

Building a Keyboard: Part 2 - flapjack
http://blog.fsck.com/2012/12/building-a-keyboard-part-2.html

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sbierwagen
\- Poking holes in a plastic project box with a soldering iron isn't something
you'd do in production, but it's fairly common when screwing around with a
hobbyist project.

\- Twisted-pair cable either requires either grounding one wire in the pair
(in 100baseT) or fancy differential-signalling tricks. (in 1000baseT or HDMI)

\- Sounds like the biggest problem was solder joint failure as a result of
inadequate strain relief. In satellite design, where repair is, of course,
impossible; the rule is to never use a solder joint as a mechanical
connection. The component is secured to the frame, and the wire coming off the
component is separately secured.

If you're not building a satellite, the method of accomplishing this is
usually hot-glue, copious amounts of it, on everything. (As seen in cheap
hand-assembled electronics. Expensive electronics are robot-assembled and use
SMD components, which usually don't need strain relief unless you're doing
something really exciting.)

~~~
obrajesse
Thanks!

In a bunch of the cases, the problem was "hysterically bad solder joints." It
wasn't so much that the joints would fail when put under pressure as that
they'd fail when you looked at them funny.

~~~
Kliment
Please don't melt holes into that material with a soldering iron. The plastic
you are using appears to be nylon, and nylon releases highly toxic fumes when
melted. In addition to the nasty smell, there are some things in there that
can kill you before you notice them. I highly recommend using a drill and a
small file to make access holes like that. It's faster, safer, and looks
better in the end.

~~~
obrajesse
I'd love a citation on "some things in there that can kill you before you
notice them" to update the original post with - A quick websearch doesn't find
anything more than "it's carcinogenic" and the material safety data sheet
doesn't call it out. ([http://www.shapeways.com/rrstatic/material_docs/msds-
strongf...](http://www.shapeways.com/rrstatic/material_docs/msds-
strongflex.pdf))

~~~
Kliment
Number 5 in that MSDS contains carbon monoxide which will kill you in small
quantities. The "other toxic products" include HCN (hydrogen cyanide) which
will kill you before you can detect it. It is produced in very small amount,
but very small amounts of it are toxic. A reply to your post which is dead for
some reason posted [http://www.greyops.net/2010/05/advisory-burning-nylon-
thread...](http://www.greyops.net/2010/05/advisory-burning-nylon-threads.html)
which has a couple more compounds that are released in low concentrations when
Nylon burns.

There is a massive argument in the 3d printing community about whether Nylon
is safe to print with. I would use it only in an industrial/laboratory setting
with decent fume extraction and filtering and safety procedures (like
Shapeways has). There is a dangerous asshole who is actually selling nylon
filament for printing and telling people it's safe. He has performed some
tests with an HCN detector with very questionable methodology and is now
making a lot of noise about how safe it is. This is why I felt compelled to
make some noise about how incredibly dangerous it can be to process it in a
home setting. Note that unless you subject it to very high temperatures it's
not going to decompose.

------
joebadmo
There's a personal balance point between customization and portability e.g.
how much to customize Vim or rely on shell/git aliases. These kinds of
customizations can improve your personal workstation, at the cost of
incompatibility with other people's machines and the spin-up time for new
machines.

For keyboards, having to sometimes use other people's machines as well as
frequently switching between my desktop and laptop means that, while tempting,
this level of customization is too far for me. The sweet spot for me is a high
quality mechanical switch (-style) keyboard: Topre's Realforce.

------
pkamb
An interesting wrinkle in these "column" keyboards (where Q-A-Z are lined up
in a column rather than staggered) is that I self-corrected for this
deficiency years ago; my left pinky hits Q-A-Shift, ring finger hits W-S-Z,
middle hits E-D-X etc.

The W-S-Z fingering leads to a nice curve that mostly follows the movement of
your finger, just like what you get on the right side of the keyboard (U-J-M,
etc).

I don't know how folks type Q-A-Z with their little finger. It causes
immediate hand pain to curl my fingers inward/perpendicular to hit Z, X, C,
and V.

I imagine this method was only taught in the first place thanks to clueless
typing teachers who thought "first keys on the left = first left finger",
ergonomics be damned. Does anyone else type "Z" with their ring finger?

~~~
obrajesse
Actually, I do. That's part of what has made this design challenging for me.
The next thing I build will have a ...somewhat different layout.

------
shabble
Part 1 (from yesterday): <http://news.ycombinator.com/item?id=4893457>

------
thinker
What!? How do you not like Modern Family. I think you need to give it another
chance.

~~~
obrajesse
I know that many people love it. It...just doesn't work for me. Ah well.

------
kurjam
Reading this made me feel like building my own keyboard. Maybe use a little
dvorak on it... Thanks!

~~~
grimborg
Me too! It seems like it's gonna be hard to obtain keycaps and shells,
though..

~~~
kurjam
Yeah. After butting some hours of research into this I'm afraid that would be
a little too big project for me to start with currently. So from this site (
<http://www.fentek-ind.com/FootPedal.htm#afs3usb> ) I found a little idea
which i just might try out. But instead of leg switches, I thought about
adding a new modifier(s) under/near my palm rests (pressure switches I guess,
but needs some testing first, what feels comfortable) to get brackets, colons,
<> and other daily signs from the home row.

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gambiting
He's really lucky he wasn't arrested by the TSA, like that guy who had a
custom-made watch and got arrested for "possessing all elements needed to make
bomb". Namely - a few wires and a battery. He was arrested and put under $10k
bail. A Keyboard that was opened and soldered on the inside? That could earn
you some nice jail time in the Uncle Sam's land of freedom.

Edit: But yeah, the project looks really cool, something that each one of us
uses every day and yet is so complicated internally. Well done.

~~~
obrajesse
Part of the trick is that I was aware of what I had with me and was careful to
actually open its case so the TSA agents could easily see what it was. I was
friendly and engaged and prepared to talk their ears off about ergonomics ;)

Flying out of DCA a week later, the TSA agent was astonished that I wasn't
_selling_ keyboards -- "People will buy anything. You should make some money
on that shit."

Transiting Narita and flying out of Taipei a week after that, I just put it
through the X-Ray. Nobody said a thing.

