All posts by nouyang

Uncategorized

Hardware sharing / versioning, recent startups

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A good number of hardware (well, electrical) online version control / sharing startups have come up recently.

  • http://www.evilmadscientist.com/article.php/visdiff – thoughts on smarter diff for EE
  • http://upverter.com/ 
    • http://upverter.com/tour/eda/
    • (version control. has good snapshot features for both board and bill of materials. has embeddable schematics. has nets. based around github, so social) 
    • “Online electronics design. Includes schematic diagrams, design hosting, parts library, and GitHub integration. Free for public open-source projects”
  • http://solderpad.com/ 
    • http://solderpad.com/tour
    • (version control and online ee viewing, board and schematic embedding. less of a social feel) 
    • “SolderPad is a place to share, discover and collaborate on electronic projects.” 
    • based off of github, so integrated
  • http://www.circuitbee.com/ — no updates since october 2011?
    • (for embedding boards/schematics)
    • “CircuitBee provides a platform for you to share live versions of your circuit schematics on your websites, blogs or forums.”
  • http://www.openhardwarehub.com/ 
    • (includes full hardware, not just ee, part sourcing) 
    • “The place to post and contribute to open-source hardware projects”

No doubt some form of open-source biology version control software will come into play soon too. But meanwhile the mechanical engineering side of things is looking a little bit neglected.

For online 3d model viewing, there are a few implementations, namely Thingiverse and 3dCADBrowser:
http://www.3dcadbrowser.com/preview.aspx?modelcode=3229 (has assemblies, it looks like) (no embedding)
http://www.thingiverse.com/thingiview:86385 (parts only, not assembled projects) (CAN be embedded!)
and a community around CAD:
http://grabcad.com/
another one, solidworks oriented:
http://www.3dcontentcentral.com/default.aspx

Tools / raw materials search: Maybe we should do our startup around this, for integrating into one of the hardware version control platforms. Octopart is doing it for EE; now lets get the meche side done too. Then we can really have full integrated open source products sharing+version control online, and then life will be awesome 🙂
If open hardware hub got popular enough (they allow “links” when you submit parts for your project), that would be cool.
[Edit 6 Dec 2011: I found a few search engines. See http://www.orangenarwhals.com/?p=157]

Some more research on the subject:
http://electronics.stackexchange.com/questions/8767/version-control-systems-for-hardware-projects basically says “use all the normal software version control systems” (none of which are made for visual diffing)
For some snark on circuitbee:
http://hardware.slashdot.org/story/11/07/26/183257/sharing-electronic-schematics — so yea, circuitbee is not too useful
and some more snark on upverter / circuitbee for not making the extra effort to be open source themselves:
http://dangerousprototypes.com/2011/09/21/editorial-upverter-another-closed-source-vampire-exploits-open-hardware-for-ventrue-capital-pr-and-profit/
and
http://hackaday.com/2011/09/14/upverter-its-like-github-for-hardware/
I think actually both circutibee and upverter are awesome and people are just being paranoid. -^-^- look at the long responses all the posts got from the founders o.o

to check out: another online circuits project:
http://code.google.com/p/webtronics/

Uncategorized

China Makerspaces Visit Planning

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I’m hoping to / planning on visiting Chinese makerspaces between end of term (12/19 for me, as I have not finals) and IAP (January 9).
[last updated: 11/24/2011]

http://hackerspaces.org/wiki/China
Shanghai

Shenzhen

  •   www.chaihuo.org, active as of november 2011
    • Saturdays, 14:00 – 16:30 (gcal sidebar)
    • ch.makerspace, g.com
  •   SZDIY (shenzhen diy lab) active as of today november
    • 聚会Every Thursday / 每周四 19:00～22:00
    • 答：Seeedstudio 是深圳创客空间（Chaihuo）的主要赞助商，Chaihuo与SZDIY目前达成协议在特定时间（每周四晚）免费提供聚会场地给SZDIY社区使用来举办固定聚会
    • szdiyadm, g.com
  • http://wikitravel.org/en/Shenzhen

Beijing

  •   http://bjmakerspace.com/ (both flamingoeda and gkfab have been subsumed by this, active as of october EDIT 11/24 active.)
    • meetings every Tuesday 20:00 to 22:00 (http://www.bjmakerspace.com/Event.html)
    • open every day (according to email correspondence 22 nov 2011)
    • http://space.flamingoeda.com/ (last update july)
    • GKFab (not alive?)
    • We have weekly meeting at Tuesday night, and workshops at weekend. The space is opened every day, and you may want send us a mail before you come so we can make sure there is some members in the space
    • bjmakerspace, g.com
  • yff — not sure if it’s actual makerspace looks corporate or spam. 

Guangzhou:

  • hackerspaces@gz (1 member?)
  • HTG (not active since 2010)
So looks like I should try to make Shanghai and Shenzhen, possibly Beijing although that’s covering a lot of ground in a week (mmm transportation costs). Guangzhou ones seem dead, which is a pity since that’s actually close to Shenzhen.

==
http://www.seeedstudio.com/blog/2011/10/16/first-open-hardware-gathering-in-china/
Ooh look! Someone I know is there! Star Simpson is apparently in China until January or so. And Maja Wichrowska (roomies shoutout!) is in Beijing for the semester. o.o Whoa. A lot of people I know are in China…
===
http://hackerspaces.org/wiki/Call-inJan 1st, 1600 EST
===
http://hackerspaces.org/wiki/Japan

  • kubotaa@tamabi.ac.jp (no response, dec 2011)
  • info@456.im (no response, dec 2011)
  • Tokyo hackerspace (contacted via form):
    • Tokyo HackerSpace has an open meeting every Tuesday night, from 7 PM. 
    • Unlike most other hackerspaces, our members have very little free time, and as such, the space is not in constant use. Our members have a key, and can come any time they like, but its hard to predict when that will be.
    • I would highly suggest that you join our google group and introduce yourself and your schedule there: http://groups.google.com/group/tokyohackerspace You’ll have a better chance at finding what everyone is up to, and when they can meet up.

http://hackerspaces.org/wiki/China
? None in Taiwan nor Korea.
===
Visas and Passport Renewal
Proxy Chinese Visa service: http://ask.metafilter.com/95095/Visa-service-recommendations e.g. http://china.visahq.com/ (also does passport, also well-designed site)
Emergency Passport-ness: http://travel.state.gov/passport/npic/schedule/schedule_852.html

Boston-specific:
I found a local Chinese company helping with visa application:
国际文化旅游公司
Cambridge
617-868-3096
最便宜的机票+最优质的服务$170 total /1 year multiple entry。 If you fill out the form. Sounds reasonable. close to what they charge here.It is close to T. ~5 walking from T station. 2 stops from harvard (outbound).Go to the web site, fill out the file and print out. take 1 2×2 picture, the passport valid for 6 month and blank page .
经纬旅游 Boston 617-426-3123
===
electronicky shanzhai 山寨
http://www.bunniestudios.com/blog/?p=284
and also awesome book:
http://craphound.com/ftw/download/ which is a fantastic romp around gaming culture, economics, and unions.
more on shanzhai
http://www.tigoe.net/blog/category/environment/295/#more-295
more on shenzhen http://www.evilmadscientist.com/article.php/shenzhen
the linked article is account-walled so here is the article http://www.strategy-business.com/article/09315?pg=all&tid=27782251

===
personal

1 Transportation FCU
 55 Broadway
Cambridge, MA 02142
Driving Directions
 Send to Phone		 ATM
Deposit-Taking
Surcharge-Free

1.16 mi

=== Options: personal tours. Or get MIT departmental backing (talk to Anne Hunter / Brandy Baker) for report publication, go in officially.

=== Oh hey look, someone wrote about MITERS in Chinese.
http://www.chaihuo.org/2011/10/19/%E5%88%9B%E5%AE%A2%E6%94%BB%E7%95%A5-%E4%BB%8Emaker-faire-%E5%88%B0mit-4/
“not the game, nor is it the job, just love” Thanks, google translate 🙂

===
update 2 dec 2011
according to David of shanghai’s xinchejian, There are current 4 in China. OnionCapsule in Hangzhou is the first student lead hackerspace in the China Academy of Fine Art by a group of new media art students. They have a public performance scheduled on Dec 24. If visiting hackerspaces is one of the goal of your trip, I’d suggest you visit them at this event. It’s crazy party and a lot of fun. 

Uncategorized

Lasers and such (aluminum business cards, wood and paper etching, edge-lit acrylic signs, thermoforming

I’m proud to say that I’ve sunk at least 40 man-hours of other’s people time into nyancat 🙂
(~150,000 views * 1 sec each / 3600 secs/hr  = 41.7 hours)

from 6:20am today (11/8/11) http://imgur.com/HnoAf

Makes me regret not thinking about watermarking my images (free publicity!). Thankfully, these are but brief lapses in my unfailing devotion to laziness.

Meanwhile, I’ve been exploring the joys of the lasercutter. I found some scrap wood sitting around the lasercutter and etched some of my best friend’s art (shout-out to Alice Chung! http://the-crowned.deviantart.com/)

I didn’t know what type of wood it was so I approximated:
material, lens, thickness, ppi, power, speed, description
aircraft plywood        2    1/8″        500    15%        80%        raster
aircraft plywood        2    .17        300    40%        3%        cut ~.17

I also want to make edge-lit signs and found some scrap acrylic. I checked out some real edge-lit signs, the ones used on the newer-style EXIT signs, looking straight up at them, and you can see the individual blips indicating a strip of LEDs. I thought they might have been using a fluorescent tube, which was my other though for lighting — strip out a discarded scanner’s tube and make a lamp ballast for it, then stick it over the acrylic. Todo: buy some nice strips of RGB LEDs. http://www.adafruit.com/blog/2009/09/22/making-an-edge-lit-acrylic-sign/ ~$7: http://ledshoppe.com/Product/led/LE5045.htm

this was .24” thick acrylic:
ACRYLIC (clear)        2    1/2″        500    80%        50        RASTER, 1/32 inch
ACRYLIC (clear)    (tinted)    2    1/4″        500    100%        1.4        cuts through 1/4” (.21”)

I’m sitting in the media lab shop right now helping a friend, Cathy Wu, make business cards for her imminent plane trip to some conference somewhere (_sigh_ smart people…). I was asleep in my room at 11pm when I heard a loud knocking, which turned out to be a hyper Cathy excited about cutting out business cards with the laser cutter 🙂 I had some anodized aluminum let over from the waterjet clock class / Kevin Rustagi, so there we go.
Giraffe design courtesy of Laura Shumaker, another awesome friend.

Settings used:
METAL ENGRAVE    2    n/a        400    50%        10        (Vector) Engraves into most sheet metals. (incl. anodized Al)to confirm: “my impression was that CO2 bleaches the dye in the anodize coating, while YAG actually penetrates the anodize to etch the aluminum”

The 100 watt lasercutter is definitely not awesome enough to cut this out (we tried full power really slow speed high ppi and it looked to have cut to the same depth as the etching). Maybe the BEAM lasercutter? We settled on using the power shears to cut it out.

I also learned that one can etch paper without burning it up!

Construction paper    2    0.01”        500    6%        80%        etch; — @100% speed, 7% min. to etch. @6%, 97% min. speed

thin cardstock — 1mm thick

People online seem to be getting lighter engravings, though, and I can’t figure that out! I tried all sorts of different settings for the construction paper and all I get is the burnt look. The cardstock I know for sure is white through and through and it also gives me this brown color. ??? I need to figure out this mystery:

http://www.epiloglaser.com/tl_paper.htm

Some very useful links:
Different materials at a glance, with examples (look at the dress under textiles! amazing)
http://lasercuttingshapes.com/page/materials
Everything ever about the Universal 100W CO2 laser and all the possible parameters:
http://www.inlay.com/cnc/laser/index.html
Supplier Acrylics, fluorescent (looks edge-lit without needing lighting):
http://www.usplastic.com/catalog/default.aspx?catid=442&parentcatid=443&clickid=searchresults

Ladyada’s examples page:
http://www.adafruit.com/laser/
With more details here:
http://www.ladyada.net/library/laser/settings.html
What people charge for some lasercutting services:
http://www.tree-fox.com/laser-engraved-and-cut-business-card-110.html
And pumpkins! Plastic ones though. We have real ones on hall that I was pondering…
http://www.advancedwj.com/gpage.html1.html

In other news, my surface mount soldering skills have vastly improved with a touch of patience. These all used the: tin one copper pad | tweezer solder the component onto that pad so that it’s straight | solder the other pad on | reflow the first pad. This seemed tedious to me in the past, but it actually goes pretty quickly and helps me place my components correctly (darn lack of silkscreening) since I’ll go through and tin one pad for all the components.

I also printed tiny-to-be-painted-and-turned-into-earring nyancat:

This is the 3d printer:

Meanwhile in 2.008 we thermoformed for the first time. Here’s the thermoform machine:

turned out pretty well, almost none of the webbing we were afraid of.

The machine is super-straightforward to use. I’ll write it down sometime.

then you use the punch/die to cut out the part you want
some of the injection molded parts. The metal shim actually really affects the shrinking of the part, so our ring and body parts didn’t press-fit together (both used a 3% shrinkage estimate). To be fixed!

Oh, and my food-grade silicone arrived. $17 for a lb off of amazon.

And I shopbot’d a new foam positive. But the silicone negative mold turned out fuzzy :/ with bits of construction foam attached:

Make lots of sacrificial cake until all the foam is melted away? I’m not sure. This silicone will stand up to 400F while the foam melts pretty easily (eg at the hint of a heat gun).

My vending machine coils arrived off of ebay. They definitely look like something I could make by hand.

Also, I learned that ftdi breakout boards are indeed substitutes for ftdi cables. See here for a cool look at what you can do with ftdi:
http://hackaday.com/2009/09/22/introduction-to-ftdi-bitbang-mode/
and some more about ftdi (e.g. vs. avr programmer):
http://www.ladyada.net/learn/breakoutplus/ftdifriend.html

Oh, for 6.131, my final project, some research:
Our normal 6.131 555 pwm generator will not work here. Servo “PWM” signals are very specific — 2 to 4% duty cycle, 20msec period.

http://www.seattlerobotics.org/encoder/200106/16csscnt.htm

use a servo tester then:
http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?idProduct=17143 $5
or implement the circuit:
http://www.societyofrobots.com/robotforum/index.php?topic=13833.0

Also, turns out you can totally do diy soldermask (to mask the circuit traces you don’t want to accidentally solder to):
http://retromaster.wordpress.com/pcb-making/ via http://electronics.stackexchange.com/questions/15792/diy-solder-mask-toner-transfer
and a product from seeedstudio:
http://www.seeedstudio.com/wiki/index.php?title=Solder_Mask_Ink