Guide: Why Etch A PCB When You Can Mill?

January 4, 2018 by Adil Malik 83 Comments

I recall the point I started taking electronics seriously, although excited, a sense of dread followed upon the thought of facing the two main obstacles faced by hobbyists and even professionals: Fabricating you own PCB’s and fiddling with the ever decreasing surface mount footprints. Any resistance to the latter proves futile, expensive, and frankly a bit silly in retrospect. Cheap SMD tools have made it extremely easy to store, place, and solder all things SMD.

Once you’ve restricted all your hobbyist designs/experiments to SMD, how do you go about producing the PCBs needed for prototyping? Personally, I dread the thought of etching my own boards. The process is laborious and involves messy chemicals and specially sensitized PCB’s — none of which interest me. I’ve only ever done it a few times, and have promised myself never to do it again. Professional but cheap PCB manufacturing is more like it board pooling services such as OSH park have made this both easy and affordable — if you can wait for the turnaround.

So what are the alternatives? If you are really serious about swift prototyping from your own Lab, I put forth the case of milling your own PCB’s. Read on as I take you through the typical workflow from design to prototype and convince you to put up with the relatively high start up cost of purchasing a PCB mill.

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CNC Milling Is More Manual Than You Think

November 27, 2017 by Elliot Williams 43 Comments

I was in Pasadena CA for the Hackaday Superconference, and got to spend some quality time at the Supplyframe Design Lab. Resident Engineer Dan Hienzsch said I could have a few hours, and asked me what I wanted to make. The constraints were that it had to be small enough to fit into checked luggage, but had to be cool enough to warrant taking up Dan’s time, with bonus points for me learning some new skills. I have a decent wood shop at home, and while my 3D printer farm isn’t as pro as the Design Lab’s, I know the ropes. This left one obvious choice: something Jolly Wrencher on the industrial Tormach three-axis CNC metal mill.

A CNC mill is an awesome tool, but it’s not an omniscient metal-eating robot that you can just hand a design file to. If you thought that having a CNC mill would turn you into a no-experience-needed metal-cutting monster, you’d be sorely mistaken.

Of course the machine is able to cut arbitrary shapes with a precision that would be extremely demanding if done by hand, but the craft of the operator is no less a factor than with a manual mill in making sure that things don’t go sideways. Dan’s good judgment, experience, and input was needed every step of the way. Honestly, I was surprised by how similar the whole procedure was to manual milling. So if you want to know what it’s like to sit on the shoulder of a serious CNC mill operator, read on!

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Home Built PCB Mill Reportedly Doesn’t Suck

July 2, 2017 by Lewin Day 16 Comments

It’s 2017, and getting a PCB professionally made is cheaper and easier than ever. However, unless you’re lucky enough to be in Shenzhen, you might find it difficult to get them quickly, due to the vagaries of international shipping. Whether you want to iterate quickly on designs, or just have the convenience of speed, it can be useful to be able to make your own PCBs at home. [Timo Birnschein] had just such a desire and set about building a PCB mill that doesn’t suck.

It might sound obvious, but it bears thinking about — if you know you’re incapable of building a good PCB mill in a reasonable period of time, you might save yourself a lot of pain and lost weekends by just ordering PCBs elsewhere. [Timo] was fairly confident however that the build would be able to churn out some usable boards, however, and got to work.

The build is meant to be accessible to the average hacker who wants one. The laser cut & 3D printed parts are readily available these days thanks to online services that can manufacture for those who don’t have the machines at home. [Timo] uses a rotary multitool for a spindle, a common choice for a budget CNC build.

With the hardware complete, [Timo] has spent time working on optimising the software side of things. Through careful optimisation of the G-Code, [Timo] has been able to improve performance and reduce stress on the tooling. It’s not enough to just build a good mill — you’ve got to have your G-Code squared away as well.

Overall, the results speak for themselves. The boards don’t suck; the mill can do traces down to 8 mil, and even drill the holes. We’d love to have one on the workbench when busting out some quick prototypes. For another take on the home-built PCB mill, why not check out this snap-together version?

Restoring A Strange Milling Machine From Craigslist

June 1, 2017 by Adam Fabio 25 Comments

[diyVT] found a real white elephant in this milling machine from Craigslist. It cost him only $200, cheap for a small mill, so it was worth the gamble. We’re not sure what to call this — it’s not exactly a gantry mill, not a horizontal mill, and definitely not a knee mill. The tag says V-Mill, made by either Pierce West or Tree Tool and Die Works, depending on which ID plate you read. The Tree has a three-phase motor, but it came with a phase converter, so it should be good to run on single phase 220 volt household power.

The machine was in good physical shape, at least until the previous owner attempted to move it out of the garage. During the move one of the cast iron chain drive handwheel brackets broke into three pieces. Cast iron is no fun to weld. It has to be pre-heated, welded with nickel rod, and slowly cooled. Some hackers would have given up or built a new part, but [diyVT] accepted the challenge. He put the puzzle pieces back together, grooved them out with an angle grinder, and welded everything. The result wasn’t pretty, but it only has to take the force of the handwheel and the 200 lb gorilla spinning it.

After a bit of work on the motor and head, including a new belt, this tree was ready to cut. [diyVT] snuck out of a family bar-b-que to cut his first chips on the new (to him) machine.

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Making An Inexpensive DRO

May 26, 2017 by John Baichtal 22 Comments

[Andrew] wanted a digital readout (DRO) for his mini lathe and mini mill, but found that buying even one DRO cost as much as either of his machines. The solution? You guessed it, he built his own for cheap, using inexpensive digital calipers purchased off eBay.

The DRO he created features a touch screen with a menu system running on an LPCXpresso, while smaller OLED screens serve as labels for the 7-segment displays to the right. The DRO switches back and forth between the lathe and mill, and while the software isn’t done, [Andrew] hopes to be able to transfer measurements from one machine to the other.

In a very sweet touch, [Andrew] hacked cheap digital calipers to provide measurements for each axis, where they provide a resolution of 0.01mm. There are six daughter boards, one for each caliper, and each has a PIC that converts from serial to I2C, freeing the main firmware from dealing with six separate data streams.

The DRO doesn’t have a case, [Andrew] has it positioned out of chip-range from either machine.

A previous DRO we featured in 2012 used an Android tablet as its display.

Hackaday Prize Entry: A CNC Mill Without The C

March 30, 2017 by Jenny List 17 Comments

It’s a staple of home CNC construction, the 3D mill built on the bench from available parts. Be the on a tubular, plywood, or extruded aluminum frame, we’ve seen an astonishing array of mills of varying levels of capability.

The norm for such a mill is to have a computer controlling it. Give it a CAD file, perform the software magic, press button, receive finished object (Or so the theory goes). It’s a surprise then to see a mill in which the input doesn’t come from a CAD file, instead all control is done by hand through the medium of a joystick. [Mark Miller]’s 3D printed freeform carving machine is a joystick-controlled mill with a rotary tool on an arm facing a rotatable bed, and it can perform impressive feats of carving in expanded foam.

You might ask why on earth you should make a machine such as this one when you could simply pick up a rotary tool in your hand and start carving. And you’d be right, from that perspective there’s an air of glorious uselessness to the machine. But to take that view misses the point entirely, it’s a clever build and rather a neat idea. We notice he’s not put up the files yet for other people to have a go, if someone else fancies making CNC software work with it then we’re sure that would be possible.

There is a video showing the basic movements the mill is capable of, which we’ve put below the break. Best to say, though, it’s one on which to enable YouTube’s double speed option.

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The Elements Converge For ±.002 In Tolerance

February 20, 2017 by Michael Uttmark 51 Comments

What can be accomplished with just a torch and compressed air? We can think of many things, but bringing a 17-foot-long marine shaft into ±.002 in tolerance was not on our list.

Heat straightening (PDF) utilizes an oxy-acetylene flame that is used to quickly heat a small section of a workpiece. As the metal cools, it contracts more than it expanded when heated, resulting in a changed volume. With skill, any distortions on a shaft can theoretically be straightened out with enough time (and oxy-acetylene). Heat straightening is commonly applied to steel but works on nickel, copper, brass and aluminum additionally.

[Keith Fenner’s] standard process for trueing stock is sensitive enough that even sunlight can introduce irregularities, but at the same time is robust enough to carry out in your driveway. However, even though the only specialty tools you need are a torch, compressed air and work supports, watching [Keith] work makes it clear that heat straightening is as much an art as it is a science. Check out his artistry in the video below the break. Continue reading “The Elements Converge For ±.002 In Tolerance” →