage”).
After the massage, there are some other facilities (such as ping pong) to hang
out and relax with, but I think I was too much in pain to want to take
advantage of that.
Overall, the massage parlor is a pretty good deal. For about 300RMB (around
~$50 USD) you get an overnight place to stay as well as massages and
entertainment. Would definitely recommend it for your trip out to Shenzhen, but
avoid the TCM massage.