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Build Your Own PCB Milling Machine
mwandel writes "It used to be that one off amateur printed circuit boards were all etched in acid. A lot of companies nowadays use a special form of milling machine to mill them out of solid copper clad circuit boards. This guy Jonathan Westhues built his own PCB milling machine out of various parts, with a laminate trimmer as the milling head. Lots of other neat hacks on his Webpage as well."
Comment removed based on user account deletion
More people need to be able to make their own parts out of steel and plastic. The problem is cost. It's curious that a country that is inventive as ours doesn't have some type of affordable CNC(computer numeric computation) milling machine.
Affordable metal cutting lathes are expensive too.
/. really needs a mirroring system or at least ask guys like this and/or give them fair warning to prepare.
2 comments so far and its already down. What's the point? The article might as well be yanked all together.
..mork
Seems like a lot of trouble to go to when it's pretty cheap to get small-quantity custom boards done.
They're still called PCBs even if they are milled. It's a naming convention that has stuck. It is in no way incorrect.
Also, It is not difficult to make a double sided PCB with a milling machine. There are many times in circuit board design that you don't need more than one or two layers. This is a solution that solves a lot of smaller problems every day.
If you want to build a machine to mill circuit boards, do it right. Build a machine designed by John C Kleinbauer. The Brute is designed to make PCBs cheaply. I recently bought some of John's plans (well worth it) and they are quite nice. They are very well done, easy to understand, don't need things that are exotic and hard to get (if your in the US). He includes a booklet on how to mill PCBs with The Brute, or you can order it seperatly. He even maintains and activly participates on his forum, Hardware Store CNC.
I've started to build a brute, and things are going pretty well considering I'm doing this in my spare time with only some time to work on it. If you guys are like me (I really like to build things with my hands) this is a ton of fun. I can't wait to get it running so that I can make PCBs, robot parts, a wooden clock and more.
Comment forecast: Bits of genius surrounded by a sea of mediocrity.
My dad wrote some CNC control software that would work quite well for this application. It's designed to run anything from table top machines (such as this) all the way up to large scale CNC retrofits, where the iron is good but the control is shot. Very competitively priced as well. Even has a free demo version with no time limit for those that want to check it out. Requires a dos based machine to run it on though. FreeDOS works fine, of course so does MS-DOS.
:)
I'm sure this will kill his pipe, but here is a link: www.cnczeus.com
It's listed in google as well, so you may want to check that out if/when the pipe goes dead from the load.
Good article for those that don't already have access to PCB milling equipment. There really is no reason to do the old-school etching method anymore, in fact, I don't even know any hobbyists that do that anymore. Milling equipment can be found, borrowed, or made pretty easily these days. I've even seen a working setup made from Lego Mindstorms and a cordless Dremel! Hey, it works and beats the heck outta the mask-and-acid roll of the dice method.
It seems dabbling in electronics is a dying hobby for the younger crowds... I hope projects like this spawn new curiosity and interest.
i tcellar.com/
For those new to this hobby... here are some publications that could be of great value to you:
http://www.nutsvolts.com/
http://www.circu
http://www.poptronics.com/
Anyone know of any others?
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Milling is the process of cutting by movign a quickly rotating cuting head in relation to the item being cut down. Most machine shop milling machines have a stationary head, and move the item around, while some cnc machines have a head that moves.
Of course, questions like this are where search engines come in handy -- http://www-me.mit.edu/Lectures/MachineTools/mill/i ntro.html
Build it, and they will come^Hplain.
I can't get to the site (slashdotted). But I used one of such machines. Nowadays they are absolutely, unconditionally useless. They can't make the fine traces that are required for modern chips. Instead, it is cheaper now to order your PCBs from a board house (such as Advanced Circuits). $30 per board is not that expensive.
The best thing about this milling machine is that it built itself. The first version was controled by electronics on a breadboard. The second version uses much more sophisticated electronics on a PCB that had been milled by the first version of the machine. That is unbelievably elegant.
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Isn't Ferric Chloride (the stuff you buy in bottles at Radio Shack, or at least I did when I was a kid) actually a salt? FeCl... looks like a salt to me!
Over here, (in school at least) we just print out the circuit diagram onto a transparency sheet (inkjet printer of course) and then just use a UV light to destroy the appropriate parts of the circuit.
Use some chemicals (stored in a safe location and brewable in your own home) and you've got a nice PCB for you to use.
Milling machines are not an overkill or a solution for amateurs, they are a very good solution for inexpensive prototypes or production needed in small-mid volume.
:)
Acid etching produces a functional board, but it simply does not look good, and you can't make 100 boards that are exactly alike. The lines are almost straight, the edges are not perfect, and if you are on a contract to deliver a product, this is not an option. Examples of where a milling machine is one of the best solutions: a university lab where the researchers are under government/industry contract and are supposed to deliver a working prototype or a small business with a military contract (small volume products).
I worked for a startup company for a while, and part of my job was to work on a QuickCircuit milling machine, and that thing had milling bits that were 4 mils thick (comparable to hair). You can hardly reach this precision with acid etching. I also adapted the machine to dice wafers, which replaced the company's practice of using an exactoknife
If you are in the IC design business, testing cheaply is of primary importance. You can get a full setup for producing boards for less than $10K. How's that compared to billions of $$$ for setting up an IC production plant? And if you are in the RF design business, you need the precision so that a crappy board does not screw up your high-frequency measurements.
Of course, milling is no option for producing high-volume PCBs with many layers, but don't think that ASUS spent months to design such a board to test their new motherboard design. First they have to verify that design works, which is done with a cheap PCB design, one that would hook up the ICs. Only after that stage can the final PCB design begin.
As long as the Z80 or 68K processors are still in use, simple PCBs will be here, and we need a cheap and fast way to design and make them.
Scanners are essentially a flatbed plotter with only one axis of travel - cheap USB scanners can be had for under $30.00, buy a couple to get a two axis system, third axis could be a simple solinoid config. There would still be a lot of work left to do to get it all to go together, but it could be done (whether you stuck with the USB stuff, or just kept the stepper motor and drivers, then added you own custom interface). Also, back in the early 1980's there was a BYTE magazine article on building your own plotter (not that difficult)...
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On the contrary, large flatbed plotters are pretty popular for sign cutting, routing, etc. I used to work at a large custom print company, and we had a couple WILD plotters hooked up to a Xenix server.
At the time I left, they had 2 Zund tables, complete with conveyors, automatic sheet feeders, roll feeders, with a nifty camera hooked up to the cutting head that would track 1/4" dots on the media and compensate for stretching/shrinking that is common with the 3M vinyl that we used.
A while back I was looking through the Zund catalog, and they have all sorts of heads for their plotters, such as routers with z axis, laser, etc.
When we bought the Zunds, we sold the WILD tables to someone else (though I'm not sure why anyone would bother, they were known for their controller board problems.) I doubt that any functioning table would be trashed so readily.
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The most serious problem comes in from the really high-end etching systems. Photoresist is fine with ferric chloride, but when you start using something like an acid-peroxide etchant, it will actually eat many "resist" inks. The resist pens become TOTALLY useless, for example.
And so this is where the old technique of serigraphy comes in. This is the "screen-printing" that makes the name Printed Circuit Boards. The resist ink used on the actual board is usually just some form of lacquer, which holds up well to even the harshest etchants. A stencil is prepared on a screen, usually through a photographic process. Since the screen resist doesn't have to deal with the same harsh chemicals, it is generally much more environmentally conscious and cheaper than PC-Board photoresist.
I actually set up to do this method myself, in a semi-hobby context. I had some previous experience with serigraphy, and the acid/peroxide system was cheaper, far more effective, and much easier to dispose of than the ferric chloride. On the flip-side, it will eat virtually anything metallic and smells aweful (it isn't much of a health hazard except in the sulphuric/peroxide system, but should be ventilated nonetheless), so it's not for the faint of heart.
Hardware, software, and blinking lights!
I dont know about milling, but I've got a PCB mining machine right here: a fishing pole dipped in the East River.
This is one of the cooler "News for Nerds" articles I've seen in a while and its completely unreachable at 4 in the morning because of the slashdotting.
this is no longer humorous. As much as I often enjoy the +4 comments on certain articles reading slashdot is pretty much no longer worth the frustration of not being able to RTFA.
Can't wait till this article moves down the frontpage.
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This is quite cool.. I wonder if you could hook up a drill to a normal flatbed plotter.. You can find old Roland plotters quite cheap on ebay and places now..
"Never let the truth get in the way of a good story..."
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How could "ugly" construction perform better on something so sensitive to impedance and trace layout and length as RF?
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Simple--you have a continuous ground plane underneath your components, which means that ground leads can be made as short as possible. Also, since you're not constrained by layout, you can ensure that inter-component leads are as short as possible, and that the input is nowhere near the output, etc. etc.
It's often the case that there are fewer problems, less stray capacitance, etc. with ugly construction over PCB construction.
As a benefit, it's faster as well.
Once in a great while, we got a board with a funny pattern for some traces, and he pointed out those were actual circuitry. He said that at high enough frequencies, an engineer could play with the trace pattern and fiddle with impedence or frequency attenuation.
Lastly he said of course we can call them whatever we want - but whatever the customer says, goes. The customer was always right. :-)
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