His separate guide on CNC is great. He also has a great intro to electronics. His first book is an amazing survey of totally passive attacks. His second book is a comprehensive survey of web application osecurity.
Edit: Almost funny to see FTP actually being used to, you know, transfer files. As Scotty would say, "How quaint!"
Something that struck me about this article -- and something which I see regularly around CNC hobbyists -- is the unfamiliarity with basic machining calculations, a problem that usually results in chipped parts and broken tools. I didn't even know about machining fundamentals like chipload/chip per tooth (CPT), inches per minute (IPM), and correct RPMs for different materials until fairly recently. Additionally, "climb" versus "conventional" milling refers to how the bearings are loaded -- you almost always want "conventional" unless you're on a nice CNC machine. Why isn't there more information crossover into the hobbyist world?
Anyways, kudos to the OP for throwing this out there, and thank you Zalewski; I'll be methodically absorbing pretty much everything linked to in this essay. :-)
OTOH, had he started by trying to understand the process of machining without focusing on whether the tool is being controlled by a human or a computer, he'd find that there are thousands of hobbyist machinists online running fully manual machines that will happily share the knowledge you mentioned. Machine tools have been around for 200+ years. The basic techniques haven't changed very much in all that time.
TL;DR: do the research first.
Of course, I'd also say that for many people, a typical type of reaction to CNC machiningi is: "Oh, you just put the file of your 3d part in the machine and it makes it!" Nope, not that easy.
...do you have a recommendation or two for books/resources for learning about machining?
Youtube is one of the better resources right now, for anything other than really basic calculations. There seems to be a trend of old-school professional machinists documenting jobs they're working on - sort of a cross between a tutorial and virtual job-shadowing. Some nice users include oxtoolco, KEF791, Abom79, and mrpete222.
That said, an introductory book that the local community college just recently started using (before that, there really was no book, just blueprints and notes because so much information came from the instructors) is the Precision Machining Technology .
Unfortunately, like many textbooks, it's not cheap. But it's a nice introductory book("I don't have a clue, but I'm interested in the topic")
I understand it's possible to fall back on solipsism whenever life gets challenging or you have to admit something unpleasant, but many of us relish it and don't need to fall back on that sort of philosophical crutch.
I am not suggesting that one needs a philosophical crutch like my pithy platitude above to justify laziness.
I am merely suggesting that constant internal battle with yourself is not very productive.
Shigley : http://www.amazon.com/Shigleys-Mechanical-Engineering-Design...
Used copies are probably cheaper, and the information hasn't changed in any meangingful way in ages.
Publishers got used to the idea they can charge as much as they want on US for textbooks. Higher education already costing so much, who would neglect books? This is not the case in developing countries (specially India).
Well I still think that buying an american mechanical book seems like a bad idea outside the US. My world is ISO, and american standards are a pain for us: fractions, inverted units like mesh sizes or thread pitch, letter drill bits (that one I never understood since they also have fractional sizes) and variable standard between screw diameter and pitch (actually ISO has coarse and fine pitch, but it's always coarse unless fine is explicitly designated). People who think we could just divide everything by 25.4 would be really naive. Even metal designations are different.
And probably more useful to you.
It reminds me of my youth, the professors loved garage doors, cinema film advancing fingers, and shitty kinematic simulation software.
Also on the site; Dial-a-threat: http://lcamtuf.coredump.cx/word/ Shannon's Ultimate Machine: http://lcamtuf.coredump.cx/ultimate/
I better get going. I am not getting any younger
ME's scoff at the very existence of Sketchup, but for a free modeling tool, its good enough.
If you like something more programming oriented, OpenSCAD is great for parameterization. You literally code your 3D model.
Neither of these tools comes close to something like SolidWorks, but they both get the job done.
A 3D printer is probably the easiest and cheapest method of fabricating your designs, but the ability to make functional parts is fairly limited
Sherline sells a small tabletop mill for something close to $1000.
Grizzly sells a bigger one for $1300.
Both of these can be retrofitted for CNC for around $2000.
There are now 3 offerings of complete tabletop CNC mills for $2000 to $2500 (Nomad, Othermill, and Carvey)
If you can program, learning GCode will be a breeze.
CAM is probably where most of the learning curve lies. This is where machining knowledge is most beneficial.
If you are lucky enough to live in certain metro areas, Techshop has several locations across the US. Its essentially a fitness club but with machine shop tools instead of exercise equipment. You pay a monthly fee, and you can use everything. They have several different types of CNC machines, as well as training.
I like your description of TechShop, and imho it's about 50% true. They do allow use of the tools after you've paid an extra $100-$200 for a "Safety and Basic Use" class on each, which is usually a 3 hour session providing just about enough information to not kill oneself on a machine. Not to knock it -- it's a great way to get access to tools in many situations -- but in all honesty, after a semester of machine shop at the local junior college, I'm no longer stumped about why I kept breaking drill bits in blocks of aluminum.
If you know Spanish check the tutorials on OpenScad and Freecad of Obijuan:
Cubify Design, although not open source, is one of the cheaper 3d cad tools which also supports parametric modeling.
It was very, very promising, right until the moment I started doing a real design in it. I hit so many bugs and problems, that I couldn't finish the work. Debugging constraints was pretty much impossible: if something went wrong (and it almost always did), I'd have to restart from scratch.
I can compare it to SolidWorks, which I also used, where debugging constraints is also a major pain point (why don't they make this easier?), but at least it's possible. And it is buggy, too, but much less so than Cubify, which means you can actually get things done.
From my point of view (external perspective of a software engineer), 3D modelling tools suck, in general. Few support parametric modelling, which consider a must-have, and those that do are pretty poor at it (discuss after you've created a parameter-driven assembly of multiple components in SolidWorks, and then decided to change a parameter name/value or move a parameter from a component to assembly-level).
I would welcome your thoughts on just how to best hack these exact types of parametric changes in SolidWorks, especially at the component to assembly-level transition. It does seem pretty hopeless, as you say.
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BTW, top-down building (e.g. starting from the assembly) has never worked for me. I always end up with an unmaintainable mess — but that could be my poor skills.
It doesn't support assemblies yet (although its on a branch!) so I just designed a linkage system extremely carefully and swiss cheesed some parts to avoid dealing with dimensions as much as i could. I used to use Inventor but Fusion 360 is nice - and its free for startups.
As soon as Freecad supports assemblies I will probably switch back. I hate booting into OSX for Cad work and back home to linux for coding.
Looking to move XY stage with fine resolution: 5 micrometers
The stage will only need to support ~5grams
 There will be optical feedback
 speed can always be sacrificed for accuracy
- Instead of the classic steppermotor setup, I was wondering about the feasibility of servos with arbitrarily reduced gearing (let's say a stack of laser cut planetary gears).
-What are the pitfalls of this method? has anyone else done something similar?
I don't know where he finds time to sleep.
But really, awesome page.
A nice taste of the gentle humour waiting for you in the article!