As somebody trying to get into mechanical engineering while living in a small urban apartment, this has been an incredible resource... not that I've made much progress along the lines it describes though.
It's tough to plan a path toward growth in these skills without sustaining inordinate expenses at each step. I can't afford to become afflicted with Gear Acquisition Syndrome. I've come close to dropping huge sums of cash on tools before discovering, at the last minute, critical reasons that they could not do what I need for the designs I have in mind. Maybe I'll visit a makerspace? Ah, but every one in my area appears to have gone defunct since Covid year zero.
So the journey up to this point has been:
- A lot of reading: not just faffing around with hobbyist blogspam -- full-on MechE textbooks, learning what really goes into engineering schematic diagrams, all that good stuff
- Getting back up to speed with the pencil-on-paper geometry and math skills I've lost after years of doing all my intellectual work in digital form (at least I can still draw a freehand circle)
- Proto-proto-prototyping: just making some physical objects roughly of the same geometry as what I've designed -- whittling them out of wood, sculpting them out of polymer clay
- Hacking together janky tools: trying to make a crappy mini lathe out of Meccano-clone parts, trying to make a crappy mini lathe out of an electric drill, just to get a basic feel for what's involved
- Apologizing to my wife for all this weird scary stuff in the corner of the apartment
I was a CS major. The only hands-on physical engineering I did in college was cooking a single-transistor chip in a freshman applied physics lab. Basically I feel like someone who has studied everything about the physics of bicycles but has never ridden one. I'm really struggling on how to proceed.
I was a mechanical engineer before I shifted to software development (so kind of the opposite of you) and I think you need actual, full on college level schooling to be a mechanical engineer in most cases.
The stuff you're focusing on - basically manufacturing techniques - is a very small part of engineering in general. I didn't see any mention of CAD or FEA work, but even assuming you do know some of that or can access that type of learning you still are missing a lot of what makes an engineer an engineer.
The biggest difference I see between software developers and mechanical engineers is a way of thinking. I realize that sounds very woo, but it's very obvious to me and to other mechanical engineers I've spoken to.
For example, around my area there are schools that give out "Mechanical Engineering Technologist" degrees, which are quicker, less math intensive engineering degrees. Often times speaking to METs, I notice how they don't see connections between certain phenomenon or see why certain physical phenomenon happen in one circumstance but not another.
This isn't to discourage you. I think one very easy step you could do if you haven't already is pick up Fusion360 (it's free for hobbyists I believe) and try to simulate making a simple project. I would hesitate in calling this "mechanical engineering" but I think it would get you along in your goals.
Sorry for the long rambling message, the interplay between software and traditional engineering is something I think about quite a bit...
> The biggest difference I see between software developers and mechanical engineers is a way of thinking. I realize that sounds very woo, but it's very obvious to me and to other mechanical engineers I've spoken to.
As a fellow trained ME, yes, it seems obvious to me as well. A good school and program will have you spending several years in intensive study and thought about the fundamentals and wider implications of the physical principles and mathematics of machines and systems. If you can then follow that up with a few years of good hands-on professional experience with the subject of your study, it's going to give you a level of insight into the workings of the physical world that is difficult to achieve just through direct experience.
Which is not to say that you can't succeed in manufacturing without an engineering degree. It's pretty common for experienced machinists/welders/etc. to break out of a career cul-de-sac and go into business for themselves and engage in some effective and knowledgeable engineering in the process.
But there's no shortcut. You either do the schooling, or you earn the experience. Otherwise, you're not even going to be realizing the mistakes you're making.
I think mechanical engineers require or develop a more pragmatic attitude. Do-overs in the mechanical realm are often more time consuming or expensive than those in software. And practical experience comes with a lot of learning.
Beyond the expense and time, mistakes can also be very dangerous. I take a lot of pride in designing industrial machines that are not only effective at their task, but safe to build and operate. The products that I've had a hand in are touched by a lot of people, and it's my responsibility to make sure that the energies being transformed by the machine are not unleashed in ways that are harmful to people. Laziness or lack of care on my part will get people hurt.
Fully agree. Even if I am not a full mechanical engineer I am an industrial one by training. And over half of my studies was equivalent to what the mechanical engineers did as well. And somehow that affects how think about the world and stuff, engineering thinking of sorts.
I am im supply chain management now, and compared to others in thay domain that are really good SCMs but not engineers, thinking like an engineer makes things easier sometimes.
I also agree on using the old hands on the shop floor when it comes to manufacturing and machining parts, engineering / design for manufacturing is something a lot of engineers struggle with. Also goes for maintenance and what not. And the good engineers listen carefully to that kind of feed-backband actually search it. This was one something my profs pointed out to us all the time as being an important part of our future jobs. Obviously, some people are better at that then others.
I'd actually suggest a slightly different tact. The initial commenter seemed to want to learn how to make things. To me, that sounds like they want to be a skilled machinist (in the general sense) instead of a ME.
Some of the most brilliant people I've ever met are gruff old dudes in a machine shop. They don't use CAD because they can hold an entire design in their head. You ask them about a change to a part, and they tell you why three other parts need to be modified if you want to make that change.
These "old school" types (in my experience) actually have a deeper understanding for the interplay of physical phenomena in a design. They might not know the specifics of the underlying reasoning for said phenomena, but they can absolutely tell you what the outcome will be and how to avoid it.
How'd they get started? Apprenticeships, usually. But how did they get good? They made stuff. A lot of stuff. Eventually you'll get good at it.
Just keep doing what you're doing. And wear your PPE. And try not to chop any fingers off.
I read this as the OP was wanting to dip their toe into "making", not to do some self-directed learning such that they'd call themselves a MechE. Schooling would be great of course, but if your goals are very modest, I think what the OP has in mind might be fine too.
It'd be like telling someone fooling with Python that they need to take a full CS degree otherwise they'll fail to appreciate the beautiful mathematical underpinnings of functional programming. That might be true, but that's also not the goal.
Yes, I was implying "to do stuff like the author of the article does" ( https://lcamtuf.coredump.cx/rstory/ ), coming from a very similar situation as him -- as a software engineer with an already broad general scientific and technical background, in a small apartment, getting into the concrete particulars of designing and building cool mechanical projects on a small scale and budget.
I mean, the last few lines I wrote still stand if that's what you want to do. I would learn some CAD software, download a few files and try to cnc or 3D print something. Even in that link, I saw a screenshot of some CAD software.
I personally use a Sainsmart 3020. It's relatively cheap and pretty small. For my goals, it gets what I want done. I used to have an Ender 3 Pro for 3D printing but had to give that up. If you want to get into the business of manually using a lathe or something, more power to you, but why when we live in an era of desktop manufacture? But regardless of what equipment you use, you need something that can inspect, possibly edit, and transfer the design file to the equipment i.e. CAD.
Can I ask you a couple of questions? I am in a patricular situation, I'm a mathematician who does FEM and I think my training has been too abstract. My most recent work involves programming custom code in C++ for the study of buckling of thin shells (finite element method, continuum mechanics, differential geometry of shells, and all under the umbrella of functional analysis). Still the region I live in has virtually no relevant positions for FEA, which prompts me to ask:
(1) I've been thinking of getting a certification in ANSYS or Abaqus (it's relatively cheap). Would it help if I get some certs, or would it be enough to have expertise in several open source finite element programs? - think deal.ii, PETSc, MFEM, MOOSE, FreeFEM, FEniCS and the like. I really like to use the latter because apart from being free, they give me more freedom and I can use them with parallel computing on UNIX machines.
(2) Regarding manufacturing and machines/machining, any book or resources that stood out? I'm most familiar with the Machinery's Handbook.
(3) For design, did you use a tablet? I've been looking into buying one and use it for design, preferably with FOSS. Any recs?
>Regarding manufacturing and machines/machining, any book or resources that stood out? I'm most familiar with the Machinery's Handbook.
I went to a top tier school for MechE and Materials, and would recommend two intro books: Engineering Mechanics Statics by Meriam and Kriage and Shigley's Mechanical engineering Design in that order . If you fully understand the contents of these book, it probably puts you in the top 10% of mechanical engineering graduates.
For a broader education, you can read Fundamentals of Heat and Mass transfer by Incropera, DeWitt, Bergmann & Lavine as well as Fundamentals of Fluid Mechanics by Munson, Young & Okiishi.
Understanding these two books will probably as well will probably put you in the top 1% of grads.
If you have a strong background in mathematics, these mostly deal with applications of linear algebra and differentials, so the value is understanding the applications.
From there, you can branch out. If applicable, Ogata's Modern Control Engineering and Tongu's Principles of vibration
Most undergraduates dont really understand these due to the heavy application of Laplace and Fourier transforms, but are relevant if you want to build complex machines.
Excellent overview. I'd also add "Marks' Standard Handbook for Mechanical Engineers" to the front of the list. Its a great way to dip your toe into the breadth of the field and will serve as a nice reference book on your shelf later if you keep going with it.
I started down the path to be a materials scientist and wound up in embedded hardware, so take my opinions with a big grain of salt.
For self-learning, I don't know if anyone would work through the problems in a statics textbook. Shigley looks good. Thanks for that recommendation.
For heat transfer, I eventually wound up on the bibliography from Hot Air Rises and Heat Sinks by Tony Kordyban, which is more focused on cooling electronics. I have Holman's Heat Transfer on my shelf as a result and I can recommend it for self-learning. One big advantage to Holman: he shows how to set up common thermal problems in Excel in an appendix. I would consider recommending a good continuum mechanics book in the place of a fluid mechanics book - I liked Yuan-Cheng Fung's First Course in Continuum Mechanics but I haven't looked at it or anything else in its domain for a while.
Ogata is a good controls text. I don't know if any of them are good for self-learning. I tried and had to take a class to wrap my head around feedback control. Tongue looks interesting. Thanks for the recommendation.
It is a really simple book and not particularly academic, but you have to start somewhere.
It is basically the equivalent of a picture book, with 200 pages of free body diagrams, which may be helpful to someone if they aren't used to thinking in terms of beams, forces, and moments.
The entire books' contents is probably covered in pages of Shigley's, and perhaps for some people that is enough..
Ah yes, it was hard for me to tell the difference even reading the spellings side by side.
That said, it is definitely the weakest of the suggestions. The rest are serious books that a professional might refer back to. On the other hand you should really never need to refer back to a statics text, and it could be switched out for any number of options.
I really appreciate the recommendations. I have enough knowledge of the field to understand that control engineering and vibrational modes are extremely important but not enough to know what's most important to know about them or which books are more reliable or better written.
What do you think about Reuleaux's Kinematics of Machinery and the Machinery's Handbook?
I don't have experience with your kinematics book, and have some limited exposure to machinery's handbook. My impression of the latter is that it is good and highly regarded, but perhaps more on the Practical fabrication side then engineering Theory.
If you can get access to student or lite versions of some FEA software, start using them. I've found few places have cared about my software certifications, and more than I can adjust to their software package of choice. Some places will have higher requirements, but not all.
Machinery handbook rocks, but it is far from perfect. It's great for machining, it doesn't cover all of mechanical engineering. I've leaned hard on Roarks formula handbook through my career. A materials reference book goes a long way too. More recently referring frequently to degarmos manufacturing book.
I've used a cheap-ish Windows laptop for almost all of my research and design. CAD can suffer as assemblies get large, I turn fancy rendering off as it is mechanical engineering, not making prettying renders. FEA can eat resources fast. I've pushed to a beefier desktop as required. I've done some CAD on a tablet, but I hate the form factor for it.
There's an MIT course on OpenCourseware that's called (roughly) "How to make (almost) anything" and also "FUNdamentals of Machine Design." (or something like that!) I think they're by Richard (?) Slocum. I started a long time ago and cherry picked the parts I cared about. Slocum's writing is very entertaining and he's easy to follow along with.
> The biggest difference I see between software developers and mechanical engineers is a way of thinking. I realize that sounds very woo, but it's very obvious to me and to other mechanical engineers I've spoken to.
I'd say it depends whether the software engineer learned core computer science. That's maths heavy and teaches you equational reasoning, which similar to the skills used in solving systems of equations that govern physical systems.
> The biggest difference I see between software developers and mechanical engineers is a way of thinking.
Can you give an example? Myself being a mechanical engineer who also turned to software development, the people I talk to from SW are used to dealing with large matrices and semi-complex math. Sure they don't know about modal analysis or Navier–Stokes equations, but the lack of a certain way of thinking I cannot recognize.
As the other comment and a few others have iterated, software guys don't have as much of a "measure twice, cut once" mentality. It's not so much about the math or technical knowledge, it's more of a mentality.
Let me put it this way - I've seen many times software engineers laugh when they encounter a funny bug or an output they didn't expect. I don't think I've ever seen an ME laugh when something breaks.
Take a woodworking class at your community college.
Focus on the serious fundamentals first. I mean like how to hammer a nail into a thing, how to screw things together. Learn the difference between nut+bolt, Truss Head screws, and pan-head screws. Learn when to use each of these things.
Visit Home Depot. Build a damn coffee table.
Focus on the fundamentals. CNC Mill comes after all this IMO on the hierarchy of knowledge. You really should be extremely familiar with fasteners (Glue vs Nuts+Bolts vs Screws vs Nails) before you start designing things that get glued/screwed/snapped together.
--------------
Most things are left unsaid because just building a damn coffee table (or similarly simple / small object) is everything you need to know about beginner level mechanical engineering.
Finding a class (community college) with this basic level of skills really is the bulk of it. Once you've accomplished the basics, it becomes obvious how to use a CNC Mill or 3d printer or whatever these electronic tools are.
Woodworking was also my gateway into CNC and machining metal. The most important lesson it taught me was that every manufacturing process has a system of tools around it. One tool is almost never enough to build anything of quality. Early on, I was very interested in the charm and ingenuity of individual tools. After learning more and working in the field, I realized that building sophisticated things is all about the integration of tool systems into stable, predictable processes. A holistic approach is necessary.
There's a 18 part video series by Dan Gelbart I can recommend where he goes over how to prototype products using a laser cutter and a hydraulic press. If I was setting up a home shop, I'd start there. I have very good access to CNC milling and turning machines, but usually find it cost and time prohibitive to go that route, preferring to laser cut/3D print wherever possible.
https://www.google.com/url?sa=t&source=web&rct=j&url=https:/...
Urban apartment, I'd stick to electronics, pcb, soldering, code.
You want meche career change, just go work in a local cnc machine shop that runs Fusion 360. Then you can have unlimited access to all the tools you could ever want. If you want to be a good designer, I'll sell you my book once it's written.
> Maybe I'll visit a makerspace? Ah, but every one in my area appears to have gone defunct since Covid year zero.
Yes. I miss TechShop, where I did CNC machining. It's not all that difficult. Maybe 100-200 hours to minimal competence.
What's left of the maker movement seems to have been taken over by little old ladies into crafting. Gluing construction paper and macrame, not machining and welding. Activities classes for middle schoolers where they assemble kits, not original work. In the early days of TechShop, it was people making rocket engine nozzles for the X-Prize, and people who commuted to Shenzhen to get their stuff made in volume. Four Bridgeport mills, all going at once.
The problem is that none of them are what I would call "cheap" anymore.
> Activities classes for middle schoolers where they assemble kits, not original work.
Don't look down on this. Assembling an electronics kit is what got a LOT of us greybeards into electronics. Debugging something you put together is non-trivial.
We now have a couple in my city of 300k people, I go for blacksmithing and welding (have to soon to finish something for family that lies there since November...). Or if I need some heavy woodworking machinery, luckily I have quite a bit of smaller machines at home, most of which inheritence of my late grandfather. Time permitting, I like manual work like that, good counterbalance to an otherwise typical office job.
> As somebody trying to get into mechanical engineering
As a career? I'll assume "yes".
Go to college for ME. Not one of the big brand-name schools. The local one that services the regional mechanical engineering industry. Tell them you want a career change. If you're serious about it, they'll bend over backwards to make it as feasible as they can. They'll also be brutally honest about whether you've collectively reached the point of feasibility yet.
I'm saying this as someone who is very outspokenly critical of universities as unnecessary gatekeepers.
A question to answer: is the enjoyment coming from actually being the machinist, or is it coming from assembling something you designed? The answer could be either. But if you just want to bring something you designed to physical fruition and you are limited on space then I would recommend finding machine shops that will make what you design for you. This is what Protolabs, Shapeways, Xometry, etc do. You don't need to actually have a 3D printer or laser cutter or CNC mill to get things built. You can probably find a local fabricator too. I found a guy that made handrails and would do random welding jobs, I used to go to his shop for all sorts of different things. Even if you get the money and space to build out a shop, there's a lot of skill to these crafts and people dedicate their whole career to becoming experts in them.
The goal is the end product, yes. But there's joy to be had in getting there. And more importantly, I know I won't be able to achieve it without a good feedback loop for iterating on my designs, which means doing at least some machining on my own.
For one thing, sketching out variations on a design typically reveals there's a wide space of possible parameters in the spec. In many cases it's obvious that only a small subset will actually be technically feasible (either for machining or for reasonable functionality of the finished artifact or both), but not obvious exactly what that subset will be.
I'm not even talking about what could be revealed by finite element analysis or other formal methods (though I'm not averse to learning those too). I mean the feel, the taste, and the intuition I can't get from just drawing and doing the math. Like Jackie Stewart said, "You don't have to be an engineer to be be a racing driver, but you do have to have Mechanical Sympathy." I have mechanical sympathy for computing systems, for rapidly narrowing down appropriate design spaces in software projects, but I don't yet have mechanical sympathy for mechanical systems.
Similar position here. CS major who went to work software / FAANG pretty much for my 30 year career.
Something about mechanical engineering feels amazing, unlike software getting real tangible /physical/ results from your work. I feel the CS experience gives a very distinct advantage as well here. Software and CAD isn't scary for a CS brain. CnC (additive and subtractive) seems like logical way to do everything, which is what makes cool parts for projects.
I've acquired a few cheap Harbor Freight welders and oxy/acetylene cutting tools, started with small CnC routers to carve soft metals for parts. 3d print what I can't do in metal.
One really easy area to get into for a software dev is robots, look into RoS, an open source robotics OS based on Linux, order some parts from the RoS wiki. And you can get to your own advanced little r2d2 pretty quickly (real-time 3d mapping of your house, arm with gripper control, voice control, image recognition in real time) - most of the software pieces that ME might struggle with are not so difficult for CS folks, and it enables some really cool results!
Hey man, actual Mech-E here. Also general mechanical hobbyist and handyman; not just one of those CAD guys
Just some quick things that may help you point you in the right direction. This is coming the "small scale hobbyist", not indusdrual profesional viewpoint:
-getting better and making actual projects come to fruition is actually a lot like CS. A lot. Somebody can spend all their time reading CS theory, textbooks, MITOWC, whatever. Their technical foundation will be strong, but will struggle when it comes to coding syntax and spesific program/firmware issues. Some get stuck in that mode and are paralyzed to take action
I'd honestly recommend dropping the mech-E textbooks to read just for reading's sake. It will fill you with generic knowledge but not a better builder. Instead I'd be thinking about "what do I want to build"? Kitchen knives? Custom pens? Automotive mods? It does not need to be something you make forever. Just something that seems fun now (just like the pet CS video game project)
Just like CS hacking (in the PG sense), THEN you will start to look up how it's done. Kitchen knives need metal forging? Okay, now its time to look up edu material for that. What tools are needed? Can I custom-make tools to get them cheaper? What edu material is out there for that… rinse and repeat
...just remember 2 things. 1, safety first. 2, a pretty drawing means nothing if you can't manufacture it to your desired specs
-honestly, drafting or 3D modelling, it's all fine. What's important is what allows you to implement your ideas and record them fastest. Also, right tools for the right job
I made a bench for my balcony. Just rough, imprecise measurements, knowing I'd make ad-hoc cuts to size when I had my material
For extreme lightweighted, funtion-over-form stuff or geometrically sensitive stuff, ya, CAD or FEA software will be needed
Just use whatever is appropriate and will allow you to achieve the results you want. Honestly, if you're not making F1 parts, drafting or CAD is fine
-your proto-prototyping is GREAT. This is exactly how you get started into this. Try something out on a small scale, see where you could improve with tooling, materials, methods and process, try again. Want to make a bronze casting? Try plaster casting first. You say you're lost, but you are ahead of 99% of people in all the damn makerspaces or home hobbyists. Trust me :)
-janky tools. Beautiful. For things that don't need to hit specifications (like firm +/- tolerances), this is one of my favourite things to do. I made an air extraction unit with a thrift shop electric leaf blower motor and some scrap hvac conduit. This is a crucially important skill IMO, as mechanical things get expensive. This allows you to go MUCH further with the money invested to try things out
-collecting weird stuff? Get some plastic bins. Lol. Out of sight out of mind
And last tip? When things around you break, try to fix them. That really starts to add to your "mechanical intuition". I'm pretty familiar with hvac, plumbing, general indusdrial fastners, air and fluid power systems. Next time your sink clogs up, don't call the plumber right off the bat. Explore tutorial videos to see if you would be comfortable doing it (and no problem of you're not; i am not with electronics). But at least you start to get very familiar with standard tools, parts, designs, etc. It's almost uncanny how similar many product classes are
Mech eng here as well. This advice is great. I work in a high tech firm, prototyping through in-house production. Stuff breaks and we fix it. We make prototypes with the wrong parts, the wrong tools. We do our design, send out parts for machining, and often end up fixing stuff by hand because of a design oversight (it happens, it's prototyping, not production).
I find when people outside the "handy" diciplines (factory operations, industrial setting eng, skilled trades), they think mfg and engineered components are much more elegant than they really are
Perhaps things like apple, F1, dyson and defence distort that view. They do make their products with "spaceship" technologies. But it's critical to understand they are the exception, not the norm... plus... the treasuries and workforce they can utilize to pull it off
It's hilarious how products like Yeti, cammelback, premium razors are just permutation of very simple products (not knocking them one bit and great marketing). x2 the quality of standard products for x4 the price (and often that's just fine)
Usually products start out a little jank just like software. Red bull and lululemon come to mind. Start small leveraging available things, start local markets, scale from there. Just like FB with Harvard students
High voltage and radiation equipment here. Our products are sleek, or prototypes you literally would not touch with a 10ft pole. Jank is part of the game. If we can run a bunch of sketchy tests for $100s to find a path forward, and do pre production on the order of $1k to $10k, we might justify that $100k purchase down the track. On the other hand, we might find our own method that means the $100k solution is never required. We fail fast when we can and learn what we can.
There are stacks of subsystems that can be tested quickly, janky, yet safely. Safety is always paramount, but a relative term. Safe for an end user, and safe for a prototype engineering test need not be comparable. Similar safety, for sure, similar longevity, ease of use etc., potentially very different.
For tests on prototype subsystems like a cooling system? Totally fair game
Live full production systems? Usually no one will be willing to risk the OSHA or ISO violations where critical failure affects safety. Or, if they do, that company won't last long
Also, to add on to the reading comment - keep an eye out for old (40's->70's in particular) technical books and manuals on topics that interest you. I find they had a way of conveying information that was somewhat lost once video became commonplace.
fixing stuff will teach you everything! i didnt even mean to learn so much about so many topics, but knowing that i could fix it just kinda made it happen. and its mostly fun, when its not incredibly rage inducing lol
I have to get this out of my system. No, your YLOD on your PS3 is most likely not caused by the tokins capacitors, it is the solder bumps on your RSX GPU silicon die. You can't fix those cost effectively, just get a replacement RSX.
Also, reballing the BGA solder balls doesn't fix the solder bumps inside the RSX.
Absolutely. It's like viewing the source code of a launched CS product and become familiar all the python libraries they used
You start to hit the next threshold when you start to become a mad-max salvager. Fan motor controller is broken but the motor is fine? Salvage the motor, chuck the rest!
Whats your goal/motivation? How to proceed would depend a lot on that. Tinkering as a hobby? Making something physical? Understand how things are made? Prototyping an idea for commercialisation? Career change?
I think CNC machining is primed for developments that make it much easier to use for the home hobbyist. The tech is very close to what's needed for 3D printing but it has a few added requirements like the need for a sturdier frame and accommodations for a fairly large and powerful motor. Both are solvable with the right materials and the motor can be anything from a DC spindle to a repurposed wood router. The biggest hurdle to overcome would be the software. Right now, Fusion360 is the defacto standard for hobbyists but it leaves a lot to be desired for ease of use and handling complex models that a lot of people would like to mill. Having software that is as easy to use as a slicer for 3D prints would be a huge win.
The ability to make metal parts and carvings is a game changer even if you are somewhat more limited in the features that you can carve with a CNC vs 3D printing.
The other small fab tool that I think would be great to streamline would be a small foundry for casting aluminum, brass, and bronze but that one is much more difficult to automate beyond having a furnace with good presets. An ideal machine would be something similar to an injection molding machine for plastic but capable of melting metal, perhaps using induction heating with a graphite crucible and spigot for depositing the metal into a mold.
I'm also somewhat convinced that there may be a way to do aluminum extrusion with a much smaller setup than is normally used but the pressures and temperatures involved may make that uneconomical for an individual.
I love your optimism, and would absolutely love to have this capability in a garage. But as someone who designs physical products (and deals with all of the manufacturing techniques you mentioned above on a regular basis) I can't say I agree. There's a huge amount of knowledge and skill required to make machined/cast/extruded metal components, and a very steep learning curve before someone can do so safely.
Gamechanger? Yes. But likely mostly for the ambulance industry.
> Gamechanger? Yes. But likely mostly for the ambulance industry.
While I laughed, I don't find this to be very true at all for working in metal.
Working on metal seems to have WAY fewer injuries than people who work on wood. Metal working is almost always in a vise and your hands are on levers/cranks--away from the cutting surface.
Whereas, with woodworking, your hands are almost always the motive force and directly next to the cutting envelope.
Simply take a look at the hands of long time machinists vs long time woodworkers. The woodworkers are the ones missing some finger bits.
It really depends on what area of industry you are in and the safety culture of the shops you are around. I hear a lot of stories of really bad safety practices in metalworking. Including the exact inverse of your statement about machinists/woodworkers and missing fingers. I would also argue that accidents with common machine shop tools like lathes and mills may have higher consequences than your average table saw or jointer in a cabinet shop. The "potential energy" is higher so to speak, although I'm not trying to downplay the forces involved in something like a table saw kicking a workpiece back. For example, there's a prominent post on r/machinists now where a poster witnessed their coworker getting sucked into a lathe (fatally). This is not something that is a risk at most cabinet shops, but is a risk at most machine shops. That accident was indirectly caused by disabled safety interlocks on the lathe, an unfortunately common practice in the industry. All anecdotal evidence, of course, but I think machine shops have a different risk profile that isn't necessarily less risky overall.
I don't know, I'd have thought the angle grinder - signature tool of the metalworker - is probably one of the most dangerous tools you'll find in the average DIYer's garage.
Agreed. I've seen a lot of people coming from 3D printing become interested in CNC and assume the complexity, risk and investment are similar. They hit a wall pretty quickly when they realize all these things are much higher when machining metal. There are a lot of hobby mill companies willing to perpetuate this assumption by selling cheap benchtop mills. But to do produce anything with "industrial" precision, strength and surface finish at a decent rate, the physical size of the equipment alone is more than what most garage shops are willing to accommodate.
I've often considered a CNC Mill though. A huge variety of plastics are readily available from McMaster-Carr of varying machining qualities (Acrylics are best for Laser cutters, but you can get extruded Nylon, Cast Nylon, extruded ABS, etc. etc.). There's also a wide variety of cheap woods available.
This guide focuses on Urethane Casting, which is yet another set of plastics you can work with.
-----------
I've worked with all of these plastic technologies and materials, not necessarily in my lab but in various Makerspaces. Its all easy enough, and "safe enough" to work with.
Obviously, even woodworking equipment can chop off your limbs. So you should go in with a degree of woodworking training and/or study. But there's plenty of woodworking classes available at community colleges everywhere. Take one of those and you _should_ be set for wood/plastic level cutting tools (like a CNC Mill).
------
Taking the next step into metalworking... ugggh. I know people who take that step, but it is another level of safety / study above and beyond wood/plastics. I'm happy with my woodworking level of knowledge (and its incredibly practical, especially if you're a homeowner).
The problem is that once you start adding up the cost of the components to make a capable CNC mill, you get really close to the price of existing ones. Ball screws, good linear rails, etc. are no joke. Big heavy castings (cast iron or polymer concrete) are no joke. The most "disruptive" maker-style machine is the Tormach and it's not well liked.
Lots of open source designs that can route steel, like PrintNC [1] and OpenBuilds [2]. If all you need is Aluminium, then you can make do with something like the RS-CNC32 [3] or MultiBot [4].
Not parent, but I’d consider 0.001” over 10” to be totally acceptable for home and hobby use and 0.00025” over 20” to be acceptable for general production use (“great” isn’t really meaningful, but “makes parts to spec” is good enough).
That's the specification of a measuring instrument. Commercial VMCs don't hold 0.00025” over 20" even without being loaded. A slight temperature change will throw that off.
What you say is correct, except that a hobbyist can source parts from Ebay and the like. Which you could never do for a production machine. That can bring the cost WAY down.
I cast aluminum in my backyard frequently. My forge is made from 2 one gallon paint cans, some charcoal, and a hairdryer. It cost me less than ten dollars to build. It's only as complicated as you decide to make it.
I've seen successful CNC machines which used a Bosch router as the spindle. The bearings were good enough, the motor could maintain speed as the load varies, and there was a strong round metal case you can mount to the XYZ drive. Brass and soft aluminum could be machined.
Steel, no. Milling metal, you're supposed to cut, not grind. Underpowered metal cutting means you can't take a big enough bite. If you're making metal dust, not chips, you're doing it wrong. It takes forever to do anything and you wear out cutters. I saw a video of someone making a key on a underpowered mill intended for jewelry, and it took an hour to cut a key out of brass. That should take about a minute.
Dremel tools will not work for CNC. The speed drops under load, the bearings wear out fast, and the plastic shell is not rigid enough. I've seen it tried.
> The tech is very close to what's needed for 3D printing but it has a few added requirements like the need for a sturdier frame and accommodations for a fairly large and powerful motor.
This is a huge understatement. You also need large investments in consumable tooling plus metrology tools to do anything useful with metal. The entire operation is really loud, slow, dangerous and throws chips everywhere.
The whole point of the linked article is that CNC machining is a pretty awful fit for a hobbyist! It literally recommends finding alternatives with stuff that's easier to have in a home.
I don't think it's that much of an understatement looking at the table top CNC machine that I got off Aliexpress and upgraded so that it could mill aluminum. Same stepper motors, same Arduino type board, moderately fancier bearings. The main things I had to do were just beef up the frame with some plate and replace the dinky spindle that came with it. I'm not making precision parts with it, just fun hobby things and artsy stuff.
One major difference between 3D printing and CNC is that 3D printing is standardized and simple enough that the steps from a 3D model to a printout are mostly automated. The workpiece is held by sticking to the print bed, print paths are autogenerated and layer by layer.
With CNC, you have to figure out how to hold the workpiece, often with multiple setups (which have to be done precisely), machining strategy (toolpath design) is non-trivial and depends on the exact tools you have (so not trivially automated), and it requires quite a bit of knowledge to properly design a toolpath.
These are all things that I believe can be improved by better software and machines that are designed to teach people how to do it. Current software is still mostly designed for the experts, assuming a whole lot of knowledge exists from before or is built up separately.
Sure, it is aspirational - but at least doable. Others in sibling threads are claiming that CNC machining will never be safe, affordable or approachable due to fundamental reasons. Which I do not agree with.
Semi-related: As an average consumer I'm disappointed that nearly a decade of the "makerspace" has seemingly failed to produce any sort of meaningful Renaissance in small-scale US manufacturing.
I've purchased the odd 3D printed or resin cast tchotchke from small operations a few times at this point. But it's still disappointing that if you need professional quality products, you still either need to pay out the nose to have it fabbed or ship it in from China.
It seems to me the industry is very good at serving hobbyists and prototypers. But I think there is a huge market being missed out on easy-to-use, introductory products for mold tooling, plastic injection, and general manufacturing automation.
As cool as 3d printers can be, I don't think owning one scales up into a professional endeavour very well. However, developing a pretty good mold for a phone case would.
Another problem is that really good CAD software is expensive.
I have used FreeCAD. Its instability frustrated me. Not very rewarding to work on a part that needs a moderately complex feature like a loft, only to find out that after adding the loft FC crashes every few minutes so the part is essentially impossible to edit further.
SolveSpace is much more stable but it doesn't have those complex features at all.
You can use Fusion 360 for hobby stuff, but if you're attached to your work (as any creator would be), it's disquieting to have it hosted in a cloud that you're just being given permission to access. You're one corporate decision away from losing your files.
My dream is that one day some billionaire will buy out Dassault and make SolidWorks free as a form of philanthropy. Imagine what net good could be done for the world with freely available high quality tools for designing 3d objects. Or, to think of it from another angle, imagine how far behind we'd be in software if there weren't any free compilers for "real" languages and the commercial ones cost thousands (per year!)
For FreeCAD, I recommend trying RealThunder's dev branch, which fixes its main topology issues. (They're working on merging but it's a big review). https://github.com/realthunder/FreeCAD/releases
But setting that aside, rather than a philanthropic billionaire, I've long thought big companies like Ford / Boeing / Mitsubishi ought to pool together into some kind of consortium and buy out Dassault to open-source the code. It would probably pay back multiple times over for them -- not through saving on licensing fees, but through all the little efficiency improvements throughout their supply chains. Small machine shops would be able to offer more competitive quotes to customers; more shops would pop up; lead times would improve; file formats would standardize and version mismatches would disappear; new and custom features could get added faster Blender-like; independent developers could write plugins to automate or accelerate mechanical design; new ME hires could gain experience with the tools at home. It would be a huge boon to the industry as a whole. Shame that it hasn't happened yet.
> big companies like Ford / Boeing / Mitsubishi ought to pool together into some kind of consortium and buy out Dassault to open-source the code. It would probably pay back multiple times over
Even though I think SolidWorks is actually worth paying for, your idea seems compelling if you consider how poorly SolidWorks deals with integration, automation, platforms, etc. OTOH it’s probably just a hive of Windows spaghetti, so maybe it can’t really be fixed.
Another thing: there is a lot of purchased IP embedded in SolidWorks, so chasing down IP grants might undermine the prospect of an open source product.
Solid modelling software is very hard to build, and FreeCAD, SolveSpace and OpenSCAD feel like they are built by hobbyists who had heard of CAD but not actually used it talked to anyone who had.
Solidworks for makers was kind of hard to find but free until recently. Now it's $99 per year. Of course, you can't use it for commercial work past a certain point. It kind of seems like it's dying as well, they are going all in on cloud but their cloud product is terrible.
I'm a Mech E (well, originally anyway), do hobby stuff and sometimes I do side jobs. I now use and recommend Solid Edge even though it's not as nice to use as Solidworks. It's free for hobby use, and something like $90/month when you want to use it commercially. You can pay for the license one month at a time.
Solidworks is about $4000 to buy and then $2000 to maintain the license. You can keep using the version you bought, but eventually you have to upgrade in order to work on files with someone else, or to fix a breaking bug, like when 1-2 year old versions were unusable with HiDPI displays. Previous versions get no updates, period. When this happens and you need to upgrade, you have to backpay all of maintenance license fees you didn't pay, or start over again with a new $4000 license.
> You can use Fusion 360 for hobby stuff, but if you're attached to your work (as any creator would be), it's disquieting to have it hosted in a cloud that you're just being given permission to access. You're one corporate decision away from losing your files.
I can export things locally in any format I want from Fusion, is that not the case with certain licenses or something?
Most of the CAD applications have a proprietary source format and can export into more portable formats. I’m not sure I’m aware of a single, portable “source format,” do you know of one?
It depends on what you mean by a renaissance of small-scale manufacturing. I see CNC and 3D printers much more often now in prosumer and small-business shops. People are making professional quality casts, with some work. Yes, it's effort, but it's going to be effort regardless of if you outsource the work, or learn how to do it the right way yourself. Plastic injection machines can be a few grand on eBay now. A very reliable 3D printer is $800, a Shapeoko Pro 4 XXL is $2.5k. Very much in the range of a small business, or even an enthusiast.
I started off with a 3D printer for my shop and that was great for making slipcasting molds for ceramics, and then jigs for woodworking. I bought a CNC for the shop for flattening, carving, and inlaying, and the two have a nice synergy with traditional woodworking methods.
"Maker youtube" has been popping off for years. People love small shops and DIY.
I am specifically thinking of a Christmas bazaar I was just at. You had all of these booths selling beautiful customized phone-cases and earrings and candle-holders and etc. And nearly all of them are starting with Chinese made plastics and putting labor intensive value on top of it.
And there was a single 3d print shop booth that sold glorified paperweights.
It just seemed to me that there is clearly a market failure between these two industries.
Mass market junk is cheaper to make in China and ship by the containerload than it ever will be to produce locally no matter what method you use to manufacture them. Personally I wished people would stop buying these things whose only real goal seems to be to end up in landfills.
Sorry? What I think isn't really relevant. What I see is relevant and what I see is a lot of people making prototype hardware and small series stuff that would be very costly (sometimes impossible) to produce using any other method.
It all depends on where you are looking. You claim - fairly categorically - that 'the "makerspace" has seemingly failed to produce any sort of meaningful Renaissance in small-scale US manufacturing' but that is a complete strawman, it only works if you assume that a renaissance in smallscale US manufacturing was the original goal and that never was the case.
Makerspaces are not even a requirement to be part of the maker scene. Over the past couple of years I've seen elements of it all over industry and in series production up to several 100 units (probably a few in excess of that) of parts that you would have a pretty hard time making otherwise and with such low start-up costs. That you have an entirely different bar for success isn't an issue with the maker scene.
I don't doubt that there are people that end up making things they throw away. But if you're building custom machinery the tools from the 'makerscene' have long escaped the hobby lab and are now a mainstay in any prototyping shop. Tooling, jigs, parts, gears(!), brackets of all shapes and sizes, adapters, custom plugs, cases, scientific gear for lab setups and so on. The list of items I've seen produced with these tools is longer than I care to list here.
There's no 3D components in the cutting boards or wall art itself. I make jigs and spacers and all sorts of things to assist in assembly and manufacture.
An FDM 3D printer is useful for much more than making glorified paperweights. There's immense value in being able to make any jig you can think of, very precisely, and be able to reproduce it in an hour if you need another.
Machining metal in general and, to an even greater degree, mold-making in particular is time and labor-intensive.
Consumers are used to buying injection molded parts at $1/kilogram, with the mold costs largely ignored (by virtue of being <$20K amortized across >500K parts).
They're not used to paying $1-2 per part for just the short-run "soft" mold for a run of a few thousand parts.
I also hold this unpopular opinion : the maker movement has ultimately failed.
I am not fully certain why, but think social factors are partly to blame. What I saw (in the UK) was that the new generation of middle-class, hobbyist makers weren't interested in engaging with and learning from the historical, working-class manufacturing sector.
I know. I went to the wake. After the TechShop failure, the TheShop failure, and the Maker Faire failure, there was a meeting in Sunnyvale where some of the people responsible made excuses. There was a speaker who'd bought the remnants of Heathkit. But they'd gone retro, re-issuing old kits.[1]
TechShop used the business mode of a gym - people sign up, pay a fixed monthly fee, and show up occasionally or not at all. It didn't work. Gyms can get away with way overselling memberships. Most people come a few times a week, max. Usually less. Gym equipment is rugged and not complicated.
None of this is true of a workshop. The people who will pay $100-$200 a month want to use the shop. For some, it's their primary workplace. Machine tools are maintenance-intensive and have many consumables. So the operating costs per customer are far higher.
TechShop, as we customers found out in the bankruptcy, was never profitable. The San Francisco location was said to be, but that's because it was assigned the revenue for the other two bay area locations. The business model was very Silicon Valley - lose money while growing, plan to dominate the industry and eventually make a profit. Didn't work.
It's not impossible to do this, but you need cheap land. This usually means some kind of subsidy, often being part of some publicly-funded facility such as a library or school.
Sharing your "maker experience" with anyone else quickly leads to liability concerns and insurance costs. Someone can injure themselves on your property, despite all you can do to prevent it, and it can still be your financial responsibility. catastrophically so in some cases.
Given that doorstop the "maker movement" hasn't failed; it just hasn't launched into an actual movement. its still a hobby for individuals.
Would you mind expounding upon this comment? Against what goal did it fail to deliver?
I think I was more hopeful a decade ago than I am now that we'd see more decentralized manufacturing and more home-grown innovation, but I'm not sure that these were ever realistic expectations.
I think to OPs comment, tinkers at the turn of the century were able to turn curious scientific discoveries into huge consumer product segments. Radio, film, automobiles, etc all basically grew out of hobbyists at home.
It seems like makers in general focus too much on self-reliance and making personalized goodies than actual creation.
I think the problem comparing to the last turn of the century is the cost of real innovation is much higher (ignoring that most “hobbyists” in that time period were quite affluent). A key difference would be that many foundational technologies were ripe for discovery then, but we are now in the optimization phase.
Founded one with some others in grand rapids, mi 8+ years ago. From a social perspective it was fantastic. But nobody wanted to pay what was needed to even keep the light on. Very few people were making money out of the space. That is pretty much needed to justify 100$+/mo.
> Semi-related: As an average consumer I'm disappointed that nearly a decade of the "makerspace" has seemingly failed to produce any sort of meaningful Renaissance in small-scale US manufacturing.
I don't think this was ever any kind of real goal. Way more emphasis was put on education and removing barriers of entry around design than anything to do with manufacturing.
I largely agree. But I thing the goals should expand.
We have removed the barriers to design and we now have a huge collective competence in design work. But now we have a bottleneck in turning that education into progress.
> nearly a decade of the "makerspace" has seemingly failed to produce any sort of meaningful Renaissance in small-scale US manufacturing.
I think the problem is the constant declaration of the end of manufacturing economies of scale. "Maker" culture should have been focused on rapid prototyping, instead of pretending that the expensive output of 3D printers is sturdy enough to be a final product. "Makers" should be educated about how normal manufacturing processes work, so they can translate their experiments into things that factories could easily and cheaply make.
For me it was a sign that when maker culture was arising, resources for independent engineers (who weren't making kits) actually started to disappear around the edges. The end of the Small Parts* catalog was the worst. Also, instead of using 25¢ micros, people were using $20 full Linux systems to do insignificant things. It seemed like everything was moving backwards.
> It seems to me the industry is very good at serving hobbyists and prototypers.
I don't think it's good for serving prototypers because prototypers should be ultimately thinking about manufacturing as a goal. I don't think that small scale manufacturing is being held back by anything, it's just not efficient and nothing has changed that would make it so.
The domestic production problems/advancement have almost nothing to do with the ease of production itself. The costs still tend to be high because of the high overhead and cost of living. Unless you have huge scale (at which point other manufacturing methods may be more economical) or do it as a side hobby, you have to charge a lot. For a hobbyist, most equipment would be too expensive and take up a lot of room if only using it for a couple projects.
You're wrong. There are massive 3D printing farms that are producing consumer products at scale in the united states now, and that is a direct result of the work that the maker community (both here and especially in China) has done on 3D printing.
Sure. But the vast majority of products are not ever going to be 3D printed.
Most of the things you are going to touch today are going to be injection-molded. Keyboards, keychains, car parts, cups, computer cases, etc.
There's a 3d print shop that sells at my local farmer's market. But they only sell tchotchkes. I am imagining a world where the same size business could also phone cases or mugs or even supply a local manufacturer.
We're not at farmers markets, because our niches are too focused. One guy I follow on YouTube pretty much only sells tool trays for cannabis products and I only sell replacement brake cable guides for 1980's powersport machines.
We've been at the very beginning of what you're describing for about 3-4 years now. I only started selling by request of the communities I'm part of because none of them knew anyone to print it.
> I only sell replacement brake cable guides for 1980's powersport machines
Haha! Doing the Lord's work.
Although, it should be noted that while I buy lots of hard to find car parts this way, as a buyer I almost universally prefer actual molded plastic parts in almost every situation. In some cases I have even requested my money back because the seller deceitfully tried to make their parts look OEM.
I'm actually expanding to Fork Guard Guides in the near future and can appreciate the design differences, all of my stuff is blocky and minimalistic for the most part, and cannot be mistaken for OEM, moreso because the metal brackets are something I simply can't supply with my tiny operation.
I've actually started recommending alternative parts that operate the same, but came from different machines, or even competing manufacturers (like a Suzuki brake cable guide that bolts directly on to a Yamaha but looks nothing like the original).
In the end, this is a product of my frustrations with obsolete parts that become impossible to find. I'm also trying to stay cheaper than the OEM costs of 5 years ago to promote my alternatives ending up on machines that see dirt and rocks on the regular while NOS parts are more likely to end up on pristine restorations. Buying NOS parts for some rough examples never sat well.
There's a (non-critical) switch for my 2000 Honda Foreman that I can't find anywhere except direct from Honda or a dealer and I don't think it's worth the $100+ they want from it. For other model years, I can find it from $20 - $60 which is more reasonable.
I've been thinking of making my own for a while but now you have me thinking of making them for resale. I can't be the only person in this situation.
Ideally you'd print it in PETG, and this can be done on a $100 Ender 2 clone with a $20 spool of filament, but if all you want is a few small parts and maybe a few batches for other people, you could find a local 3d printing service on FB market.
I'm selling a pair of brake cable guides for $10 including shipping to the lower 48. I'll make more money if I find a cheaper way to ship, but I'm not really doing it to make money.
Don't think production floor, think tool room. Every production floor has a bunch of machines that are absolutely not very precise, with an extremely precise insert. The use that insert to make a widget. Over and over and over again. But, there has to be a room in the back of the production floor, isolated from all that, where you make the insert. That's where 3d printers do their work- not the production floor. Because at scale, it almost never makes sense to make things with 3d printers (or ultra-precise CNCs, etc).
3D printing is great for prototyping, and for small production runs, but economies of scale are not in favor of 3D printing for mass production. The material deposition rate is too slow, and the machine cost is too high, compared to traditional manufacturing methods. I have one part that I designed several years ago which is part of the APU installation on a certified aircraft. The part we flew during flight test was 3D printed aluminum (AlSi10Mg). The turnaround time from completing the design, to having a completed, inspected part ready to be installed, was about a week. For a machined part, the turnaround would have been about 6 weeks, and about 6 months for a cast part. But then when we looked at manufacturing methods for the production part. 3D printing directly in metal was the most economical method for up to 10 parts, because there is no up-front tooling cost, but the recurring cost of both the raw material and the machine time is very high. For 10 to a hundred or so parts, the most economical method was investment casting using a 3D printed wax preform, and for more than 100 or so parts, the most economical method was to buy traditional permanent closed-die tooling for the casting.
>I'm disappointed that nearly a decade of the "makerspace" has seemingly failed to produce any sort of meaningful Renaissance in small-scale US manufacturing.
In my opinion, this is one aspect of the modern "rise of the novice". By this I mean, people acquiring just enough knowledge of tools and techniques to make cool-looking stuff, but not enough to make meaningful or useful advances.
I sympathize with your disappointment, but I'm honestly not surprised by what happened. I never expected much to come from it except for introducing a few more people to light manufacturing.
The reason is that the people who were already going to do this (actual mechanical engineers and machinists) had a path forward: buying used CNC machinery and starting up in their garages. And many of them did/are doing this, but it's not the kind of thing that's discussed unless you are on a manufacturing forum, which HN definitely is not.
Part of the problem is that if you're going to make a living doing it, you need professional quality tools that can run all day, every day. "Maker" level tooling won't do that.
> It seems to me the industry is very good at serving hobbyists and prototypers.
Sorta. Prototyping has gotten a LOT better thanks to the resin printers.
Extrusion continues to suck like always, though.
> But I think there is a huge market being missed out on easy-to-use, introductory products for mold tooling, plastic injection, and general manufacturing automation.
Sadly, I simply do not believe that there is a huge market being missed out. I'd love to know what you think isn't being served.
However, in the end, customer service is THE drag on small volume production.
There is a reason why there is nothing in the gap between $100 Chinese electronics things with no customer service (see: NanoVNA) or $10K lab equipment with mediocre support.
What has happened is that services offering medium scales production has become quite a lot more accessible. One can get a quote by uploading to online form, no need to enter a long term supplier agreement, few restrictions on minimum order quantity, and the starting points of prices is lower that before.
And the 3d printer is key tool in prototyping the solution, and validating the design before sendibg off. It greatly reduces the risk of spending money manufacturing the wrong thing, or in wrong way (design issues).
I followed this guide (mostly) and ended up making a reese's peanut butter cup mold out of silicone (from a 3d printed template; I'm not doing anything ultra-precise) and then used my 3d printer to melt chocolate to make the entire confection. It was fun.
This is a great guide. One word of warning: it's not the shop tools that will cost you real money over the longer term, it is the tooling. It isn't rare at all to spend double or more on tooling than you did on your CNC machine, especially if you bought it second hand. So keep a sharp eye out for local machine shops going out of business and ebay to score tooling in quantity, sort out what you think you'll need and sell the remainder. That's going to cost a very small fraction of what you would spend otherwise.
To give you just one example, a pretty common 1/2" dia 3" long quality endmill will easily set you back $40 or more.
And you never have enough clamps and hold down gear.
I wouldn't recommend buying anything other than brand new cutters. People overpay for used junk. New cutters can be pricey, but you only buy what you need anyway.
I use a Shapeoko XXL 3 and 4 and I have a HDM on the way. The 5 Pro and migration to ballscrews for X and Y instead of belts for their more affordable machines looks great. Wanted to first say this is a great resource and I’ll be constantly referring to it. It doesn’t mention Fusion 360 and Vectric Aspire much so I just wanted to add that Fusion is great for engineering designs and CAM but is terrible at machining shapes derived from STL or other high resolution 3D data. Fusion likes you to create the source data in Fusion. It can’t handle creating CAM tool paths for scans with more than 50,000 triangles and even more than 10,000 is asking a lot. Aspire absolutely eats STL tool paths for breakfast and asks for seconds. So for machining topography I’ve moved entirely over to Aspire. I like it so much I’m using it for other non topo projects too because it’s just so fast. It is significantly slower on a Windows VM but absolutely screams along on a modest gaming PC. There’s a free tier for Aspire so try it out. To buy Fusion or Aspire is expensive which is why the guide probably doesn’t mention them much.
Also total tangent but I just installed a Fireboy automatic fire extinguisher above my CNC machine that I use for overnight unattended jobs along with cameras and remote shut off. I’d strongly recommend this for longer jobs. CNC fires are common and seem to be most often caused by insufficient work holding where the part comes loose and is dragged by the bit creating friction and heat.
I watched a good video on the subject of adaptive clearing taking too long to calculate and it helped me to improve the processing and machining time of complex geometry.
Another thing I found with topographic stuff is to simplify the mesh after importing it. It makes very little difference to the final project depending on your scale.
Makes a big difference in quality in my experience and the conversions generally run overnight. Same applies to M1 architecture and high end gaming PCs. I am for example carving the entire state of Colorado on 24” X 24” oak 2.5 inches deep. But I’ve see the same loss on quality on eg a VW beetle relief that I carved that was 24x12”. Aspire has blown me away with the end result and speed of computation.
This is interesting to me; I carved a large model of California elevation using Fusion 360 and an X-Carve. It definitely pushed the limits of Fusion 360, the final model that I CAMmed was 5M (million!) facets and 2.8M vertices and it's just barely usable (rendering, operations, etc all take ~minutes after a change).
Are you saying I can replace F360 with Aspire and it will just do STL meshes faster? Good to know.
I skipped right to the section on CNC machining because that's what I have some expertise in. A couple pieces of feedback:
- In section 2.1.1 there is a note that states "CAM applications are designed to fail safely; that is, if any of the features of the model cannot be reached without plowing through another essential section of the geometry, the problematic region simply won't be machined at all." This is really, really bad advice for someone learning CNC, because it's the kind of statement that may be true 90% of the time but the remaining 10% where it is false can have serious consequences (ruined workpieces, broken tools, crashed machines, injuries etc). Every one of the 6 CAM programs I have used has both intended behaviors and bugs/edge cases that will violate this assumption. A CNC learner should instead be instructed to have a step-by-step verification checklist to determine the correctness and safety of a new program. This includes steps utilizing both the simulation functions within their CAM program and dry running on the machine. In addition to behaviors within CAM, there is a whole additional class of unintended (unsafe) behavior that can emerge once the program is actually run on the machine and will not be caught in CAM simulation. The exact composition of this verification process will vary depending on what you are doing, but the main idea is to never assume your CAM programming will fail safely like this article suggests.
- In regards to Total Indicated Runout in section 2.1.3. The article has a good discussion here, however I would add that the smaller tool you use, the greater effect TIR has on tool longevity and surface finish. As overall tool diameter get smaller, allowable chip load generally decreases. TIR effectively changes the chip load on each tooth as the tool rotates. If TIR is large enough relative to chip load, this imbalance will destroy the tool in short order. Why is this important to a new CNC user? Lots of new CNC operators assume that since smaller tools reduce cutting forces, they can use very small endmills on their benchtop end mills and not worry about rigidity. However, due to the TIR + chipload issue described above, demands on spindle precision actually increase if you want to use smaller end mills. There is a sweet spot where the end mill is cutting, has decent life and does not exert overly high cutting forces, which will depend on the machine and tool holding setup. But this does not necessarily coincide with using the smallest end mill possible.
- In section 2.1.7, jaw chucks (like a drill chuck) should not even be mentioned, except to caution users away from them. The article describes them as if they are just a non-optimal choice, but they are outright dangerous to use for milling. They are not designed to deal with the lateral forces created by end mills. They also are often mounted on tapers that can't deal with those forces either. Please do not reply and tell me you have had success milling with an X-Y table on your drill press. You may have, but you won't be doing it in my shop. It's not safe.
- Section 2.1.8 is overall good info, but misses mentioning what is one of the most important keywords to understanding how CNC machines interface with CAM software: the postprocessor. All G-code is interpreted and comes in many different dialects, with varying degrees of compatibility across CNC controller manufacturers. Which dialect your CAM system outputs is controlled by the postprocessor, which is a build script that can be interchanged to support different CNC controllers. Of special interest to the HN audience is the fact that these postprocessors can be written and (usually) modified, which may be advantageous to support unusual machines or customize your production process. IIRC fusion360 postprocessors are javascript. Professional machine shops without in-house software dev expertise pay big money for custom postprocessors.
If anyone is interested in getting deeper into this subject, I have been curating a list of resources for learning machining on my website here:
I began compiling these because I was mostly self-taught when I started machining and at the time found it pretty tough to find good learning resources that weren't primarily focused on hobbyist-scale machining. These should provide a good introduction to industrial scale, professional quality machining rather than small scale benchtop milling like this article. However, the fundamentals apply to both, so even if your ambitions are small it's good to learn from the pros.
>> First paragraph on article stating "CAM applications are designed to fail safely"...
1000% !!!
That jumped pout in the article. I've gto 15 years doing CAD/CAM/CNC as part of what my shop does for a living have no idea what software he's thinking of.
You MUST be extremely careful with EVERY new toolpath, even after checking the simulation. I verify the zero point, pause and single-step every initial part of each sub-toolpath to ensure it is engaging where I want. After over a decade, I got to pretty much hand-specifying every path and entry, and having an idea of where to check in every new program, and it has been a long time since I've broken a tool or gouged a part.
But the idea that new toolpaths are somehow inherently safe is, well, dangerous.
Wear your safety glasses always and keep your distance. Seeing a half-inch razor-sharp diamond-coated carbide tool break off at 22000 RPM and fly across the shop is not cool (and the $200 lost is not even close to the uncool part).
That said, once fully debugged and I trust a toolpath, I can leave the machine running in the quieter next room for a half hour+ and just listen if any potential issues start happening and intervene then.
This is absolutely NOT 'move fast and break things'. The things you'll break are your expensive machine, expensive tools, expensive materials, and your irreplaceable body parts. It is measure thrice, check twice, cut carefully, and you'll make some very cool and amazing stuff.
Once again the brief period of excitement I had shortly before the closure of TechShop is roused. They very foolishly offered me three months free, and all of the classes I could take during that time, free! I did every class but the CNC embroidery. Completely hog wild.
In my defense, I was primed for it: extensive drafting courses, some engineering courses, the ability to do math with a parametric mindset, woodworking in high school, some focus on material when I was still on an engineering path before switching to physics, and so on. I just lit up and ran about the place like a crazed monkey churning out personalized knickknacks for friends, throwing together little projects, doing a spot of weird art.
All of the spaces are now faaaar away and I miss just banging out strange things on a whim.
Something I'd add to this list is the use of heat set threaded inserts when combined with 3D printing. Rather than create nut-shaped indentations or threading into plastic, you take a threaded insert, and heat it up with a soldering iron and push it down into the plastic.
Cool guide to get started with! I gave it a quick glance and noticed two things I struggled with when I started with CNC work, work holding and feed/speed calculations. Both of these topics are relatively machine dependent, so I understand the omission.
1. This guide is about making the mold-of-the-mold, the mold, and finally the final product. Its at least 3 steps before you get the final piece of plastic, rather than a single step process like 3d printing.
2. I hear that expensive software can help automate this process ("Design Product" -> "Auto build mold" -> "Auto build mold-of-mold"), but software is surprisingly expensive for hobbyists. Expect to be manually designing these molds and mold-of-molds unless you're willing to pay for some rather expensive software. That being said: "Rectangle -> Difference (product-shape)" is a good start.
3. The chief advantage of resin casting is the huge variety of paints and resins available. If you want a flexible material, get ShoreA 40 Urethanes. If you want a silvery material, buy silver pigments. If you want Red, you can buy red pigment. Compared to 3d printing, you have far more material selection (ShoreA soft materials, from grades 20 to 80, ShoreD harder materials from grades 20 to 80, etc. etc.).
4. There's also a "mass production" advantage. You can build multiple molds and "parallelize" the resin casting relatively cheaply. Once you have the "mold-of-the-mold", building 5 molds, and then using those 5x molds 10x each will be faster than waiting 50x iterations of your 3D Printer. Assuming your object is small enough to fit multiple molds inside your pressure chamber, of course.
5. If you are aiming at extruded ABS (aka: professional legos plastic), the mold-of-the-mold methodology is very similar (though made out of Aluminum and/or Steel, rather than Silicone like in this guide). There's still subtle differences between Aluminum molds vs Silicone Molds, but the similarities mean that you have a better idea of the final-final product with a silicone mold prototype.
6. EDIT: 3D printing is also compatible. If you wanted to make the molds or mold-of-molds out of 3d printers, you probably can do that. Its all just "shapes" after all. However, CNC Mills have far better accuracy than 3d Printers, so CNC Mills are just a better tool for this methodology. But if you don't wanna buy a CNC Mill to go through this process, feel free to play with the techniques listed here with a 3D Printer instead.
--------
The biggest issue with #5 are the "shapes" that molds can make. Its much more restrictive than the "shapes" a 3d printer can make. If you design your shape to be 3d printed, it might be impossible to make a mold out of it that builds that shape.
In contrast, if you actually go through the mold-of-a-mold / mold process as listed here, you innately are thinking about the final Aluminum/Steel die that Injection Molders will do. You have much lower chance of erroneously building a product that's impossible to die cast.
IIRC, the main mistake is that silicone molds are flexible. If a corner gets stuck or something, you can just yank it harder and the plastic will come out. Aluminum/steel dies are very rigid. You can't just do that. So if you're "aiming to prototype an ABS Injection Mold / Steel die", you wanna design your mold to "cleanly lift" off a piece without anything getting stuck.
>> you wanna design your mold to "cleanly lift" off a piece without anything getting stuck.
THIS!!
Make sure you have a good draft angle and reliable release agent coating, or a multi-part mold that can come apart at the seams (which does 99.9% mean a flash cleanup step in your mfg process)
With those, it will work great. Overlook it, and you'll have a very tedius cleanup job before your next part, or worst case, an expensive doorstop or coffee table piece.
The information there seems to dismiss a lot of the dust considerations with regard to cncing standard (aluminum, wood, plastic) materials. Other sources online have been pretty scary. Does anyone have any experience or knowledge?
If the CNC machine does not have a vacuum attachment (if it's just a small hobbyist machine) are there best practices? And if it does, is a simple shopvac sufficient or should I be looking at HEPA filters?
It's tough to plan a path toward growth in these skills without sustaining inordinate expenses at each step. I can't afford to become afflicted with Gear Acquisition Syndrome. I've come close to dropping huge sums of cash on tools before discovering, at the last minute, critical reasons that they could not do what I need for the designs I have in mind. Maybe I'll visit a makerspace? Ah, but every one in my area appears to have gone defunct since Covid year zero.
So the journey up to this point has been:
- A lot of reading: not just faffing around with hobbyist blogspam -- full-on MechE textbooks, learning what really goes into engineering schematic diagrams, all that good stuff
- Getting back up to speed with the pencil-on-paper geometry and math skills I've lost after years of doing all my intellectual work in digital form (at least I can still draw a freehand circle)
- Proto-proto-prototyping: just making some physical objects roughly of the same geometry as what I've designed -- whittling them out of wood, sculpting them out of polymer clay
- Hacking together janky tools: trying to make a crappy mini lathe out of Meccano-clone parts, trying to make a crappy mini lathe out of an electric drill, just to get a basic feel for what's involved
- Apologizing to my wife for all this weird scary stuff in the corner of the apartment
I was a CS major. The only hands-on physical engineering I did in college was cooking a single-transistor chip in a freshman applied physics lab. Basically I feel like someone who has studied everything about the physics of bicycles but has never ridden one. I'm really struggling on how to proceed.