Here you'll find an assorted mix of content from yours truly. I post about a lot
of things, but primarily
Shenzhen Adventure Day 14
20 Jun 2015
We were lucky enough to overlap our stay with the Shenzhen Maker Faire!


There were a lot of drones…

I even ran into some friends!
Lizhou Sha MIT ‘18
Deb Weinswig, my cousin!
We finished off the day at the Hackaday pizza party.
What struck me most is that we were like an hour out of the city by subway but it still looked like this:

The amount of construction in the region is insane.
Shenzhen Adventure Day 13
19 Jun 2015
Watering trucks! Saw this during a night out. They go around and spray
down all the fancy greenery.


Shenzhen Adventure Day 12
18 Jun 2015
Inside the King Kredie Engineering Query room
On Day 9 I mentioned that we had submitted our boards for Engineering Queries,
but I didn’t quite explain what those are.
When you’re working with a good manufacturer, they don’t just blindly produce
what you tell them, they will go through and verify certain properties of the
design to make sure it will come out as expected, or even tell you ways you can
save costs that you may not have thought of. This is because:
- they want your future business
- they’re just good people
- they don’t make more money on the more expensive process
3 can happen because a different process may have no different labor cost, but
just a material cost which they don’t mark up. This is an important point to
keep in mind when working with various manufacturers – they will pass savings
on to you if possible!
Shenzhen Adventure Day 12
18 Jun 2015
While we were doing the Engineering Query at King Kredie, we also got a
special bonus tour: Flex PCB Manufacturing.
Flex PCB is kind of the future – as devices get smaller, a thick-old-green PCB is
no longer practical unless it is also a structural element. Flex PCB’s, traditionally used
more often as a custom connector, can be populated with components as well so are a really cool
technique to experiment with.
The process is pretty different from traditional PCB etching.
You start with a big roll of copper foil.

Punch out a pattern using a big press.

The die looks like this:

Then you laminate it. The laminate sheet has also been punch cut appropriately.
An iron is used to bond the plastic laminate to the copper/backing laminate.
Then you (optionally) silkscreen print on
Alignment is not critical here.
Finished product:
This flexpcb has a stiff copper trace inside of it as well for rigidity on that axis
Later on, these will need to be cut out/depanelized.
Shenzhen Adventure Day 11
17 Jun 2015

The printing press guys were really the best – so good, they get three posts
for one day!
Following our visit, they taught us how to do – and appreciate – the
traditional tea ceremony.
To make the tea ceremony, first you use hot water in
a little basin to wash out all of the tea cups. Then, you fill the teapot with
tealeaves, and use the basin (with fresh water) to pour hot water over the
leaves. You stir by gently shaking the tea for 30 seconds, and then pour out
the water. The first wash is thrown out traditionally to make sure the leaves
are clean. Then, you repeat and let steep for a few minutes. You drink all the
tea, and then repeat over multiple washes of the tea.
The tea they were using was incredibly good; probably the best I’ve ever had.
When we asked where it came from, they told us their friend grew it!
A parting gift
The week we were set to leave Shenzhen, the guys from the printing press sent
us a big box of the tea we made the ceremony with. I’ve shared my stash of the
tea with friends and family, sharing my stories from Shenzhen, especially the
generosity of everyone who made us so welcome there!