[HN Gopher] Guerrilla guide to CNC machining, mold making, and r...
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Guerrilla guide to CNC machining, mold making, and resin casting
(2015)
Author : Tomte
Score : 235 points
Date : 2023-01-11 15:26 UTC (7 hours ago)
(HTM) web link (lcamtuf.coredump.cx)
(TXT) w3m dump (lcamtuf.coredump.cx)
| dekhn wrote:
| 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.
| throwaway4aday wrote:
| 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.
| tgsovlerkhgsel wrote:
| 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.
| digdugdirk wrote:
| 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.
| gaze wrote:
| 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.
| naasking wrote:
| 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].
|
| [1] https://wiki.printnc.info/en/about
|
| [2] https://openbuilds.com/builds/category-list
|
| [3] https://www.makerfr.com/en/cnc/rs-cnc32/
|
| [4] https://hackaday.io/project/176110-multibot-cnc-v2
| dragontamer wrote:
| 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).
| buildsjets wrote:
| 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.
| prova_modena wrote:
| 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.
| bsder wrote:
| > 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.
| prova_modena wrote:
| 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.
| michaelt wrote:
| 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.
| jalk wrote:
| I imagine a circular saw with 1 inch teeth will do far
| more damage to human flesh than a grinding disc
| krschultz wrote:
| The grinding discs shatter. Wear a full face shield.
| datpiff wrote:
| > 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.
| throwaway4aday wrote:
| 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.
| Animats wrote:
| > repurposed wood router.
|
| 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.
| prova_modena wrote:
| 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:
|
| https://www.r-c-y.net/posts/machining/
|
| 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.
| colemannugent wrote:
| >https://www.r-c-y.net/posts/machining/
|
| Great info, thanks for posting!
| pugworthy wrote:
| 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.
| 12311231231 wrote:
| [dead]
| DalekBaldwin wrote:
| 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.
| stu_ wrote:
| 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!
| marmetio wrote:
| > 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.
| Max-q wrote:
| Just buy a Snapmaker. Then you can mill, print and laser cut
| with one small machine.
| dragontamer wrote:
| 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.
| prova_modena wrote:
| 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.
| krschultz wrote:
| 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.
| totemandtoken wrote:
| 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...
| DanTheManPR wrote:
| > 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.
| nick889996544 wrote:
| 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.
| DanTheManPR wrote:
| 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.
| cpp_frog wrote:
| 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?
|
| Thank you for your comments,
|
| M.
| iancmceachern wrote:
| For #2 check out the YouTube series "the secret life of
| components"
| s1artibartfast wrote:
| >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.
| digdugdirk wrote:
| 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.
| Prcmaker wrote:
| 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.
| Rokid wrote:
| > 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.
| nick889996544 wrote:
| (I'm not the parent commenter) in my opinion more along the
| lines of thinking behind "move fast and break things" vs
| "measure twice cut once".
| naasking wrote:
| > 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.
| switchbak wrote:
| 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.
|
| Edit: clarification
| DalekBaldwin wrote:
| 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.
| digdugdirk wrote:
| 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.
| Animats wrote:
| > 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.
| bsder wrote:
| Some makerspaces are still around, for example:
|
| Austin, TX: https://asmbly.org/
|
| Worcester, MA: https://technocopia.org/
|
| Irvine, CA: https://urbanworkshop.net/
|
| 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.
| switchbak wrote:
| I haven't checked into a makerspace in a while, and it's sad
| to hear that's where it's gone (for you at least).
|
| Then again I live in the (relative) boonies, so the closest
| I'll come to a makerspace is what I stick in my garage :)
| donkeyofd00m wrote:
| 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
| Prcmaker wrote:
| 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).
| donkeyofd00m wrote:
| Cool!
|
| I work in R&D in heavy mfg
|
| 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
| Prcmaker wrote:
| 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.
| donkeyofd00m wrote:
| Lol sweet... so even you guys with highly dangerous stuff
| too
|
| Hey, my favourite jank tip: an O ring blew but you don't
| have a replacement? Bubble gum works pretty well for a
| few days
| digdugdirk wrote:
| Okay, but maybe lets not share that particular tip with
| the dude who works on radiation equipment?
| Prcmaker wrote:
| If it gets it through the test, it did its job.
|
| Ratchet straps can be a good insulator, when clean and
| used properly, to higher voltages than you'd suspect.
| digdugdirk wrote:
| This. 1000x this.
|
| 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.
| the_cat_kittles wrote:
| 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
| imtringued wrote:
| 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.
|
| Screw you NVIDIA!
| donkeyofd00m wrote:
| 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!
| takk309 wrote:
| 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.
| georgeecollins wrote:
| I sent this right away to my son that does FIRST robotics. It's
| amazing the tools that he has available to him.
| [deleted]
| dragontamer wrote:
| Notes vs 3d printers.
|
| 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.
| legitster wrote:
| 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.
| [deleted]
| fdsklfdsjkl wrote:
| >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.
| thepasswordis wrote:
| 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.
| legitster wrote:
| 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.
| dekhn wrote:
| 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).
| dicknuckle wrote:
| 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.
| legitster wrote:
| > 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.
| dicknuckle wrote:
| 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.
| buildsjets wrote:
| 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.
| pyb wrote:
| 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.
| h2odragon wrote:
| 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.
| Animats wrote:
| > the maker movement has ultimately failed.
|
| 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.
|
| [1] https://shop.heathkit.com/shop
| tw98521358 wrote:
| Probably the same v reason the internet of knowledge failed.
| Walled gardens, and Soe spam.
| jehb wrote:
| 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.
| pyb wrote:
| I realize my comment is way too terse to make sense to
| anyone other than myself, this should be a blog post!
| legitster wrote:
| 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.
| jwagenet wrote:
| 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.
| vorpalhex wrote:
| I don't want to sell cars or radios. I want to make the
| things I need for myself.
| pessimizer wrote:
| > 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 25C/
| 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.
|
| -----
|
| [*]
| https://web.archive.org/web/20190221190826/http://smallparts...
| bsder wrote:
| > 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.
| giantg2 wrote:
| 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.
| rspeele wrote:
| 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!)
| mitthrowaway2 wrote:
| 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.
| no-s wrote:
| > 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.
| naasking wrote:
| > For FreeCAD, I recommend trying RealThunder's dev branch,
| which fixes its main topology issues.
|
| Hallelujah! Does it fix all cases, or 70%, or...?
| eightysixfour wrote:
| > 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?
| kube-system wrote:
| You can export it... either in a non-source format, or in a
| format that only opens in said cloud.
| dekhn wrote:
| No, you can export STEP to local files, or f3d's. f3d's
| open from the filesystem, so you can send that to another
| person.
| kube-system wrote:
| I'm saying that if you've been kicked out of Fusion 360
| or it no longer exists, you won't have anything to open
| the file with.
|
| As opposed to locally installed software which will run
| indefinitely.
| jwagenet wrote:
| Most professional cad software is behind a subscription
| or license server, so I'm not sure what the alternative
| would be.
| kube-system wrote:
| There's not as many offline perpetual license options
| today, but that model used to be common.
| eightysixfour wrote:
| 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?
| kube-system wrote:
| It's less about the format being portable, and more that
| the software is portable along with the files. You need
| both to be able to work with them.
| [deleted]
| dymk wrote:
| 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.
| RobotToaster wrote:
| >"Maker youtube" has been popping off for years. People love
| small shops and DIY.
|
| People love _watching_ small shops and DIY, not actually
| doing DIY, or paying small shops.
| dymk wrote:
| Disagree, that's not been my experience at all (as the
| owner of a small shop, who was inspired much by maker-
| youtube)
| legitster wrote:
| 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.
| jacquesm wrote:
| 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.
| legitster wrote:
| I mean, what do you think most people are using 3D
| printers to make?
| jacquesm wrote:
| 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.
| dymk wrote:
| I used my 3D printer and CNC to assist in making these:
| https://www.longtailwoodcraft.com/gallery.html
|
| 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.
| legitster wrote:
| Sure. I am trying to limit my comments to the value of 3D
| printers in the consumer space since I know they are not
| without their applications.
| kube-system wrote:
| It's there, it's just... small scale. Mass production
| techniques inherently don't work well for things that aren't
| mass production.
| datpiff wrote:
| > 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.
| legitster wrote:
| 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.
| sokoloff wrote:
| 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.
| jacquesm wrote:
| 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.
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