Build Your Own PCB Milling Machine 210
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."
Amateur (Score:1)
Whatever happened to the guys that were going to print out boards on inkjet printers?
Also since these would be milled, they would be called MCB's. Get it straight.
Milling machines, while a marvel of modern technology in their own right, cannot create multi-layered circuit boards, unless you ignore the obvious extra steps involved. Sounds like overkill, and a solution looking for a problem.
Re:Amateur (Score:4, Informative)
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.
Re:Amateur (Score:3, Insightful)
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.
Las
Re:Amateur (Score:1, Insightful)
Yeah and traditional boards are ECBs right?
"Milling machines, while a marvel of modern technology in their own right, cannot create multi-layered circuit boards, unless you ignore the obvious extra steps involved."
Yeah and etching a board obviously couldn't either, could it??
Troll alert!
take a breath... (Score:2)
Re:Amateur (Score:5, Interesting)
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 [t-tech.com] 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.
Comment removed (Score:5, Informative)
Re:Mirror (Score:2)
milling machines are cool (Score:3, Interesting)
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.
Re:milling machines are cool (Score:1, Funny)
Re:milling machines are cool (Score:2, Informative)
It's a plotter (Score:2)
I'm surprised that as the old school plotters get decomissioned, more people haven't snatched 'em up.
Re:It's a plotter (Score:2)
I've got the feeling all the old flatbed plotters were dumpstered many years ago.
Re:It's a plotter (Score:2, Interesting)
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 looki
Re:It's a plotter (Score:2)
I was referring to the old table-top flatbed A and B size pen-plotters - the ones that either held only one pen, or some of the fancy ones that had a carousel of 4 or 6.
Last one I saw was at a ham-fest several years ago... think they had it for $20 and no-one bought it.
At the time, the idea of making a PCB mill out of it never even crossed my mind.
Scanner guts...r (Score:3, Interesting)
Re:Scanner guts...r (Score:2)
One of the coolest things was a controller called the Beasty that would control up to 8 R/C servos, allowing fine control of various devices. I even wrote a Z80 assembler program on a Sinclair Spectrum to drive the Beasty via
Re:milling machines are cool (Score:4, Interesting)
You underestimate what it take to make a good mill. A none computer controlled Bridgeport Vertical Mill will set you back 16 grand depending on how you option it. There are not a highvolume thing. It takes massive peices of perfectly machined metal to do this. Theres a lot to it. You can't just cheapen one up without it becomeing well cheap.
Adding Computer Numeric Control is not so easy. Though i'm sure if someone wanted to do it it would not be impossible. But there is a heck of a lot to G code (what runs CNC's). You'll be working the bugs out for a while. And then you still need a CAD program to pop out G code, thats a few grand there at the cheapest level. Granted if you want to spend a lot of time you can code it by hand. Many machinist do much of the G code by hand, but they do that everyday.
There are reasons CNC's aren't cheap, Mainly the fact everything about them is expensive. If you ever get to see a real high end CNC mill or lathe going you will understand why the cost $100K to a million bucks. Watching one at work will blow your mind. Especialy if you stick your head in it.
Re:milling machines are cool (Score:5, Interesting)
As for CNC not being easy, it's not easy, but it's not impossible. Especially if all you're doing is PCBs. How expensive is the software? Dirt cheap. You can use the free version of TurboCAD to make your parts. You export them as DXF files. Then the program that controlls your motors can convert that to gcode for you (or you can use another piece of software). You can get free DXF->GCODE converters that work quite well. You can also get free software to run your motors, or nice commercial programs for $20.
It's true that a "real" CNC machines start in the 10s of Ks, but you can make one that will do just about everything a hobbiest will ever need for just a little. For more information see my other posts to this discussion, or see John's [crankorgan.com] website.
Re:milling machines are cool (Score:2)
Re:milling machines are cool (Score:3, Interesting)
For those wondering, a milling machine is like a drill press, only the part can be positioned accurately relative to the spinning metal cutter, and the cutter and head is designed to take side loads as well as axle load encountered in drilling. In all machine shops, calibration marks are in increments of 0.001", or 0.01mm. A human hair is usually 0.003", and most skilled operators can
Re:milling machines are cool (Score:2, Informative)
Re:milling machines are cool (Score:3, Insightful)
I do know G code, I had to learn it. It's not the hardest thing in the world, but it's not the funnest thing either. it's like playing 3D logo. But making software to take a 3D ca
Re:milling machines are cool (Score:3, Interesting)
I make about 20 PCBs a year (with FeCl3 etching). It would be nice to just go into the store CD and blank copper clad board in hand and rent the machine for an hour for $50-$100 and make 5 boards.
Since the boards are generally all different or at most 2 copies of a single one, I can't justify spending $80 for each board at a place like PCB express. This is just a hobby after all :
CNC Engraving Machines (Score:2)
As for drilling the PCB holes, I found that a good set of second-hand carbide bits, a dremel drill press, and a thin center punch could provide nearly perfect results. You *MUST* center-punch with
Re:milling machines are cool (Score:3, Informative)
Try your local high school or middle school industrial technology teacher. I betcha you could work a deal where you could use their equipment if you can provide something of value to them in return, other than money (although a few bucks for the budget never hurts). Most valuable is your time and expertise. Least valuable, most likely to get you a no answer is anything that is going
Re:milling machines are cool (Score:2)
I didn't know high schools still had any tech equipment at all.
Jason
ProfQuotes [profquotes.com]
Re:milling machines are cool (Score:2)
I agree with you. I thought it was a stupid idea when they got rid of the tech courses and I still do. I value what I learned in auto mechanics a lot more than my practice using a flatbed scanner.
Jason
ProfQuotes [profquotes.com]
Re:milling machines are cool (Score:2)
> actually prestigous.
There are places where it isn't?
Re:milling machines are cool (Score:5, Informative)
I don't think you could reach
Re:milling machines are cool (Score:2)
are careful about temperature of the surface being
worked and if you machine slowly with sharp bits
you can get 0.0001" precision, i.e. 2.5 micron.
Going beyond that requires a polishing jig.
It is not uncommon for people to give specs to the
machinist with the precision of a few micron but
that HAS to be dimensions at some given temperature.
At those precisions, thermal expansion matters.
Re:milling machines are cool (Score:2, Informative)
dremel cnc [crankorgan.com]
big links [corbels.com]
mini zoltar cnc(using dremel) [rcmodels.net]
slashdotted already (Score:2, Funny)
2 comments so far and its already down. What's the point? The article might as well be yanked all together.
Re:slashdotted already (Score:2)
There are easier ways (Score:5, Informative)
Re:There are easier ways (Score:2)
Re:There are easier ways (Score:2)
Yep: These guys [quickparts.com] will do small SLS parts for $N, where N is in the mid-hundred range.
SLS is great for checking fit and function of your design; less useful for actual structural use. They (or other places) can however take an SLS part and form an RTV mold around it, from which they can cast urethane parts. For quantities less than 1000 pieces it's a lot more cost-effective than having an injection-molding tool made up.
Re:There are easier ways (Score:2)
Re:There are easier ways (Score:4, Informative)
ExpressPCB [expresspcb.com]- Has an offer that will let you make 3 3.8"X2.5" 2-sided boards for about $60, as well as a more general off that's not too much more pricey. They have their own board design software you have to use, which is a bit primitive but adequate for hobbyist use, though it's a problem if you were to ever want someone else to make your boards.
Advanced Circuits [4pcb.com]- Has a deal to make 2-sided boards for $33/ea, min qty 3. These boards have a solder mask, which is required for dealing with fine-pitch SMT parts, and makes your board all pretty and professional-looking ;-)
Sierra Proto Express [sierraprotoexpress.com]- Has a similar deal to Advanced Circuits, but also has a good price to make four-layer boards.
Some general notes- I've used the first two, and it worked alright, but I haven't tried the third one. The latter two require Gerber and Excellon data- this is the standard format for PCB plotting and drilling information information. Essentially any board layout software should be able to generate them. However, it is not trivial to figure out what precisely to send the board manufacturer- you can't just blindly trust your layout software to do the Right Thing. I keep meaning to write a little tutorial on my hard-won knowledge about this, but I've never gotten around to it :-/
Re:There are easier ways (Score:2, Informative)
I use PADS PCB ver 7.0 for DOS to generate the Gerber photoplot, aperture, and excellon drill files. Once I have the fileset intact, I zip them and email my rep ( in my case, Anthony Estes ) over at Advanced Circuits with my zipfile package as an attachment, and about a week later I get a large padded envelope in my mailbox with my boards in it. Every one has been exactly what was ordered. Excellent workmanship. And on time.
Getting started is the har
Re:There are easier ways (Score:2)
Now, Olimex [run.to] will do up a single small double sided, masked and silk screened board for 26 bucks. They'll panelize it for free too, so you can use a decent free tool like Eagle, which is limited in the PCB size, and still get the whole board.
Just be sure to have them ship it via regular mail, otherwise UPS will charge you about 75 bucks brokerage fees for bringing it into the country.
Re:There are easier ways (Score:5, Insightful)
Granted it's only double sided - but at that it's wonderful. Wow, no more chemicals! I've always-forever wanted one of these but the pro milling machines are out of my league.
Re:There are easier ways (Score:2)
Re:There are easier ways (Score:2)
Re:There are easier ways (Score:2)
Do It Right - John Has Great Plans (Score:5, Informative)
If you want to build a machine to mill circuit boards, do it right. Build a machine designed by John C Kleinbauer [crankorgan.com]. The Brute [crankorgan.com] 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 [ezboard.com].
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 [woodenclocks.co.uk] and more.
Re:Do It Right - John Has Great Plans (Score:3, Informative)
can be 5 mil wide or even smaller. I am saying this
because I had a design which needed to have ultra
thin traces and have them straight (low capacitance
and inductance were key). This method just isn't
accurate enough for the most demanding PCBs.
Re:Do It Right - John Has Great Plans (Score:2)
Re:Do It Right - John Has Great Plans (Score:2)
Steve
It's a shameless plug, but.... (Score:3, Informative)
I'm sure this will kill his pipe, but here is a link: www.cnczeus.com [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.
TurboCNC (Score:2)
It really works on machines down to 486-SX33, it has a HUGE and growing user base and support network, it is actively being developed (version 4 almost out!). Best of all, it is free. As in, you can download a the full working program and use it as much as you like. If you want the source code, it's $20. That's a much better deal than any other functional CNC program out there, and you think you'll ever see the source?
EMC is out there, but...forget it. It's
Re:It's a shameless plug, but.... (Score:2, Interesting)
I could not agree more with what you said.
I would bet you in five years time, that DOS system will *still* be chugging along just fine.
I work with systems like this all the time in the robotics world. You do not have to be a gigahertz machine to spin steppers! There is *nothing* to be gained once you can process faster than the physics of mass and energy will allow.
Now, *most* (not all) of my clients are in business to make money. They want to set up a machine to crank out something, and do
Acid etching is nearly extinct (Score:4, Interesting)
Re:Acid etching is nearly extinct (Score:2)
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.
I don't know any hobbyists who do this either but a former employer still etches photoresist boards in ferric chloride. The techs call it ferrocious chloride and despise building boards. The ferric chloride is a hazmat and everything exposed to it's fumes, rusts. If you spill any on your clothes, toss 'em
Re:Acid etching is nearly extinct (Score:2)
Re:Acid etching is nearly extinct (Score:2)
If you are referring to the picture at the bottom of the page, be aware that it is probably far from being the finished product. Also large areas of copper are often left on circuit boards to serve as part of the ground plane.
Does anyone out there know if there are any truly printed printed circuit boards, i.e., unclad boards upon which the traces are laid down with some sort of
Electronics Enthusiasts... (Score:5, Insightful)
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?
Re:Electronics Enthusiasts... (Score:5, Informative)
http://www.goldmine-elec.com/
http://www.alltr
http://www.allcorp.com/
http://www.ne
http://www.jameco.com/
Try to never buy from Radioscrap. Overpriced and crap quality...
I've ordered from Alltronics before. They have a $15 minimum order, and sometimes an order may be delayed if something you requested is out of stock. They answer your e-mails rather quickly, though.
Jameco also sells the seemingly elusive PCI prototyping cards [jameco.com], though they're pricey ($70). Anyone know another supplier of these? (They're also good if you're looking to pick up a 266MHz PII motherboard for $20)
=Smidge=
Re:Electronics Enthusiasts... (Score:2)
I've seen them at Fry's...they're even more expensive there, but if you need one right away, that's another option. (Assuming you have a Fry's nearby, of course...)
Re:Electronics Enthusiasts... (Score:3, Interesting)
I'm certainly curious, and the multiple articles about home-made tools for dabbling with electronics certainly contribute to my curiosity. The problem, however, is two-fold. One, some of this is rather daunting for most beginners. I see some of the talk about people on here building their own circuitboards and such, and I'm a little intimidated, frankly. Two, I wouldn't know why to dabble in ele
Re:Electronics Enthusiasts... (Score:5, Informative)
As much as I'm annoyed with Radio Shack for turning into a toy and appliance store (they used to be an electronics hobbyist store), they do still have a handfull of items for the electronics tinkerer.
I'd recommend picking up all of their Engineer's Mini-Notebooks to start with.
I'd also recommend checking out some of their X-in-one kits... I think they have a 300-in-one now (I hope they haven't stopped making these).
They have all kinds of example circuits that you can make by hand wiring (read: no soldering) the circuits together - and some of the examples are kind of cool for a beginner. I started with a 150-in-one kit (it was the biggest at the time) way back when I was a teen.
After this... if you want to get into digital electronics, pick up the TTL Cookbook and CMOS Cookbook by Sam's.
If you want to get into audio electronics, pick up the Audio IC OP-Amp Applications (also by Sam's).
If you're a musician, there's a VERY cool one called Electronic Projects for Musicians by Craig Anderton. Use this one with the above audio book to come up with some really cool guitar effect "pedals".
I hope this helps!
Re:Electronics Enthusiasts... (Score:2)
I second this recommendation. The second project I ever built, and the first board I ever etched was his four channel mixer. The author does a very good job at making the projects inviting to beginners.
Also, if anybody in the Sin Lab down at WPI happens to be reading this, I want my copy back!
Re:Electronics Enthusiasts... (Score:2)
Moreover, interfacing computers has become much more compl
Re:Get off my lawn you little punks!! (Score:2)
Sounds like you missed this article [slashdot.org] from Friday...
Coming Soon! (Score:2)
Useless (Score:3, Informative)
Re:Useless (Score:3, Insightful)
Re:Useless (Score:2)
If you thought that was bad. (Score:2)
Thankfully, the pin pitch is often a little bit easier to deal with, so it's not QUITE as difficult for making boards.... As long as you're willing to make multilayer boards.
The problem is SOLDERING the damn things! The balls are UNDER the package, facing the board, wit
Re:Useless (Score:3, Interesting)
Not true. I have also used such machines. They are actually very useful. Yeah you can't make a new motherboard for your PC with them, but for making quick prototypes they are great. You get your board the same day, and if you made any mistakes, you can fix them the same day and make another board, you don't have to spend time waiting for someone else to do things, the mail, etc.
As far as SMT goes, they can handle
Re:Useless (Score:2)
You should also consider that this technology does not apply solder masks, and does not do plating of pads/vias, or tinning of exposed surfaces. Bare copper is not very suitable for soldering, and it oxidizes quickly.
When I say "unconditionally useless" I mean it. Myself,
That's all well and good.... (Score:2)
Re:That's all well and good.... (Score:2)
You buy the board that way from any real electronics parts supplier (read: probably not Radio Shack).
The boards are fiberglass (or fibreglass if you're in the UK), with copper cladding on one or both sides.
Re:That's all well and good.... (Score:2)
Re:That's all well and good.... (Score:2)
Can you still get the photo-resist chemical? I used to buy the MG Chemicals positive photo-resist, but they don't seem to make it anymore. They just sell the pre-treated boards.
I'
And for the real, hardened professional. (Score:4, Interesting)
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.
Recursive construction (Score:3, Interesting)
CNC Milling Machines (Score:2)
I used a small CNC miller to produce two complex alumnium plates that I used to produce a winch. It was complete overkill, but I was bored, and it did a very good job.
It had dodgy software and the sheet I was using was too large (X and Y) to use in the machine, so I had to make a jig using MDF and steel rod to locate the plate, so that it could be flipped, and the machine used to cut material much bigger than it was designed for.
The software and PC controlling it was updated last year, and now it can accu
Isn't it a salt? (Score:4, Informative)
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!
Re:Isn't it a salt? (Score:5, Informative)
Yes, it is a salt. Copper is more reactive than iron, so the etch works by the chlorine trading iron for copper. The "filings" left after etching are the iron that was freed in the reaction.
Some folks see it anything that 'eats' away at something as being caused by an acid, even if no acid is really involved. Wouldn't it be nice if chemistry was taught? And taught in a way that was effective?
Not Just Ferric Chloride (Score:2)
Milling machine (Score:2)
Now they just need to ma
Re:Milling machine (Score:2)
Re:Milling machine (Score:2)
UV Light does the trick (Score:3, Interesting)
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.
Polychlorinated Biphenyls (Score:2, Funny)
Don't bother (Score:2)
Realistically, PC boards are made by sending output from a board design program to a service that makes boards. It's reasonably cheap, turnaround is good, and you can get double-sided with plated through holes, which is what you want.
Toner transfer methods are for people who like looking at their boards under a magnifier and doing rework. Do it yourself photographic methods work better, but few people bo
Clever of you (Score:2)
pretty unfortunate (Score:4, Informative)
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.
Re:pretty unfortunate (Score:2)
To plot.. (Score:2, Insightful)
Milling machine (Score:3, Informative)
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 [mit.edu]
A mill is... (Score:2)
In reality it's much more complicated than this, but you get the idea.
The bits are not pointed, they have flat ended cutting flutes. There are exceptions, of course, like ball-end-mills (but that's just adding to the confusion).
A mill in a machine shop can be used to make quite complex parts out of a billet (big chunk) of metal. It's table can move in X and Y axis, and the mill-bit moves in the Z axis. They can get much more complicated than this, b
Re:A mill is... (Score:2)
Re:A mill is... (Score:2)
That really sucks, they used to be great!
I guess too many companies are going Mazak.
Dunno, been out of that business for over a decade.
Re:A mill is... (Score:2)
http://www.hardinge.com/Pages/16_bridgeport.htm
-=- Terence
Re:okay, where can I buy a pcb milling machine? (Score:2)
Replace the pen with a high-speed cutter and then you can interface to the plotter quite simply through the RS232 port or whatever the plotter supports.
Here's a plotter on eBay [ebay.com] that might be a good starting point.
Re:PC Motherboards (Score:2)
Just think of the microwave frequency considerations & the complexity of routing traces in a multilayer board. Yow.
Re:PC Motherboards (Score:2)
Re:I could see where this could be handy (Score:2, Insightful)
How could "ugly" construction perform better on something so sensitive to impedance and trace layout and length as RF?
--
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. wi