Anatomy of a Scam: the tale of the £40 3D printer.

Posted on 2015-10-05 in misc

Aliexpress Screenshot

When i saw this, I thought "£40 for a 3d printer?  Including UPS shipping? This is too good to be true!"

Though thinking about it a bit more, I couldn't think of any way they could get away with the money.  Aliexpress offers full buyer protection if you buy through alipay, and money is held in escrow.  So I bought a couple to see what the dealio is. If it does arrive and its shit, just the motors would cost more then £40 to buy, and I can definitely reuse them.  I figured going into this paranoid, I might just about be able to figure it out before they run away with my money.

This morning, I got shipping confirmation, with a china post shipping code. "Wow, maybe its not a scam?" I thought. Then I received this message:

hi. friend. Because you choose courier suspended. We send you the goods by China Post Air Parcel. Give you cause delays receive the package, so we give you $15 in compensation. You may submit disputes. A partial refund of $15 agreement. We give you a refund in a timely manner. Thank you

Ok, yeah, thats a bit odd.  This is the penny dropping.

The way AliExpress works, you can open a dispute on any order for either the full, or part of the purchase price.  If the seller agrees, the refund is paid out to you right away.  But if I open a dispute for the shipping, maybe I lose the ability to open a dispute for the remainder if the item doesn't arrive? The FAQs were unclear, so I set off to AliExpress customer support:

If I open a dispute for a partial refund (for the shipping), can I then open another dispute later if the item does not arrive

No, if the dispute has been agreed the seller with partial refund, the remaining payment will be release to the seller automatically

With this, I highly suggest to please ask a full refund instead.

So there it is.  Beautiful in its simplicity.  You ask for a dispute for the shipping charges, get your £8 shipping back, and lose the ability to claim back your £32 for the rest the item when it doesnt arrive.  Since I have 40 days of purchase protection remaining, I'm going to hold off claiming a full refund for a couple of weeks, and I'll update here if I turn out to be wrong and something does arrive!


Another message is being sent to those of us who have ignored the first message, or replied that the refund is not necessary:

Friends. Goods are in transit. Do not worry. We give you a refund of compensation today. Tomorrow no longer compensate, please submit the dispute in a timely manner, thank you

Ahh, a time limit! Best get the refund quick, otherwise they wont offer it anymore! I've received this second message, as have others. I'm guessing it wont be long until aliexpress close their account, so they've gotta try and get as much cash out asap.


Just got an email from aliexpress:

Your order --REDACTED-- has been frozen due to suspicious seller activity.

We have suspended this seller’s account because we detected unsafe trading activities. All of your pending orders with this seller have been frozen for your security.

We have asked this supplier to provide supporting evidence, such as shipping documents and qualification certificates. If the supplier is unable to provide the evidence or if the evidence is insufficient, we will close the order and process the refund for you within 5 business days (In case of certain circumstance, the processing period may be extended).

We apologize for this inconvenience. At AliExpress we are committed to ensuring you enjoy a safe shopping experience. We will continue striving to improve. Your understanding and cooperation are highly appreciated, if you have any question or suggestion, please click here

Your understanding and cooperation are highly appreciated.


AliExpress Trade Security Department

I'm fairly unsurprised by this, hopefully the refund will be forthcoming fairly quickly.

Final Update

Your Order No:-REDACTED- has been closed because the supplier did not provide necessary evidence. The payment will be refunded to you within 7-10 working days.

AliExpress strives to continuously improve our trading environment. Thank you for your understanding and continued support.


AliExpress Trade  Security Department

And its over. This experience has massively reaffirmed my confidence in aliexpress' customer services and payment systems. Other sales websites should take notice!

Minimus Pin Functions v1.2

Posted on 2012-09-14 in misc

Minimus Pin Layout v1.2

Got fed up of not having the interrupt identifiers on the original minimus pinout i made, so here is version 1.1 with interrupt numbers labelled!

Stay tuned for a pinout of the Minimus 32K, as UK hackspacers have just bought over 300 of them to play with!

UPDATE: I have checked the atmega32u2 datasheet, and all pins and functions are the same as the at90usb162, so the above sheet will work for both.  Yay!

UPDATE: Oops, had the LED pins switched. fixed in v1.2

Minimus Pin Functions

Posted on 2012-02-13 in misc

Minimus Pin Functions

Whipped up this quick cheat sheet with all the different functions each minimus pin can perform.

Speak and Spell - Keyboard Matrix

Posted on 2011-01-27 in misc

Speak and Spell

Tonight i spent some time at Hackspace Manchester reverse engineering the keyboard matrix on our speak and spell, in preparation for hooking it up to an MBED.  Since nobody else has released this information (as far as i can tell), here is the pinout:

pin 3 4 5 6 7 8 9 10
1 u k off a f ? p z
2 v l go b g & q `
11 w m < c h ??? r #
12 x n " d i :) s /
13 y o _ e j on t return

This means that when the 'off' button is pressed, for example, pin 1 and pin 5 will be connected together.

To read a matrix keyboard like this, we write some code that steps through the 'down' set of pins (1, 2, 11, 12, 13), holding them low one at a time, then checks each of the other pins (3-10) to see if anything is being held low. If so, we perform a lookup on the table above.

AVR GCC Bit Manipulation Macros

Posted on 2008-07-27 in misc

These are some macros i originally found on avrfreaks for bit manipulation. I have posted them here in case they are useful to anyone.

#define bit_get(p,m) ((p) & (m))
#define bit_set(p,m) ((p) |= (m))
#define bit_clear(p,m) ((p) &= \~(m))
#define bit_flip(p,m) ((p) \^= (m))
#define bit_write(c,p,m) (c ? bit_set(p,m) : bit_clear(p,m))
#define BIT(x) (0x01 << (x))
#define LONGBIT(x) ((unsigned long)0x00000001 << (x))