My first Eagle schematic and board

lilimike said:

yes that is for sure, I was referring to a small prototype in a quantity of no more than 3.
Actually I was wondering how these people can manage to get this cheap to put together a bunch of PCBs and send them to a Fab house like yours!

Why can't a Fab house do the same directly?
By the way you have good prices, when I get into quantities you will see me drop by.


Mike

Click to expand...

Thanks a lot, We have considered this issue. But spending too much shipping cost. If no local transfer station, the price we can not do.

We can imagine that, if there is a transit point for the UK, then 100pcs PCB via FedEX shipped to the UK, the shipping cost is not expensive compared with 1pcs PCB many. Local redistribution, just to pay domestic postage rates.
Another reason is that panel, they send multiple PCBs together in a large board, and then they cut them when the large board back to the UK, this can also be cost savings.

I understand what you are saying but what I don't understand is:
if some people can charge less than half of what you charge (small qty) fill up a board and send it your way, then get it back and ship to everyone and still make money, if they can do it why can't you?

Please don't take this as criticism, I am just curious as to why!

Mike

Hi Mike, I can not explain it in Chinese, let alone English. I am afraid I can only say that this is an industry pricing model. I think if a factory with 300 workers to do that, perhaps it is unable to pay wages. But for one person small site, is actually quite a good deal.

The reason companies can aggregate a number of small boards is because they are typically ordering one very large board at the end of it, thus attracting much lower prices from a manufacturer. However, this requires considerable work from the "middle man" and that is why it is a fundamentally different business type/model than a PCB manufacturer.

Of the many snags I can think of, here are a few:

• actually getting enough volume to fill a big panel without ridiculous lead times (industry seems to be 5-7 days typically)
• ensuring the most efficient placement of lots of little boards one on large panel instead of just manufacturing what you are given on a standard (e.g. 100x160mm) board
• getting multiple gerbers (potentially with slightly differing formats) from lots of customers onto one big board - software for this is not cheap
• posting up all the final boards to many people rather than a single customer

Some of this such as the DRC can be automated, but there is a lot of human work involved still. It is this specialist human work that costs the $$.

The benefit for the PCB manufacturer with large boards is that they only have to feed one set of information into the equipment (photo plotters, CNC drilling/milling machines etc) for a large board. If you simply order 2 or 3 small boards (e.g. 100x160mm) from a manufacturer then this is a very small run with all the same setup requirements and hence prices per square inch will inevitably be much higher.

I think the issue of filling panels would be enough to break this business model for most PCB manufacturers. Most amateurs don't mind waiting a variable amount of time in order to pay low prices. Engineering businesses don't work the same way.

I assume BatchPCB are able to offer their service as they can fill panels with boards to sell on Sparkfun (helped by a huge potential customer US base and a reputable existing store).

I'd love to see something similar in the UK (to avoid all that globe hopping in planes and reduce the lead time) but I do not know if it would attract enough customers.

Yes I pretty much get the picture, thanks for the explanations.

Mike

I would say that each PCB supplier has its own market position.
I have been discussing a simple comparison.

When 1 pcs of PCB



When 4 pcs of PCBs

The boards came back and I'm pleased. The quality of the board looks good and i think they have been manufactured well. One of the IC's has pads which aren't that small on my computer and the traces look a bit squashed in one or two places, but nothing to quibble about. I ended up getting 4 of them with an area of 1dm (3 inches square) for £48 ($70) which includes tax and delivery, so the price is reasonable. They shipped a day late, it was sent first class, had to be signed for and came in a very sturdy box.

The major problems I know about revolve around the transformer. I made the board up on stripboard and didn't test it with the load. I realised this after I'd ordered, so essentially I was thinking i'd get 10Vpp into the transformer primary and it'll be closer to 6Vpp. As I need 10Vpp I will have to see if I can get another transformer with lower primary impedance. The other problem is that the transformer doesn't fit on the board, so it will have to stay off for testing. I have almost finished making up the board and so I don't know if it will work or not. I haven't put the momentary switch on, that needs the batteries going through it and I haven't quite figured out the best way of going about that.

General thoughts are, the traces are wide enough but they could have been much bigger, the board could have been smaller, I put 2 vias into the ground plane which seem not to have been connected to it like i'd have prefered. I should round off traces more.

Feel free to comment and thanks for the input.

Antknee,

You have no silkscreen and no soldermask, I guess it does the job for a prototype.
I have placed an order at the place I had suggested in post #35 and I am expecting it Monday or Tuesday I have 4.47 inch² per board and I will get 3 boards. They charged me under $23 (tax and shipping included) I will post the result when I get it.

Mike

Hi lilimike,

That is an excellent price, I looked at the website and it is american so I assumed I'd be paying shipping of $20-30 to get the board to the UK, I could be wrong and will investigate further. I will add silkscreen and soldermask to the final build, I printed off a copy of the board from Eagle and used that to place parts.

Thanks,

Antknee.

I got by board back from DorkbotPDX and I am really pleased with it so I just found my future resource for prototypes.
I got 3 copies of this board, it's around 4.5² In delivered in a little more than a week for under $23.


I just wish my camera was as good quality as yours because the board looks much better in person!

Mike

That board does look good! I saw it and it reminded me of constellations in the night sky, what is it? That is a good price, I checked the website a few days ago and they don't ordinarily ship to the UK, I'd have to ask and get the shipping price. I sent another order to PCB-Pool last night, my board is around the same size as yours and I'll get 3 copies for around $75 including everything.

If they ship (like in my case) by USPS first class I don't think it will cost anything other than a small delay. I am in Canada and it took 6 days to get here from the time DorkbotPDX shipped it. Its going by plane so I don't see why it should take more than an extra day.

Mike

This service is really very cost-effective for small areas of the board.

The version more compact than the first

how can i find the variable resistor's symbol in the libraries ?
thanks alot

WELCOME TO ETO

under resistor,
you get resistor-trim, open that list and select the one you need.

thanks alot