Anybody using pcb2gcode?

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Sorry, I don't want to be in that business. Shipping is a killer! :) Please check with your local fab shop or get an estimate from a reliable supplier outside your area.

At the risk of starting a religious war, I'll mention that I've been delighted with AP Circuits:

--Winston

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Ohhhhh No you don't! :)

I ran screaming from iron-on boards and press'n'peel and photopositive and Budda knows what other gimcrackery that was available over the years.

My milled PCBs were the first that actually came out properly and worked. No weird chemicals, no pinholes, no smears, no cracked traces.

--Winston

It depends on how fast we need them. We have paid S&H of $30 from China (FedEx) and $1 from Colorodo (USPS 1st).

We use several fabs, Lead time between 2 to 4 weeks. We do 2 to 3 batches of PCB per month.

Mostly the time required to operate it, and the mess, and the non-plated bare-copper boards.

APC can do a few boards, here in 3 days, for under $100.

As long as your time, and the equipment, are cheap.

John

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The economy must be on the mend! :) That was the kind of lead time I had back during the 'boom'.

Seriously, though. There is no way I could compete on price, quality or turnaround time.

Thanks anyway.

--Winston

Yeah, there are some good deals coming this way.

A gal was asking me last week how to get some papers to her parents in Beijing and Fedex wanted about $90 for an envelope. 8-( Went with registered mail for around $20.

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Lots of times it comes down to 'shipping cost'. My favorite vendor needs $26.00 to send me two 1" x 2" pcbs.

That is like what, >$4160. a pound? Yikes!

--Winston

I don't know why some companies insists on FedEx or UPS. USPS can ship for $1 or $2 in a day or two later. However, Digikey keeps shipping me leadless chips in trays or tubes. They need a big box to pack them and charge me postage after they ship. I wish they can just dump them in an envelop (with anti-static bag inside, of course).

I suspect it is a profit center- they get a huge discount off the list price and charge you the list price. Otherwise they'd have to raise their prices, and you might not think it's such a great deal. Maybe they think it weeds out cheapskates who are likely to complain about other things.

Well, *you* asked how to speed it up, and we gave you the answers. You didn't like them, now we know the real story. You *like* futzing around with expensive, noisy machines! :)

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I thought I clarified by saying: "Let me rephrase my question.

If you've milled PCBs, what package did you use to generate the necessary G-code from your Gerbers and Excellon files? How did the process go, overall? "

See, I already know how to speed up that particular process. (Automating the process of converting PCB CAD files to be compatible with CAM.)

That wasn't the question.

I'm familiar and comfortable with the other PCB manufacturing processes. That wasn't the question either.

Let me see if I can help.

First part: "If you've milled PCBs..."

OK. That narrows the range of answers to include information regarding the process of mechanically milling PCBs as opposed to say photolithography or other ways of doing this.

Next:

"..what package did you use..." In other words, please name the software you employed to partially or completely convert your Gerber and Exellon files to G-code for CAM processing.

Next:

"How did the process go, overall?"

Here, I ask the relative level of satisfaction the user had with the task of creating a mechanically milled PCB from their normal design file output. Additionally, I imply that I would like to hear about shortcomings of a particular approach or tool. Alternatively, I would like to hear if an approach or tool worked particularly well.

and we gave you the answers.

You've got me there. There *were* random noises emitted after I stated my question. That does meet the legal definition of the term 'answers'.

I was rather hoping for information about the process of mechanically milling PCBs, though.

Well, yeah, I do. They are paid for, and fun to run.

Will you now interpret my latest answer as a request to know more about photolithography? Really? Again?

:)

--Winston

There is nothing to say about the machine that is not already known: Simply export gerbers for top, bottom, contour, lettering (if desired) layers. Export also drill files.

These are imported into the CircuitCam program which computes the path for the mill(s). You can have rubout zones where all unused copper is removed, interesting for RF stuff.

The generated files are imported to the BoardMaster program which directly controls the drill/mill. You place the project on an A4 board with sufficient remaining area and the current project is drilled, milled and cut from the board.

Next you scrub the board with scotch-brite and you can start soldering! You certainly have to minimize the number of vias! In the past we used simple wire soldered at both sides. Now we usually use small rivets which we are also soldered. There is a system to metalize the holes based on dispensing a kind of paste that is afterwards cured but even the LPKF folks seem to discourage this!

With this approach we have build several two-layer boards with 0.5mm pitch FPGAs and associated chips. For prototypes it is fast and good enough. Chinese PCB manufacturers are however an increasingly attractive alternative!

Pere

That's all we need to know. You don't actually want to make PCBs better or faster. You want to jusitfy your poor choices to yourself, and maybe your wife.

:)

--Winston

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I wonder if the vias can be plated using an 'electroforming' process?

Very interesting! Thank you.

--Winston

With solder mask, white print and plated holes?

Within a week? What is taking so long?

Quick turn around PCB manufacturers can get you a PCB within 3 days (including shipping). I agree making a PCB yourself is always faster (a matter of hours) but the end result cannot be compared with a PCB made by a PCB manufacturer.

(I like yellow silkscreen better because it contrasts more.)

You are right. A milled board does not have any of those things unless one applies them later. The purpose of the board is simply to verify proper operation of the electronics; not even as a 'first article' product.

The manual process of creating a toolpath for the cutter in G-code. That's why I'm asking for the opinion of other folks that have also made PCBs using the milling process. Not photolithography.

Milling. The application of a mechanical cutter to remove undesirable copper from a laminated substrate. Not the use of resist and acid to etch away the copper. I've had boards made using that process and am comfortable with it and understand its strengths.

I would like information about people's experiences with the mechanical rather than the electrochemical process though.

I'm really trying to be clear here. :)

You misspelled 'two weeks' in the context of a reasonably priced PCB.

Sure it can.

• Fewer unnecessary features

• Much higher cost for tools to create the board unless you already own the hardware.

• Very much cheaper and faster if the toolpath delay can be solved

• Admittedly a much greater time commitment.

There are many other points of comparison as well.

Can we please stop beating the 'photo lithography horse'? I've used that process before and will use it in the future. It is outside the context of my question, though.

--Winston

You already came up with the pcb2gcode software. It looks like it solves your problem. Why don't you just try it?

Most 'millers' I know use the LPKF machine for a while but then switch back to using PCB manufacturers. This is mostly in commercial environments though. The software for the LPKF machine seems to have quite a learning curve.

The machines from Sherline look nice but I wonder about the tolerances. The DIN connectors on their stepping motor kits are flaky though and no position feedback.

The real solution to a problem is almost always outside the context of a question :-)

Yes, but the setup for making plated-through holes is complex enough that it's not worth it for single board runs.

With plated-through holes, the traces are held to the board at every hole, and are much less likely to come off the board. So you can use finer lines.

If you really want to make your own boards, photo-etching is the way to go. (The toner-transfer thing sort of works, but there are usually flaws in the board.) But really, the quick-turn board houses are fast, cheap, easy to use, and Internet-connected to CAD systems.

As someone who actually does CNC milling, it's just not the right tool for board-making.

John Nagle