The Hackerfarm Taobao Shuttle

At hackerfarm we have a limited shuttle service where we consolidate taobao orders and have them shipped from Shenzhen via our buyer out there. This service is not currently available to individuals outside hackerfarm, but the general information on purchasing from taobao might be of use.

There are a few restrictions: Firstly, nothing obviously dangerous. No un-installed batteries of any kind, no products containing large Li-ion batteries (possibly any li-ion so please check first). Any kind of liquid can not be shipped. This includes products containing liquids. All these items need to be sent via more extensive services, which we avoid on the shuttle.

Orders go out on the 20th. To submit orders individuals need to put them in out standard spreadsheet layout (shown below). The spreadsheet should be updated to show the current CNY->USD exchange rate, Akiba can provide a current version of the template. It also shows the reshipper fee (currently 20%) for your reference. For each item you need to add a taobao link, quantity, unit cost, and any notes required to specify the exact item type.


For a up to date spreadsheet template, contact Akiba.

All sheets need to be submitted by 11:59pm on the 20th.

Akiba consolidates these sheets and sends them out to our shipper (and distributes a copy for reference, and to check for any errors). The shipper will then add domestic shipping to the total and sends Akiba an updated sheet. This gets re-circulated, but sign off is not required for the order to proceed. However if there are any clear red flags let Akiba know.

Orders are now submitted and everything gets consolidated. At this point you may discover that some items are not available. In general these will just get dropped from the shuttle. The package is then shipped to Akiba for local distribution. In general it will take 2 to 3 weeks for orders to arrive.

When the package is received, Akiba co-ordinates local distribution. Akiba also receives payment at this point for each individual’s part of the order (and pays the shipper). International shipping is split between individuals based on weight, Akiba also manages to calculation of this. It’s unfortunately not possible to calculate this in advance, so you need to agree to a degree of uncertainty here.

TSOP48 ZIF Socket Footprint


tsop48zifYou can pick up these neat TSOP48 ZIF sockets on eBay. I’ve been using them for a TSOP48 NAND flash reader which will eventually be available on my shop.

The footprint is kind of fiddly. And I’ve attached the second rev for Kicad below. I’ve not yet tested this version but r1 worked well enough that this is likely ok. In r1 the pins needed moving out ~0.5mm (socket fit, but it was a squeeze) and I need to remove the mechanical mounts as they were off by about 1mm.


Kicad footprint: tsop48zif-kicad_mod


A Note on Collaborations

This note is on collaborations where some overlap exists between technical development, artistic elements, and user requirements. The focus is on hardware collaborations, where no money changes hands. These notes reflect my personal experience, and observations of collaborations to date.

The first point, is that if you have a strong desire to complete the project rather than engage in open ended discussions it’s important to get explicit agreement from individuals engaged in the collaboration, and on any external deadlines.

Implicitly, it will be up to the individual who proposes the collaboration to manage the project. The ideal scenario is if a single individual can create the initial proof of concept (others offer advice, suggest easy to use parts).

Hardware collaborations generally in my experience take at least 3 revisions to get to a reasonable proof of concept.

In most cases you should budget at least a month per iteration, regardless of complexity. This is because unless you are funded you’ll be acquiring PCBs and other parts from China (this is x5 to x10 cheaper). Shipping these parts takes on average a month.

Specific Guidance

Early in a project, it’s useful to get answers to specific questions, these vary depending on the project, but where appropriate it’s useful to get answer to the following.

General Questions

  • Are there any deadlines involved (for grants etc)?
  • What environment will the project be in (indoors? Outdoors? Vacuum?)
  • What is the power source (battery, mains)?

Sensor projects

  • What are you measuring?
  • With what accuracy/resolution?
  • How long will the sensor be acquiring data unattended?
  • Where is data stored? Or how is it transmitted?
  • Data visualization requirements?

Motion projects

  • With what resolution/accuracy do you need to move the actuator? (nm,um,mm,cm?)
  • Over what distance do you need to move the actuator (um,mm,cm)?
  • Linear motion? Rotation?
  • If possible, provide a sketch of the system, with approximate dimensions.
  • If moving a static load, what weight does the actuator need to move?

Imaging projects

  • If optical imaging, what wavelengths are you interested in (visible light only?)?
  • Resolution,accuracy,noise levels, quantum efficiency requirements?
  • Will image stitching or computational intensive post-processing be required Do you have access to compute?
  • Do you have access to adequate image hosting facilities?

Fabricating oval through-hole pads


A friend has been trying to make slot like through-hole pads. These are the kinds of pads you’d use for the strain-relief pads on a USB connector etc.

I don’t use these, but I should and probably will on my next board. My friend had ran into fabrication issues using the oval drill shape in Kicad. Investigating this I found that the oval drill don’t seem to get written to the¬†excellon drill files by Kicad. So there’s likely no way that they’d get fabbed (my friend uses the OSHPark Kicad import, but I’m guessing this just generates the drill files using Kicad anyway).

From what I understand of the OSHPark documentation on the subject. These holes should be marked as internal routing. In Kicad this is specified in the Edge.Cuts layer. The image above show an example where I’ve marked the routing around the hole. I believe this /should/ be fabricated correctly, but need to try it out. The OSHPark docs contain the following image (which they say /should/ work and will result in a plated hole:

unsupported-slot-calloutHowever, they actually recommend in that document (linked above), that you replace these kinds of features with regular, larger, holes.