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Central MN, USA
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Many of us, including me, purchase parts from ebay but have I been living in a hole or not?! Here is some relay boards someone bought on ebay:

http://www.ebay.com/itm/5V-1-2-4-8-Channel-Electronic-Relay-Module-For-Arduino-ARM-PIC-AVR-DSP-TTL-/300749445346?pt=LH_DefaultDomain_0&var=&hash=item46061058e2

I thought each relay is like $2.5 but their dual relay model is $2.5 free shipping all assembled?! 8 channel is just over $9.

I'm not associated with this seller but just trying to share information. I have a relay board design and made a few for my own use but I'll stop doing that now and buy some of these instead.
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I bought a two channel model awhile back but not sure if it was this seller or not. I think I paid around $4 for it, but I can't recall and my e-bay purchase history only goes back 90 days. Anyway when it arrived I checked it out and was very pleased with it's build quality and functionality, and yes it would be kind of dumb to build a version at these prices unless one just wanted to gain the experience of doing so.

There does seem to be some that are very much against buying directly from these Asian E-bay sellers and like to question the quality and intergaty of the sellers. I have been a buyer on E-bay for close to a decade now and have found most of the high volume Asian sellers to be very protective of their positive feedback rating and in a couple of transactions that shipped the wrong product were more then willing to reship the correct item and let me keep the one shipped in error.

My only two issues with most of them is:

1. Stuff is almost never documented at all, if the E-bay ad doesn't tell you everything you wish or need to know about the item, don't expect to get any further information with the shipment. E-bay seller Sure electronic is one exception as they do have pretty good downloadable documentation on most or at least a lot of their stuff.

2. The 'free shipment' must be a result of some kind of State issued credit or otherwise subsidised in some way? I've bought stuff for less then the cost of the postage on the item received? Pretty unfair advantage and not sure that will always remain a policy (free shipment)

Lefty
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Shipping can be so cheap as they collect so many articles until they have a very big sea-container full of stuff. In such a container fit ~80.000 items .

- http://www.schumachercargo.com/shipping-container-sizes.html -

biggest = 13.6 x 2.7 x 2.3 meter ~~ 85 m3 == 85.000.000 cm3
A typical box for electronics is 5x10x20 cm = 1000cm3
so there fit 85.000 packets in a container.

If you pay 10 cents per item (less than 5% of the average price) for transport that means you have $8000+ for transport of one container.

How many containers on a big ship ==> 1000? 

http://www.forwardinglogistics.com/sea-freight.html?gclid=CN_q7JaLorQCFSTLtAod5S0ABQ

So that makes in the order of  $10M for one tour (OK it uses lots of petrol too)

This is a first order estimate of free shipping (now you may shoot smiley-wink

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Rob Tillaart

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my e-bay purchase history only goes back 90 days.

Don't you just hate that? I try to keep a record of what I buy on a spread sheet.


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yes it would be kind of dumb to build a version at these prices unless one just wanted to gain the experience of doing so.
Experience gain, check!
Making more of my own relay design, uncheck!

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2. The 'free shipment' must be a result of some kind of State issued credit or otherwise subsidised in some way? I've bought stuff for less then the cost of the postage on the item received? Pretty unfair advantage and not sure that will always remain a policy (free shipment)
Most of the stuff I purchased off ebay from Chinese sellers ship out of Hongkong. It's a free port so shipping is very cheap. Sometimes I purchase from sellers shipping from Shanghai and I can see their shipping charges are quite a bit! I'm not sure about State ever caring for small businesses this much to offer subsidy. It's more or less the other way around. If you are foreign investor, you can invest and make money without paying tax for a number of years and still pay low tax afterwards. Some notorious Korean companies take advantage of this so they would set up a factory and produce for 3-5 years and when they're supposed to pay tax, they close the factory and open it elsewhere to get the fresh 3-5 year tax-free periods again. The workers from the factory they close are without jobs. In China, if you are a small business, nobody cares about you since there's not enough profit in the business smiley-wink
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This is a first order estimate of free shipping (now you may shoot

My small packages always seem to show evidence on the outside package as using air service. I always get the stuff pretty reliably in 10-11 days here on the US west coast, which I think would take much longer if sent via sea-land trailer on a ship from China?

Lefty
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I like the idea of a first order estimate except for all the 3-digits are separated by dots instead of comma  smiley-wink

We are all very much ripped off by shipping companies worldwide. Even for shipping across boarder between USA and Canada, shipping USA-Canada seems cheaper than the other way around. There's a huge tax and profit margin, is there not?
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are separated by dots instead of comma
oops, (dutch style is reversed - at least in numbers smiley-wink

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There's a huge tax and profit margin, is there not?
Yep, but it's so easy

Ask people from Brazil - 100% import taxes on anything! - no wonder it is a booming economy !
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Rob Tillaart

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Well, I think I am well known for my ebay bottom feeding, and have noticed (and posted about) this many times too.  However, in my case, the I get the deals I do because I am not "shopping" for items in the normal way.  I sometimes get items at what has to be far below cost to produce.  I have found that some vendors blow some items out simply to get positive feedback points.  That's amazing to me, but hey, I am willing to give good review for a great deal, no problem!

I tend to end up with stretches of time I need to kill, so it's not a problem (and somewhat zenlike) to troll thousands of auctions looking for the un-noticed gems among the gravel.  Yesterday I got a tube of TWENTY 40-pin AVR's (4414's) from a vendor in Colorado for seven dollars, it's another seven to ship.  Uncommon to get deals like that domestically, but in this case, I think the outfit is a clearinghouse for components bulk-purchased from defunct businesses.
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However, in my case, the I get the deals I do because I am not "shopping" for items in the normal way.  I sometimes get items at what has to be far below cost to produce.

I have to watch myself as I will impulse buy just based on the 'wow how can they sell that thing at that price'. Latest example was a little more cost then I usually impulse at but I couldn't resist this very versitle 20 watt buck switching regulator with adjustable current limiting and voltag/current output display. The thing arrived this morning in the mail and it's all they said it is and I've been playing and turning pots and having a great time with it. Can anyone say they could built this thing for $12?

http://www.ebay.com/itm/170929163705?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649




* H549-3.jpg (88.59 KB, 600x600 - viewed 13 times.)

* H549-4.jpg (105.21 KB, 600x600 - viewed 11 times.)
« Last Edit: December 17, 2012, 06:18:41 pm by retrolefty » Logged

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However, in my case, the I get the deals I do because I am not "shopping" for items in the normal way.  I sometimes get items at what has to be far below cost to produce.

I have to watch myself as I will impulse buy just based on the 'wow how can they sell that thing at that price'. Latest example was a little more cost then I usually impulse at but I couldn't resist this very versitle 20 watt buck switching regulator with adjustable current limiting and voltag/current output display. The thing arrived this morning in the mail and it's all they said it is and I've been playing and turning pots and having a great time with it. Can anyone say they could built this thing for $12?

http://www.ebay.com/itm/170929163705?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649




Wow, that's a great deal! I think I need a couple of those. I have several higher voltage power bricks from days past that I could recycle.
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I bought this one:

http://www.ebay.com/itm/New-5V-8-Channel-Relay-Module-Board-for-Arduino-PIC-AVR-MCU-DSP-ARM-Electronic-/170745298865?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item27c1367fb1 for under $10

was delivered to UK within 10 days. I also found it was great build quality and used in a project with 100% success (so far).

http://gampageek.blogspot.co.uk/2012/12/remote-controlled-eight-relay-board_10.html
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Craig Turner, blog: http://gampageek.blogspot.co.uk/ It helps with my learning if I write things down, esp. for others to follow (constructive comments welcomed to improve)

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that's a great deal!

Yes, particularly when you look at the coil.
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I bought the same model...

Thing about the 2 relay with the 2 optoisolators, is they trigger on a LOW signal, most of the 4+ relays trigger on a HIGH, it's not a big deal, but annoying.
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