[HN Gopher] What we learned making a plastic injection mold with...
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What we learned making a plastic injection mold with a Chinese mold
maker
Author : ahaucnx
Score : 500 points
Date : 2023-10-05 23:26 UTC (3 days ago)
(HTM) web link (www.airgradient.com)
(TXT) w3m dump (www.airgradient.com)
| 93po wrote:
| I bought one of their kits, spent a decent amount assembling it,
| and then 5+ hours trying to diagnose it only connecting to their
| dashboard once every few hours, and sometimes not for days at at
| time. Even a replacement ESP didn't fix it. Disappointed that
| it's not really functional for my needs given the cost.
| ahaucnx wrote:
| Please reach out (again) to me [1]. We are just launching a new
| main board with the ESP32-C3 that might fix your issue. Happy
| to send it you.
|
| [1] https://www.airgradient.com/support/
| 93po wrote:
| Thanks, I appreciate that. You/your team were also really
| responsive with the first ESP replacement.
| geokon wrote:
| Out of curiosity, wouldn't it be easier/cheaper/faster to use
| some existing off-the-shelf design and drill/machine some holes
| if you need it slightly modified?
|
| It seems everyone reinvents the plastic-rectangle-with-grooves.
| Is there some obvious reason for this?
|
| And is there some canonical place you can get some proven high-
| quality boxes in bulk?
|
| A friend and I made some sensor boards and used off the shelf
| waterproof enclosures - but I wonder if there is some go-to
| standard enclosures that people go for
| bambax wrote:
| Another approach, for low volume and if the target user can do
| a little assembly, is to make something out of laser cut
| plaques of plywood or plexi. It's simple to make and easier to
| ship (because it's flat until it's assembled). The Ikea way, if
| you will.
|
| I do this for my personal projects (volume < 5) and the results
| are nice and functional. You can also cut holes for buttons and
| whatnot and you get something well tailored for your needs.
| devsda wrote:
| If it can be 3D printed, is (commercial?) 3D printing more
| affordable/efficient for such low volumes ?
| bambax wrote:
| In my experience it mostly depends on the size of the
| piece. Commercial 3D printing can produce beautiful and
| strong objects, but they are size limited and the price
| goes up fast with the size.
|
| Laser cutting can be quite big and make a large volume box,
| if that's what you need. And transparent plexi is nice (if
| it fits your needs).
| starky wrote:
| Machining time is expensive, so at some point it makes a lot
| more sense to just pay for the tool that will produce the exact
| part you want for a fraction of the price. For low volume stuff
| Hammond Manufacturing makes a variety of plastic and aluminum
| boxes for electronics projects.
|
| No to mention, if you want a unique industrial design for your
| product to stand out then you are going to need custom tooling.
| h317 wrote:
| You are right, it is faster,cheaper and absolutely possible to
| take the existing enclosure and modify it. OEM enclosure
| suppliers will gladly add or remove a few openings on their
| design for a few thousand. They will modify or build a new
| mould just for your new product, and it works just fine as long
| as PCB can be designed around their enclosure.
| Animats wrote:
| > Out of curiosity, wouldn't it be easier/cheaper/faster to use
| some existing off-the-shelf design and drill/machine some holes
| if you need it slightly modified?
|
| For small production runs, definitely. There are standard
| aluminum extrusions for boxes with PC boards. You slide the PC
| board in, and provide custom flat end plates with holes for
| connectors and controls. Here's one of mine.[1] The end plates
| were cut on a laser cutter. Here's a supplier in China.[2] For
| small boxes, the aluminum extrusion alone should cost a few
| dollars.
|
| Somewhere above a few thousand, custom injection molding
| becomes cheaper. Amusingly, these are better boxes than plastic
| injection molding, but don't look like consumer products.
|
| [1] https://github.com/John-
| Nagle/ttyloopdriver/raw/master/board...
|
| [2] https://www.alibaba.com/product-detail/CHANGHE-
| electronics-a...
| the__alchemist wrote:
| Yes. Or use a vertically-integrated service like Polycase that
| will do that for you. But you lose the customization of a fully
| custom enclosure, so it's a tradeoff. And if you're doing high
| volume, it's more expensive. Upfront costs are only a few $100
| for ABS; more for aluminum, or if you want full-color printing.
| c_o_n_v_e_x wrote:
| I posted somewhere else on this thread, but if you're planning
| on getting your products certified, using an off the shelf
| enclosure can be troublesome if the manufacturer can't/won't
| provide test samples. We wound up using an enclosure from Bopla
| which we got certified.
| [deleted]
| t-3 wrote:
| Somewhat surprising mold production would even be considered to
| be sent to China. Every place I've been either does their own on-
| site or has a local partner doing the machining. After all, these
| are not mass-produced parts, they're generally one-off with
| dimensions and fixtures designed to fit specific machines and
| materials.
| icegreentea2 wrote:
| How do you iterate on the mold? I've worked at places that used
| local shops for both mold machining and the actual injection
| molding (we were in medical devices), so I never thought about
| that.
| t-3 wrote:
| Rarely, touch-ups were done when necessary to molds in
| production (usually to fix damage caused by operator error,
| but sometimes to add new flash channels or fix other issues).
| AFAIK, iteration is usually kept to the prototype stage with
| aluminum molds and production molds are generally considered
| 'done'.
| proee wrote:
| What are some typical costs for getting such a mold made, and
| what are the per unit costs of the enclosure once it goes into
| production?
| jbgreer wrote:
| Read the article and found myself nodding along. If you work with
| larger Contract Manufacturers, they often have design for
| manufacturing centers that will perform mold analysis and suggest
| modifications. They often have the advantage of having worked on
| lots of different designs.
|
| And even further down the road: make sure to account downtime in
| your production schedule for mold maintenance.
|
| I see others commenting on registration, certification and
| approval matters and I'll only say: do not underestimate the time
| and cost of that for a global product. This landscape changes all
| of the time. One minute a country will accept evidence of an FCC
| filing; the next minute they require in country testing with a
| local authority.
| [deleted]
| the__alchemist wrote:
| It's interesting how for electronics projects, injection-molded
| enclosures can dominate non-R&D/salary costs unless scale is very
| large. Ie, the PCB, electronic components, SMT assembly are
| probably not that expensive, especially with some of the ops out
| of Shenzhen available. Shipping materials, shipping costs to you
| and the customer add cost. Unintentional radiator certification
| adds cost. Intentional radiator certification adds more. All
| these together might cost 10% of the injection mold.
|
| One escape hatch is custom machined and printed ABS or metal
| enclosures, like from Polycase and Hammond. It is limiting and
| forces you to design around the enclosure, but is much cheaper
| for small/medium runs than injection molding. Ie a few hundred
| $USD upfront depending on turnaround time, enclosure size and
| material etc, then not much more than the plain enclosure per-
| unit.
|
| If you are injection-molding, hopefully you can use a 3D printer
| to prototype, but you may still end up screwing up the first (or
| more) mold due to issues highlighted in this article.
| twic wrote:
| I bought a cheap little air quality meter recently. It has a
| power socket and battery compartment on the back. The manual
| says "DO NOT PUT BATTERIES IN THE BATTERY COMPARTMENT, THEY
| WILL NOT WORK". I would guess they reused the case from a
| previous product that supported battery power, in order to save
| tooling costs.
| LastTrain wrote:
| That was an interesting read but sure would have been nice to
| have a cost breakdown, especially since the article made several
| references to cost tradeoffs. How can I understand the tradeoff
| of not hiring a consultant without having at least a ballpark
| idea of the costs involved?
| versteegen wrote:
| My dad was (amongst many other things) a toolmaker who made
| plastic injection molds. These things can be hideously
| complicated, especially if the designer doesn't understand how it
| will actually be built, and as a result he once spent a year on
| one. In his days everything was manual, no CNC, no 3D models, no
| simulations, and probably no contact with the designer to make
| improvements.
|
| He had to cut milling bits with custom profiles to cut custom
| tools such as a series of graphite and copper spark eroder forms
| to cut just some of the corners and shapes in the (paper)
| technical drawings, then repeat for the next ill-advised bevel or
| interior sharp angle or even lettering which is too close
| together to get a milling bit inbetween two letters. Figuring
| that out was his responsibility alone. Instead of computer
| control, he'd have to do something like first create a scale
| model of part of the tool out of a block of plastic, then use a
| pantograph (a mechanical linkage allowing you to trace a shape
| with a pen and have the movement magnified/minified) to copy the
| shapes on a milling machine -- even shapes that seem simple. And
| then maybe throw away (actually, take home as a souvenir) a month
| or two's work if you cut slightly too deep -- these were high
| precision parts. Not because the plastic had to be so precise,
| but because the completed dies are made out of many steel parts
| that have to fit tightly together and slide past each other, as
| you can see in the article.
|
| Considering the ~two months quoted in the article for this mold,
| I'd think a lot of that complexity is still essential despite
| modern computerized machining. I'm sure a great deal of ingenuity
| and many steps are still needed.
| grecy wrote:
| Really interesting, thanks.
|
| Can you provide ball-park costs - how much was your mold, and how
| much did you pay for 5,000 units to be made?
|
| Even if just a rough estimate that would be really helpful,
| thanks.
| iancmceachern wrote:
| I'm not the author but tools I've purchased in the past are
| usually $3-8k for most smaller parts and $15-25k for larger or
| more complex parts from a lower cost/overseas place and lower
| volume tools and much more from a US or European shop for a
| high volume steel tool. Parts are then a few bucks a part or
| less, depending on size and particular material.
| ahaucnx wrote:
| Author here. Our mold costs were in the USD 5k - 10k range.
| Price per plastic part really depends on the weight and the
| material but you can probably assume USD 1 - 4 per part.
| LastTrain wrote:
| Thanks. Does that include all of the professional services
| talked about in the article?
| OldGuyInTheClub wrote:
| Bill Hammack, "The Engineer Guy" explains injection molding here:
|
| https://www.youtube.com/watch?v=RMjtmsr3CqA
|
| Interesting history of a process that's everywhere and invisible
| at the same time.
| c_o_n_v_e_x wrote:
| I didn't see it mentioned, but depending on the type of volumes
| you're working with, you can opt for a more durable, expensive
| steel mold vs a cheaper aluminum mold. The molds wear out over
| time, steel will typically last longer.
|
| For one of our products, we used an off the shelf plastic
| enclosure. Unfortunately, the process of getting our equipment
| certified with an off the shelf enclosure was much more difficult
| than expected. Finding an enclosure manufacturer who would
| support us through certification was challenging.. the sticking
| point was trying to get manufacturers to provide test samples of
| the gasket materials being used.
| xxs wrote:
| The box doesn't appear to have (glass) fiber reinforcement, so
| I guess the mold is Al. The article doesn't mentioned the type
| of plastic being used, either - by the looks of the video PP or
| ABS?
| ahaucnx wrote:
| Author here. We use ASA plastic.
| unleaded wrote:
| How do you decide what plastic to use?
| ahaucnx wrote:
| UV residence, hardness, mold suitability characteristics
| etc.
| xxs wrote:
| (: ASA, the better ABS. I guess it's ok for a mounted
| enclosure. One thing that I consider a test for quality -
| cheap plastic enclosures/shells (esp. shells for tools).
| PC/PA6/PA66/PC+ABS/POM(!)/PP+GF/HDPE all good (esp. with
| fiber reinforcement for PC/PA). I can't recall the last
| time I have seen ASA, aside quick connect garden fittings.
|
| Out of curiosity: what else have you considered as
| material?
| [deleted]
| irjustin wrote:
| Keyboard.io's blog has in great detail, all the problems, wins
| with working with Chinese manufactuerers from wood workers,
| plastic injection, assembly, etc.
|
| Highly recommend it because they give a lot of details and if you
| start from the beginning you can really see how they learned how
| difficult it was in going into the space. The multiple visits,
| quality control, the issues with who owns what, and where they
| lost money.
|
| https://shop.keyboard.io/blogs/news?page=19
| LoganDark wrote:
| Thank you so much for this link. Spent the last 2 days or so
| reading it. Absolutely full of amazing stuff.
| hef19898 wrote:
| Does one of their lessons-learned include to hire proper
| engineers and supply chain peoole with experience in China /
| with Chinese manufacturers? Ideally all the way up to, say,
| COO, and give those people tze necessary authority to run
| things? Because if not, it is just a collection of anecdotes of
| the clueless, a collection that is used for content
| marketing...
| roel_v wrote:
| " it is just a collection of anecdotes of the clueless"
|
| But those are the entertaining ones innit. What fun is it to
| read a blog (like OP) that says 'yeah we hired a bunch of
| experienced professionals and we didn't have any problems'.
| No, we want to read stories of 'so I forgot about one detail
| and the manufacturer completely misunderstood us so I had to
| fly to China and spend 100k to get it fixed and it still was
| 3 months late'.
| TheSpiceIsLife wrote:
| By the time you do all that, effectively moved in to the
| Design By Committee Industry, what distinguishes your widget
| from ACME Big Widget Co & Sons.
|
| And employing all those people doesn't guarantee success, but
| it does guarantee your failures will cost a lot.
|
| You'd probably want to only attempt making something like
| this as a vanity project, where it matters less if you fail,
| and thereby half the fun is navigating the path to success by
| yoursel[f/ves].
| tzs wrote:
| Once you have molds, make sure you control them.
|
| Here's a story [1] of a company that found that the Taiwanese
| plastic company that made its custom parts stopped responding
| after 15 years. They got another one of their Taiwanese suppliers
| to go to the plastic company to see what was going on--and found
| that the factory was now a hotel and the sales office was a now a
| strip mall.
|
| [1] https://www.stlpr.org/arts/2013-07-24/on-chess-the-case-
| of-t...
| sarchertech wrote:
| If you don't have people on the ground how can you control
| them?
|
| Also if we're talking about China and not Taiwan, even if you
| do have people on the ground, how likely are you to win any
| kind of contract dispute?
| dieselgate wrote:
| Cool article, the piece that stuck out most to me is the "mold
| contract" bits about who owns the mold.
|
| Makes me think about early production FRP sailboats and stories
| about Company B purchasing hull mold from Company A when they're
| starting out.
| quasse wrote:
| This is the type of stuff that trips up many Kickstarter / crowd
| funded projects.
|
| "I have a great idea, I'll just manufacture it in China and sell
| it as a product!"
|
| This is a great overview of the process and complexity for *one
| part* of the manufacturing process for bringing a product to
| market and almost all of them are as complex (or more) and have
| pitfalls of their own. Add on wiring harness mfg, PCB/PCBA,
| machined parts, compliance testing, final assembly, QA testing,
| and revision management and then you're about halfway to running
| a successful product business.
|
| From personal experience, the best advice in the article is to
| hire a domain expert when moving into a field you aren't
| intimately familiar with. Employing them for as little as a few
| months can help you avoid several years of very expensive lessons
| as you figure a new process out.
| raverbashing wrote:
| Yeah
|
| How many hw startups start with "we'll just ship an Arduino/RPi
| with our custom module and that's it" heh, that's _very_ not
| ideal for a variety of reasons
| andy_ppp wrote:
| I wonder why with things like this people don't get that it
| involves real experience and expertise to get parts made
| correctly. Surely there are people offering their services to
| avoid these mistakes who have the relevant skills. Making
| things is much harder than software in some really important
| ways, are these computer programmers demonstrating hubris?
| iancmceachern wrote:
| Surely! I'm one, contact info is in my bio
| derefr wrote:
| I would guess that people assume more abstraction layers
| stand between them and the process than there actually do --
| that "getting something manufactured" is more like using PaaS
| than like using IaaS.
|
| Which is, honestly, kind of a reasonable assumption. In
| construction, you hire a general contractor. Why is there no
| manufacturing equivalent of a general contractor? Because all
| such people are too busy running their own successful product
| businesses?
| krisoft wrote:
| > In construction, you hire a general contractor. Why is
| there no manufacturing equivalent of a general contractor?
|
| There are design companies who do exactly this. You can go
| to them with a very generic problem like "design our fall
| shoe collection" or a very specific one "this bearing in
| this gizmo is too noisy, find a better one". They can cost
| an arm and a leg but they get the job done.
| pavlov wrote:
| _> "In construction, you hire a general contractor. Why is
| there no manufacturing equivalent of a general
| contractor?"_
|
| Houses are much more similar to each other than products.
| If you've built a few houses, you can probably find many
| more customers who will want similar houses. Most people
| don't care if their house is essentially the same as
| somebody's on the other side of town.
|
| But a new product must offer something that's not found in
| the existing products on the market. If it doesn't, then
| there's no reason to go to all the effort of getting it
| manufactured -- customers could just buy the existing
| products where all that investment was made already and is
| largely recouped.
|
| So an industrial design product is more like the houses you
| see on the "Grand Designs" TV show. Each of them represents
| a dream and a vision, and usually there's a lot of trouble
| and blown budgets on the way to the grand finale where the
| family finally gets to sit together by the fireplace in
| their unique creation. ("Grand Designs" doesn't show the
| dream projects that fail miserably.)
| RetroTechie wrote:
| _So an industrial design product is more like the houses
| you see on the "Grand Designs" TV show._
|
| In a way it's like forking a software project: the more
| you deviate from what's done before, the more 'pain'
| you'll be in.
|
| What's done before can be re-done by any competent
| builder.
|
| But beyond that, you'll need expertise in different
| fields, to fit parts of a design together in new ways.
|
| No expertise -> project will fail, or be extremely
| 'painful' (like: costly, time-consuming, many iterations,
| result isn't what you wanted, etc).
|
| Enough expertise -> steps in new territory might be
| uncomfortable or include some mistakes, but overall you'd
| know where you're at, where you're going & have realistic
| expectations.
|
| So yeah - nothing wrong with getting some expert help
| when entering new territory.
| derefr wrote:
| > What's done before can be re-done by any competent
| builder.
|
| That assumes part availability, though. There were kit-
| built octagon-shaped homes in the 1800s; but good luck
| asking a builder to build you one today.
| mejutoco wrote:
| > "Grand Designs" doesn't show the dream projects that
| fail miserably
|
| Great analogy, seriously. As a big fan of that program
| (cathartic if you have any real state project going on)
| let me add that I have seen programs in which the house
| is not finished after 8 years; some in which rooms
| projected for kids are not needed because they are going
| to college; and couples that start together, and by the
| end of the program are divorced (or one of them passed)
| by the end of the program. It really puts things into
| context.
|
| Also, my favourite, when 80% of the participants casually
| say they want to be in by Christmas, summer vacations,
| New years next year, and the host smiles and says
| something like (let's see).
| floil wrote:
| And to connect it back to the original post: the moments
| that make me cringe the most in Grand Designs are the
| ones where the owner decides, as a cost-cutting measure,
| to manage the project themselves despite not having prior
| domain experience. Whereas the author of this article
| successfully engaged an expert early on, and saw it pay
| dividends, despite the up front cost.
| bryanrasmussen wrote:
| >But a new product must offer something that's not found
| in the existing products on the market.
|
| how is it then the case that there are multiple versions
| of products on the market that differ very little from
| each other?
| derefr wrote:
| Logistical convergent evolution. You set off to make your
| own thing, and maybe you _do_ make your own thing, at
| first, in a small-batch artisanal way. Then you try to
| scale up.
|
| You subcontract to various manufacturing companies --
| companies _also_ being used by your competitors. Those
| companies have standard "best practice" ways of doing
| certain things, and they tell you that your design will
| be executed a lot more cheaply if they're allowed to
| nudge it toward conforming with those best practices, so
| that they can use standard parts and techniques.
|
| Iterate this three or four times -- especially in the
| context of a company that's plateaued in market share and
| is now all about cost optimization -- and eventually you
| have a version of your product which is indistinguishable
| from your competitors' products. That's what allows for
| the best economies of scale up the pipeline, and
| therefore saves you _and_ your competitors the most
| money.
| pavlov wrote:
| Typically they're either using the same elements despite
| being branded differently, or there's a competitive
| factor in the design that's not superficially obvious to
| the consumer, or the market is so established that
| there's a repository of existing designs that can be
| slightly tweaked to create a new product affordably.
|
| Let's say you want to sell plastic brooms. With such a
| common product, what possible competitive edge could you
| get by creating your own design from scratch? If your
| reason for getting in the business is that you want to
| address a niche or trend (e.g. you want to sell hot pink
| brooms because it's Barbie summer of 2023), that can be
| accomplished with an existing design. It only makes sense
| to create new molds for a broom if you're a corporation
| like Ikea with the massive sales volume that enables
| vertical integration of every aspect of the product.
| bluGill wrote:
| Most people want a house that is the same or very similar
| to others around town. You want to be unique on your
| block but otherwise the same as houses a few blocks away.
| Just enough that you don't try to get into the wrong
| house those first months after moving in.
|
| Houses that are the same as ones across town are cheaper
| as the builder has experience with it and knows the
| tricks to build it with less labor. They also are
| designed with years of feedback about what other like and
| dislike. They don't have weird corners that are not
| usable because after putting things in that is what fit.
| onetokeoverthe wrote:
| [dead]
| derefr wrote:
| You're picturing the residential-construction kind of
| general contractor; but there's also the commercial-
| construction kind: the kind who works for a commercial
| construction company; who interfaces with a property
| developer as client, and with an architecture firm that
| the property developer has also contracted; and then
| either works with an structural engineer working for the
| developer, or for the architecture firm, or with their
| own structural engineers, or all three. All of those
| engineers push back on any impracticalities in the "dream
| and vision" before any of them are willing to sign off on
| it -- where that sign-off is a requirement before the
| general contractor will get to work.
|
| _That 's_ the thing that I would expect here: that the
| firm you'd hire would come with a built-in person to look
| at your design and say "no, this isn't gonna work, try
| again."
| jjk166 wrote:
| > that the firm you'd hire would come with a built-in
| person to look at your design and say "no, this isn't
| gonna work, try again."
|
| Reputable product manufacturers actually do have that
| person.
| exmadscientist wrote:
| > Why is there no manufacturing equivalent of a general
| contractor?
|
| There absolutely are such places. They're called product
| development companies, and I work for one. We do just about
| everything, which is nice for people who like variety!
| derefr wrote:
| I get the impression that a product development company
| like yours is one _too many_ layers of abstraction for
| most small companies to tolerate. It 's a middleman that
| can end up eating your margin. (So: less like PaaS, more
| like a "website builder" like Wix/Squarespace/etc.) Which
| is why, I assume, so many small companies attempt
| manufacturing without the use of a firm like yours;
| rather than the use of a firm like yours being the
| "obvious best practice" for smaller product companies.
|
| When I imagine a company (rather than an individual or
| "brand") that sets out to get a product manufactured,
| what they likely already _have_ -- and so don 't want to
| pay for the redundant employment of -- is in-house IxD
| and general hardware and product engineering expertise.
| This is the type of talent that's easy to hire for in
| pretty much any developed country; so it's who they've
| probably hired at the very beginning of the product
| development lifecycle.
|
| What such companies _don 't_ necessarily have, is 1.
| domain expertise in engineering the specific _type_ of
| product and the parts that make it up (because this may
| be the first time they 're entering this particular
| space); and 2. ground-level "systems engineering of
| logistical pipelines" knowledge of how to best put the
| plants, mills, factories, shipping, etc. of a particular
| region to use.
|
| Big companies like Apple "vertically integrate downward",
| extending themselves into their chosen manufacturing
| region, getting boots on the ground for months/years to
| grow in-house expertise these fields, perhaps headhunting
| engineers and foremen directly from the factories to
| oversee things "from their side" but still local to
| production, etc.
|
| But small companies don't have anyone to send to the
| manufacturing region. They want to draw the line "on the
| ocean." What they _want_ , is to find a company local
| _to_ the manufacturing region, that has taken the sort of
| local-logistics-oversight and part-specific-engineering
| competencies that were developed locally as a response to
| the demands of these big clients, and "struck out on
| their own", white-labelling this capacity as a service to
| be provided to anyone willing to pay for it.
|
| To go back to the "general contractor" analogy, these
| smaller companies are like _commercial property
| developers_ who already have _architects_ and _structural
| engineers_ working for them; who are looking to get a
| design of theirs built in an entirely different country;
| and who are looking for a _construction company_ (that
| employs its own _general contractor_ , who will be the
| property developer's point-of-contact) in that country.
| The property developer's structural engineer can say
| whether the building is safe in a technical sense, but
| they will rely on the construction company to evaluate
| whether the building is _up to code_ for the area of the
| world it 's actually going to be built in; and therefore
| to push back on the property developer to get things
| changed, when the building "won't work" as planned.
| They'll also rely on the construction company to guide
| them toward _materials_ and _parts_ choices that are most
| idiomatic for the chosen area, and most efficient and
| abundant in the construction company 's own supply chain.
|
| I do realize that a product development company might be
| _willing_ to do a lower-level job like this. But the fact
| that a firm like yours _employs_ its own product and
| design and high-level engineering staff (at least, I
| presume), probably means your firm has higher running
| costs than a firm that didn 't have those staff; and
| therefore needs to charge an amount that might be
| untenable to smaller clients who only need that lower-
| level kind of support.
|
| Which, again, leads me to wonder why there's no kind of
| company specifically targeting that "vertical slice" of
| the logistics chain -- being _only_ the gluing know-how
| to bring together on-shore "product developers" who have
| no off-shore experience/relationships, with the off-shore
| low-level manufacturing they need to use to make their
| product real. If a company that was _only_ this existed,
| I would bet that it _would_ be a "best practice" for
| small product companies to use them, instead of trying to
| send their designs off to factories themselves!
|
| And again, I'll state my hypothesis: this glue is so core
| to the value of many of these products -- especially
| lower-BOM ones -- that any company that starts out just
| providing this service, inevitably vertically integrates
| _upward_ until they _are_ a product development company;
| or even becomes a product company themselves. At which
| point they leave the low-margin "cross-shore oversight"
| jobs behind -- or start charging as much for them as they
| do for the full-spectrum development jobs.
| exmadscientist wrote:
| I don't think you can "glue together" anything without
| being a skilled practitioner in that domain. Otherwise
| how do you know what's what, or how to fix the inevitable
| problems?
|
| And once you're hiring skilled practitioners, the space
| you've envisioned for a glue company has been squeezed
| out. We bill by the hour, and we'll do small jobs. Would
| you rather hire us to make your PCB or someone who's
| never soldered?
|
| And as for us hiring that sort of person, they're already
| employed at the contract manufacturers (and unavoidable,
| the CMs don't really like to work without it). No reason
| to duplicate that layer. Understanding the role of CMs is
| critical to understanding modern volume manufacturing.
| Gibbon1 wrote:
| My company had products with custom plastics. For us it's
| just non reoccurring engineering (NRE).
|
| What's to like about outsourcing it. It's parallelizable
| so you can work on your core competency while they work.
| Core competency, this is your angle that allows you to
| make money. How to lose money, working on stuff outside
| that. They get it done faster and without fuckups. And
| the outputs are something you can just give to a
| manufacturer. If there is an issue the two of them hash
| it out not you.
|
| Only thing not to like is the wad of cash you need to
| cough up. But really if you don't have that you're hosed
| anyways. And paying to get revenue coming in a couple of
| months sooner is so worth it.
| hkt wrote:
| Never seen a more appropriate username!
|
| Can you name some companies in the space? I'm curious to
| know more.
| gregsadetsky wrote:
| I remember seeing the name of such a company on the
| credits page of the Playdate [0]:
|
| https://metric-designworks.com/
|
| Looks like a very humble site/company, but then you see
| that they have Teenage Engineering as one of their
| clients, in addition to Microsoft, etc.
|
| When I have dreams of having a cool successful
| kickstarter around some quirky hardware musical
| instrument I'd invent, I definitely see myself reaching
| out to a company like that..!
|
| [0] https://play.date/credits/
| postmodest wrote:
| Their main problem seems to be that they had never thought
| about how injection molding works, but started a CAD path to
| a product that would need to be injection molded. Anyone who
| has built plastic models could have told them a lot of this
| information, and it's a bit surprising that they had to learn
| by doing at that stage.
| leptons wrote:
| With resin 3D printing, I can produce a complex case for my
| product, although at a higher cost per unit than injection
| mold - but with no up-front costs. It seems fairly cost
| effective considering the extremely high cost of making an
| injection mold. I'm not at the scale of needing 100,000 or
| 1mil units though. Right now it's costing me $5 per
| complete case (5 parts, $1 each - it isn't a very large
| case). I can have 10,000 of these cases made for about the
| same price as it costs to create the injection mold. I'm
| nowhere near the scale of 10,000 units right now, but maybe
| in the region of 1,000 units. The cost does get passed on
| to the customer and if I ever get an investor and serious
| traction in the market then the injection mold will sort
| itself out and the per unit cost for my product will go
| down.
| mionhe wrote:
| Not that surprising, unfortunately. I work with lots of
| clients and engineers who assume that 3d printing and CAD
| is all the experience & input you need to move to plastic
| injection. It's actually shockingly common.
|
| I think it's really a problem of not knowing what you don't
| know yet.
| hef19898 wrote:
| +1 on the 3d printing, portong parts from 3d printed
| rapid prototypes to machined / molded / forged / cast
| production parts involves much more work and effort than
| most people think. Including engineers and even
| manufacturing engineers...
| mmac_ wrote:
| Often I see someone who will design something in CAD but
| not think about how the product will be manufactured.
| Design for manufacturing isn't a buzzword.
|
| It happens with both plastic and other type of enclosures
| (metal etc). The better designers understand the
| manufacturing process and build their designs thinking
| about how they will be created in a production line. As
| others have mentioned, most manufacturers will say 'yes' to
| anything you request and charge accordingly. They'll just
| figure it out somehow, but you'll be unaware that you've
| doubled the cost of your part due to a lack of
| understanding of construction.
|
| I guess it happens in other fields as well, i.e. architects
| vs builders in the construction industry.
| m-ee wrote:
| It's not always easy to find a mold wizard at short notice.
| Things in hardware space are more word of mouth and
| relationship based. And as others said you don't know what
| you don't know. I had a (mechanical engineer!) boss who was
| happy to 3D print and ignore mold DFM against our mechanical
| contractors advice until he finally did a mold estimate and
| realized it would cost half a mil to make the current design.
| petsfed wrote:
| A lot of people are saying "hubris" without really drilling
| into what the arrogant mistake is. For the record, I don't
| think its unique to computer programmers, but rather to
| people who solve complex problems for a living, and consider
| themselves, at some level, to be decently smart.
|
| It is very easy to convince yourself that you understand
| something because you read a lot about it, and what you read
| makes intuitive sense. But that is _not at all_ the same as
| actually going out and doing the thing, and solving the
| problem from the blue sky. Dunning-Kruger sort-of describes
| this, but I believe that there 's a multi-dimensionality
| issue where being on the good side of Mt. Stupid in one
| domain makes you overrate your capabilities in other domains.
| Vis the nuclear physicist disputing the official explanation
| of how the buildings collapsed on 9/11, apparently because he
| hadn't gotten to the part of the freshman material science
| course that covered how yield strength decreases with
| temperature.
|
| So articles like this are important, even as they are kind of
| obvious to people who have already learned these lessons,
| because often times it takes learning these things the hard
| way to understand why (for instance) the software is actually
| the easy part of an IoT thingy.
| NegativeK wrote:
| > are these computer programmers demonstrating hubris?
|
| Yes, but not in a way that's unique to programmers.
|
| People often underestimate the effort a job entails, be it
| teaching, sales, programming, graphic design, machining, car
| repair vet medicine, etc.
|
| Most of my career history, when I've heard someone say "ugh,
| department X just sits around all day and occasionally does
| Y", they're assuming that the sliver of their insight into
| department X is the totality of what is actually done.
| spuz wrote:
| I think it's a combination of not knowing what you don't know
| but also the huge amount of exposure we've all had to
| injection moulded plastic products we've all had throughout
| our lives. The ubiquity and low cost of plastic products
| makes it seem that they must not be hard to produce.
| TheSpiceIsLife wrote:
| The first one is hard to produce, the subsequent several
| million, not so much.
| jjk166 wrote:
| Running a mold takes a great deal of skill as well. Right
| now (literally just found out about the issue on
| Thursday) I'm dealing with a mold house that's struggling
| to hold tolerances on a part for a medical device. And
| they're running the parts because our in house team
| wasn't even coming close.
|
| Yeah it's not something you need a skilled artisan to
| actively control, but a lot of technical skill goes into
| making consistently high quality parts.
| negative_zero wrote:
| In my experience, if a company is majority software, it's a
| weird combination of hubris and ignorance that I don't really
| see in other sectors.
|
| I consult on product development and I'd say about 50% the
| time, software majority companies think you are trying to rip
| them off somehow when you try to explain everything that is
| NOT software that needs to be done, what it costs and how
| long it takes (and how important it is to lock things in
| early as you can't just "push out a patch" for a $50,000
| molding tool or that you can't just "slap bluetooth in later"
| and not redo all of your EMC certs).
| [deleted]
| onetokeoverthe wrote:
| [dead]
| asdefghyk wrote:
| How about using a pre certified bluetooth module ? would
| this avoid having to redo EMC certs ? OR make very much
| simpler? Of course there may a "cost penalty " for this
| option ....
| duped wrote:
| > How about using a pre certified bluetooth module
|
| The _device_ is what gets certified, not its parts.
| pjc50 wrote:
| Anyone doing "small" (<1k) runs will be using bluetooth
| modules, but unfortunately the EMC cert is for the unit
| as a whole, at least in the EU. Which makes sense
| technically as the construction of the whole unit matters
| - conducted emissions through the power supply, for
| example. It does make it expensive and annoying to do
| small production electronics, which is why all the stuff
| you might see is "modules" from aliexpress.
| londons_explore wrote:
| <1k units runs tends to get a pass from EU authorities
| anyway.
| pjc50 wrote:
| This has no legal status, it's just that hardly anything
| actually gets _checked_. Conformity is self-reported, so
| either you have to lie about conformity and hope that you
| probably won 't see any enforcement, or do the work.
|
| You can see how well the "regulation but no enforcement"
| regime is working by picking up any disposable vape from
| the street and looking for the WEEE "do not bin" symbol.
| It will probably be there.
| IIsi50MHz wrote:
| Germany is one of those more likely to check. A few years
| ago, our first few units delivered to Germany were
| stopped at customs and sent back for no CE mark (how they
| got sent that way is another matter). So we Made SureTM
| all units for EU had it.
|
| Then Germany rejected again because the "CE" was
| obviously in the wrong style, on a generic sticker (I'd
| warned, but been told "It'll be /fine/."). And German
| Customs said our slip directing customers to our site for
| setup and operating instructions was insufficient. This
| time, they held our units until we sent satisfactory
| documentation.
|
| Finally, we were able to send, but with after a warning
| from Customs that a third error would result in permanent
| bannage and seizure at the border of anything we sent to
| Germany.
| exmadscientist wrote:
| We always recommend radio modules for anything but the
| highest volume new products. It's easy to cost-reduce one
| out (worst case, you just build the module yourself), it
| just takes a bit of cash flow to pay for it. And if your
| product isn't earning any money, then you have bigger
| problems than radio cost....
| negative_zero wrote:
| Yes and no and it doesn't matter :)
|
| Broadly and simplified:
|
| Adding a bluetooth module means that, not only is the
| device no longer "electrically equivalent" (which means
| you are re-certing), but you have gone from
| "unintentional radiator" to "intentional", which means
| you have a different and/or additional set of standards.
|
| A pre-certified module (as in, it has modular approval)
| under FCC means you do not have to test the "intentional
| radiator" part the module PROVIDED you exactly follow the
| instructions of the module supplier AND you don't do
| anything "stupid".
|
| Under CE, pre-certified module isn't a thing. It will
| certainly help you pass from a technical standpoint, but
| doesn't really let you "short-cut" the testing and paper
| work.
|
| Hope that makes sense and gives a rough idea.
|
| _edit_ Apologies for rehashing what others have already
| said. I should have refreshed.
| anymouse123456 wrote:
| So much of our industrial tooling has been optimized for
| mass manufacturing. It's incredible what can be done to
| push unit prices down for large volume production.
|
| Because of the focus on mass manufacturing, hardware is
| incredibly expensive to change. The industry seems to have
| centered around doing more planning up front.
|
| But we (software people), learned 20 years ago (from select
| Hardware companies) that this is backwards. If the cost of
| change is high, and that's where your pain is, change more
| frequently. Mitigate that pain and make it a strength.
| (See: Toyota Production System)
|
| I have a product with an addressable market of something
| like 300 to 500 units per year. That puts me in the
| Defense/Aerospace/Medical area, where unit economics are
| completely insane.
|
| And yes. It does feel like being ripped off when someone
| puts ~30 minutes ($20 max) of Western labor into something
| and then turns around and charges me $800 for the privilege
| of supporting an American company.
| compiler-guy wrote:
| You aren't just paying for a half-hour of time, but for
| someone who knows where to put the X.
|
| "The Handyman's Invoice" is apocryphal in the details,
| but almost certainly true in that something basically
| like it happens all the time.
|
| " The Graybeard engineer retired and a few weeks later
| the Big Machine broke down, which was essential to the
| company's revenue.
|
| The Manager couldn't get the machine to work again so the
| company called in Graybeard as an independent consultant.
|
| Graybeard agrees. He walks into the factory, takes a look
| at the Big Machine, grabs a sledge hammer, and whacks the
| machine once whereupon the machine starts right up.
|
| Graybeard leaves and the company is making money again.
|
| The next day Manager receives a bill from Graybeard for
| $5,000.
|
| Manager is furious at the price and refuses to pay.
|
| Graybeard assures him that it's a fair price.
|
| Manager retorts that if it's a fair price Graybeard won't
| mind itemizing the bill.
|
| Graybeard agrees that this is a fair request and
| complies.
|
| The new, itemized bill reads....
|
| Hammer: $5 Knowing where to hit the machine with hammer:
| $4995 "
|
| https://www.snopes.com/fact-check/know-where-man/
| mejutoco wrote:
| > But we (software people), learned 20 years ago (from
| select Hardware companies) that this is backwards. >
| (See: Toyota Production System)
|
| Ironically, Toyota is moving to gigacasting (large,
| single piece casting) to reduce costs [1]
|
| [1]: https://insideevs.com/news/687481/toyota-new-ev-
| production-l...
| borissk wrote:
| Very interesting.
|
| I guess these giga casts are not very repairable.
| delfinom wrote:
| Reparability hurts profit.
|
| Every collision with body damage fixed by an autobody
| shop is stealing money from our overlords.
| Robotbeat wrote:
| There are ways to repair, but even with more repairable
| methods, labor is so expensive that you likely totaled
| the car if you get to that level of damage.
| tw04 wrote:
| >And yes. It does feel like being ripped off when someone
| puts ~30 minutes ($20 max) of Western labor into
| something and then turns around and charges me $800 for
| the privilege of supporting an American company.
|
| So as a senior expert in your field, you make $20/hr?
| Because I don't know any field that charges by the half
| hour, and I don't know any senior engineers that make
| minimum wage to do their job but maybe you're the first.
|
| That's not including the markup the company would need to
| add assuming you aren't dealing with an independent
| contractor.
| wizzwizz4 wrote:
| I know repair people who charge in 10 minute increments,
| rounded up, with no minimum.
| jsty wrote:
| > I don't know any field that charges by the half hour
|
| Not that it detracts from your overall point, but some of
| the best paid knowledge workers on the planet - lawyers -
| regularly bill out in 6-minute increments.
| toss1 wrote:
| Yes, but while the increment is 0.1 hours, but that is
| not the minimum project size/billing, so you can't
| generally just order six minutes of advice.
|
| Beyond that, just the average documented phenomenon of
| task switching is 20 minutes or 0.3hrs, so your "only six
| minute" project really costs the engineer 0.3+0.1+0.3
| hours.
|
| But sure, if you are in a long-term project (here defined
| as more than an hour or two total), you may see line
| items on your bill of 0.1 or 0.2 hours in a day for a
| quick call or something.
|
| Are you such a knowledge worker? Could someone actually
| describe to you a problem worthy of your consideration,
| give you time to think/calculate, then describe a
| response in only six minutes? Sure, there might be some
| such edge cases, but commonly?
| rvba wrote:
| People who do electrical work are much underpaid when
| compared to software engineers. If you are one of those
| usd 300k FAANG interns you probably dont understand that
| lots of smart engineers rot doing difficult jobs.
|
| Drive to analyze a broken electrical box at customer.
| Analyze what is wrong. Read the schematics. Repair it
| (without getting fried). 15 minute repair. 2 hour drive.
| Zero glory, just a shitty job.
|
| Or exchange something that was manufactured wrong and
| test it. Climb to a wind turbine, open the box. Exchange
| a component. Test it. Climb to another 50 towers to fix
| same problem.
|
| Testing short batches of custom products. The testers are
| paid more when compared to blue collars, but still earn
| shit. Also everyone assumes that they are "factory
| workers" while they program their elecronic testers in
| C++. Paid a fraction of what the FAANG intern earns.
|
| Life is unfair to many many people. Looking at your post
| and above - it feels like you are some guys in IT who
| dont know how hard it is in other areas.
|
| Other alternative are bookkeepers, who run books for
| multiple small customers. Get easy to impossible
| questions about tax law - all day every day. From your
| 200+ clients to whom you provide advice by phone. For
| which they dont want to pay.
|
| A team of few accountants tries to book invoices and fill
| taxes from their clients, while being bombared by
| questions. Often super tough questions. Literally 0/10
| experience for a knowledge worker. Every day.
| themaninthedark wrote:
| >It does feel like being ripped off when someone puts ~30
| minutes ($20 max) of Western labor into something and
| then turns around and charges me $800 for the privilege
| of supporting an American company.
|
| If you are just looking at it as labor then yeah, you are
| going to feel ripped off.
|
| But it is not just labor, it is labor + overhead: Office
| space Tools required for job Paperwork associated with
| the job
| throwaway9870 wrote:
| > I have a product with an addressable market of
| something like 300 to 500 units per year. That puts me in
| the Defense/Aerospace/Medical area, where unit economics
| are completely insane.
|
| I have manufactured in that area and while you are not
| going to be in the mass volume pricing levels, you don't
| have to be in the defense level either. You just have to
| build the product with the right trade-offs and design
| the appropriate manufacturing processes. Few seem to know
| how to do this.
|
| Edit: let me expand. Don't injection mold if you can
| avoid it. Do resin castings or thermo-forming, neither
| require as expensive of tooling. 3D print parts with a
| good material like PC CF. Metal fabrication is easy and
| cheap these days. You can get a shop to laser cut, form,
| insert PEMs and powder coat for very reasonable prices.
| We are starting to get a lot of machined parts from
| China. You can source wire harnesses from China also. Do
| assembly with a small team. Use as much off-the-shelf
| electronics as possible, but don't be afraid to make
| small and simple PCBs if it makes your product cheaper
| and simpler. Leave the complex boards to a vendor
| initially because while they might seem simple to design,
| they can be complex to debug and production test
| properly.
| Robotbeat wrote:
| Xometry or 3D hubs, try the different processes. Also,
| try to make it out of sheet metal and use those companies
| or Sendcutsend.
| fsagx wrote:
| in the US, Regulatory-wise, how would a product be viewed
| that's essentially a raspberry pi in a box? Would it need
| FCC certification at all?
| hedora wrote:
| It likely needs FCC certification because the box could
| accidentally act as an antenna (or the RPi might be
| subject to different regulations than the product).
|
| There are also safety concerns, temperature and humidity
| testing, and so on to consider.
| Waterluvian wrote:
| It's my least favourite part of working in software.
| Majority of peers drastically underestimate how much work
| something takes, and where the finish line even is.
| fsloth wrote:
| Weirdly the reverse is true as well - as a rule of thumb
| hardware companies seem to be abysmal at software (lots of
| industry examples).
|
| I wonder what causes this hardware/software
| incompatibility.
| vijayr02 wrote:
| Dunning Kruger effect at organizational scale
|
| https://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effe
| ct
| DanielHB wrote:
| To have good technical leadership, the leaders need to be
| well versed of all parts of the stack used in the
| products. It is hard to find generalists that broad given
| how much experience and education is necessary to reach
| high enough in each field
|
| Heck even software-only companies have problems with this
| where the technical leadership is, for example, of
| backend background and they completely fail in frontend
| and data analysis fronts while having rock solid
| security.
| simonbarker87 wrote:
| Hmmmm, sounds like my future niche then. I've got a PhD
| in electronics, developed a consumer product and ran a
| factory for 8 years to make it, been in dev for 5 years
| (on top of 10 years of coding) and am now a CTO for a
| software company.
|
| What even would that role be called? I suppose CTO but if
| a company that does HW and SW.
| jrexilius wrote:
| That is a rare combination skillset. And awesome for the
| company that needs it.
| mejutoco wrote:
| I suggest founder/CEO as a title :)
| daelon wrote:
| I have a similar (but less impressive) background, and I
| like to joke that I'm a "full spectrum" SWE.
| aquariusDue wrote:
| Chief Technology Unicorn just doesn't have the same nice
| ring to it.
|
| Also there's T shaped skills and there's you with:
| _________ /|\ / | \ / | \
| / | \
|
| Not trying to be snarky, just trying to point out the
| rarity of such a skill set imo.
| contingencies wrote:
| FYI that is the character for "don't" / "no" / "not" in
| Chinese.
| picture wrote:
| Usually the right slash of Bu doesn't touch the rest, so
| I didn't notice it
| simonbarker87 wrote:
| Lol, I quite like CTU but we are dangerously close to the
| Coding Ninja type job descriptions of the 2010s!
|
| No snark taken, I've got plenty of blind spots in my
| skills so those T stems should be a little shallower
| probably but I've been fortunate to cover a lot of ground
| in the last 15 years.
| kentlyons wrote:
| Having worked at both. Hardware companies treat thier
| software like hardware. They spend a ton of time planning
| and iterate very slowly. It's very waterfall. I think one
| of the key advantages Tesla has is they are the opposite.
| They iterate on their hardware like software. They make
| hardware changes all the time so they can hill climb
| faster. And while Toyota invented TPS they seem to be
| stuck at some local maxima and the scope of changes they
| make with hardware are limited or slow compared to
| software.
| wmf wrote:
| People just assume that the factory already has that
| expertise included with their services.
| jpgvm wrote:
| It is available sometimes (at a price). There are some
| upsides, namely in-house experts are more familiar with
| that specific suppliers processes and capabilities.
|
| Downsides are obvious, they work for the supplier and not
| for you.
| baybal2 wrote:
| [dead]
| exmadscientist wrote:
| The factory can help with a lot of this (if you incentivize
| them appropriately).
|
| The factory can never help tweak your initial concept,
| right at the beginning of development (when it's ~free!),
| to save tremendously on future production cost. _That 's_
| what you hire the consultants for.*
|
| *Disclaimer: I'm just such a consultant, though I work on
| the EE side.
| mips_r4300i wrote:
| This is critical and underappreciated.
|
| Numerous small design choices early on can have drastic
| impacts on the complexity of the mold and how expensive
| it will be.
|
| A simple example: designing your side I/o ports to be on
| the parting line, or move the parting line up through the
| hole centers. Didn't think of this? Now you need a slide.
|
| Deciding the surface finish you want also impacts hard it
| will be. You can hide a lot of flow problems and tooling
| marks with a nice rough textured finish.
|
| Some colors show cooling and flow worse than others.
| Clever gate placement hidden under something hidden in
| assembly makes cooling simpler. Etc, etc
|
| Well worth the money spent on a guru to look at your
| design and provide feedback. (I am not one, I've just hit
| every wall)
| _kb wrote:
| There are. It's an entire domain: industrial design. Just
| like software there's both in-house roles and consultants.
|
| The depth of knowledge required to do it well warrants full
| university degrees in the topic. As with most things, you can
| probably take the autodidact route but be prepared to make a
| lot of mistakes. Also be prepared for those mistakes to cost
| 5 or 6 figures. The ease and almost zero cost of exploration
| and learning from failure that software allows does not
| always map to other domains. This is one of them.
|
| Source: partner is an industrial designer and geeks out on
| plastics, materials science and manufacturing techniques way
| harder than obsessions I pursue. It's literally her entire
| world and she still fucks up occasionally too.
| smoyer wrote:
| Wholeheartedly agree ... 2/3rds of your cost will be the
| enclosure and power supply!
| ahaucnx wrote:
| Author here. Yes I agree with you. Having your own mold expert
| really saves a ton of money and makes things much more
| smoothly. We work with a great engineer based in the
| Philippines. You can contact me [1] and I can connect you with
| him.
|
| [1] https://www.airgradient.com/support/
| iancmceachern wrote:
| 100% a lot of the issues they mote are things you would expect
| to catch in the design phase even with a single design review
| with an experience mechanical design engineer
| ck2 wrote:
| Hoping AirGradient can become a serious competitor to the far too
| expensive PurpleAir
|
| But they cannot compete with the purple network in the USA right
| now.
|
| I've suggested this before but if they somehow partnered with
| WeatherSTEM that could change things in a hurry. Even if they had
| to provide discounted units. WeatherSTEM appeared to have their
| own open database so I think the costs of long-term data storage
| would be avoided once integrated.
| Johnny555 wrote:
| >Hoping AirGradient can become a serious competitor to the far
| too expensive PurpleAir
|
| AirGradient's outdoor sensor costs $155, Purple's is $229, is
| 50% higher price "far too expensive"? From your comment, I
| expected Purple's to cost several times more.
| Roark66 wrote:
| Its a nice article regardless if you're going to manufacture in
| China or anywhere else, but a crucial bit of information for
| China manufacturing is missing. What about IP theft? Does keeping
| your mold make it more difficult for people wanting to make
| knockoffs of your parts? Does moving it to a different plastic
| injection part maker help? Is there anything you can do, or is it
| essentially something you account for when "manufacturing in
| China" and you send them components you don't really care that
| much about?
| ahaucnx wrote:
| Author here. Yes this is a good point but did not really apply
| to us as all our air quality monitors are open-hardware anyway.
| roel_v wrote:
| Just out of curiosity, did you investigate how much more
| expensive it would be to have molds made somewhere in the
| West? Is that even available at all for relatively small and
| inexpensive molds/projects/orders like yours?
| anymouse123456 wrote:
| I made the move from software to building electronic
| products in 2019, and while there are notable exceptions,
| here are some things I learned about Western Industrial
| Suppliers:
|
| 1) They are unlikely to work with you at all unless you
| anticipate high volume orders (thousands at least, they
| prefer 100's of thousands).
|
| 2) Price: Get a quote from a Chinese supplier, double it
| and add a zero.
|
| 3) Lead Time: Get a lead time quote from a Chinese
| Supplier. Add shipping + customs slack. Double it and add
| another 30% for the excuses that are going to come.
|
| 4) Quality: Surface finish, dimensional accuracy, materials
| and process will be poor and no one will care. Refunds will
| be extremely difficult to get with Western suppliers.
|
| 5) Efficiency: The ordering process is usually very
| efficient with Asian companies. Western suppliers will drag
| you through a fully manual quoting process that involves
| days, weeks or months of bullshit back and forth while they
| wait for a slot in their broken production process to then
| rush you into commitments for.
|
| 5) Labor: Many "Western Suppliers" sub everything out to a
| random, lowest bidder in China anyway, even after all the
| bullshit.
|
| 6) There are now some 3rd party service aggregators (e.g.,
| Protolabs and Xometry) that are attempting to collect rent
| on Chinese labor. They charge Western prices, offer Western
| lead times and Western levels of support, then sub the work
| out to random shops in China with poor communication, no
| consistency, bad incentives and unacceptable results.
|
| 7) There are some truly incredible, honest, hard-working
| Western Suppliers doing truly incredible work. If you've
| found one, do not take them for granted (e.g., Digikey,
| Craft Cloud, Adafruit, Sparkfun, Make Augusta, and more).
|
| And of course, YMMV
| vjk800 wrote:
| If all those points are true, why would anyone use the
| Western suppliers? Since they keep on business, someone
| must.
|
| It's interesting that China usually has the reputation of
| producing low quality crap, but somehow they get the
| large scale manufacturing right.
| azurezyq wrote:
| Chinese can manufacturer a wide range of products, high-
| end or low-end. Budget matters. Do not expect high
| quality things if you are ordering for dollar tree.
| h317 wrote:
| Not the topic poster, but speaking from the similar
| experience, the cost can be as low as $4,000 in China for
| the size of these parts. In USA/Canada it would start with
| a $60k minimum, and with a 6 month timeline instead of 1.
| And 9 times out of ten, the local fab is making their
| moulds in China anyway.
| mips_r4300i wrote:
| This is similar to my experiences, the really good ones
| still in the US have heavily specialized on high-end
| boutique orders. They can be very competent but also very
| non competitive for any normal work.
|
| Same with with US based PCB shops. They all want to do
| high dollar ITAR restricted boards for govt contractors.
|
| There is a middle ground. US sub shops that oversee
| captive Chinese operations with their own crew and keep
| you in the loop. This worked well for my personal
| projects and wasn't too horrendous. About 16k for a
| simple design that I could've had done with our work team
| for about 8k. But I never had to fly over, play WeChat
| tag in Mandarin, and I got PowerPoint DFM updates
| regularly.
| ahaucnx wrote:
| Original poster here. Yes this is also what I heard from
| people that did molds in Europe. Much much more expensive
| and takes 4 times as long.
| jannw wrote:
| Smart companies operating in CN seeking to minimise IP theft
| tend to "Own" the mold, and carefully manage its use and
| production - to ensure that there are e.g. no 3rd shift
| production "overruns". Producing the mold separately from the
| factory which uses it is not unknown, as is having a western
| employee tallying what comes off the production line. Molds at
| the end of their useful life (either because the item is no
| longer in production, or the mold is worn out) should be
| physically destroyed, and that destruction verified (angle
| grinder cutting it up is not uncommon - with a western
| staffperson overseeing that destruction.).
| thesaintlives wrote:
| Excellent info! Thank you. Can I ask why it was not possible to
| find a USA mold maker? Even if you have to pay a little more
| surely it is better supporting jobs and prosperity at home?
| Thanks!
| FpUser wrote:
| One of the reasons I've decided on using sheet metal for a part
| rather then plastic injection mold.
| userbinator wrote:
| _You cannot have 90 degrees in your mold. For the mold to exit
| your plastic part, it needs to have a slight angle of a few
| degrees._
|
| This is known as "draft":
|
| https://en.wikipedia.org/wiki/Draft_(engineering)
|
| I'm more familiar with metal casting, but plastic injection
| molding seems to have a lot of similarities, such as shrinkage
| and flow considerations.
| [deleted]
| jdblair wrote:
| This was famously an issue with the original NeXT Cube:
|
| Recounted in an article in Fast Company: As
| Isaacson relates in Steve Jobs, most parts cast in molds have
| an angle that is slightly greater than 90 degrees, because the
| extra degrees make it much easier to get the parts out of the
| mold. That's the kind of compromise neither Esslinger or Jobs
| was willing to make for the NeXT, arguing it would ruin the
| "purity and perfection" of the NeXT cube. So the sides had to
| be produced separately, using molds that cost $650,000, at a
| specialty machine shop in Chicago.
|
| https://www.fastcompany.com/3056684/remembering-the-
| design-l...:
| Kon-Peki wrote:
| > using molds that cost $650,000, at a specialty machine shop
|
| Just because the mold was really expensive doesn't mean that
| the marginal cost of each unit created by it is more than a
| unit produced by a cheap mold. In many cases, the marginal
| cost is significantly less as you are able to use less raw
| material thanks to variable thicknesses, etc. There's a
| break-even point where the expensive mold becomes
| cheaper/better and that's another area where experienced
| manufacturing consultants help out.
| SoftTalker wrote:
| Gave up on that with the first generation of iMacs. Not a
| right angle to be found, all curves and plastic.
| car wrote:
| This was also the case with the 1st gen version of the iPod
| Shuffle [0], as a friend who worked at IDEO at the time
| pointed out. Perfect 90 degree angles.
|
| [0] https://support.apple.com/en-us/HT204217
| justinator wrote:
| The way Lego bricks are injection molded is quite fascinating.
| pests wrote:
| Do say more?
| kubanczyk wrote:
| Engineerguy video from another thread:
| https://youtu.be/RMjtmsr3CqA?feature=shared&t=422
| moring wrote:
| Do you know if this is explained in detail somewhere? Both
| Wikipedia (English / German) and various websites only repeat
| that you need an angle "to lift the mold and to avoid stress
| cracks", but none seems to explain why. (My guess for the
| "exit" part is friction due to imperfect mold/part surfaces,
| but so far I can only guess)
| mips_r4300i wrote:
| Short answer is 3 degrees draft is pretty safe most of the
| time, assuming you have some texturing. A shallower texture
| means you can get away with a bit less draft and vice versa.
|
| The reason is that you want the tool to release the piece and
| not get bound up. Shape and cooling also factor in, but for
| simple box type shapes with no large cutouts, this is usually
| predictable.
| userbinator wrote:
| Yes, friction, also exacerbated by shrinkage during cooling.
| unleaded wrote:
| Engineerguy explains it pretty well:
| https://youtu.be/RMjtmsr3CqA?t=391
| bluerooibos wrote:
| When I was a student I worked for a company who made injection
| moulded HDPE parts for fishing boat gear. After a few years on
| the market, the company noticed identical products coming out
| from China, the only difference being that the parts were far
| more brittle and broke easily (they still even had the company
| website printed into the plastic).
| askiiart wrote:
| It's taking a really long time to load for me, is anyone else
| having this issue?
|
| HN hug of death maybe, now that it got upranked?
| aikinai wrote:
| I was just setting up an AirGradient and was annoyed the site
| was slow as I was referencing some documentation. Then I come
| here and see why!
| lbourdages wrote:
| Mirror: https://archive.ph/TiNXf
| XorNot wrote:
| Anyone know if AirGradient plays nicely with Home Assistant? i.e.
| running local without the cloud?
|
| I've been in the market for a few more CO2/air quality monitors
| around the house, but I'm unhappy with the very proprietary
| nature of the uHoo and it's incredible expense.
| robga wrote:
| I run several self built Air Gradients on ESPHome and they do
| not connect to the cloud - or any external service. Works well
| with HA. Rock solid for 2+ years. I have to reboot them every
| 6-9mo or so if they "freeze".
| a96 wrote:
| "Rock solid" and "have to reboot them every 6-9mo or so" seem
| pretty contradictory.
| ftigis wrote:
| There's this bit in the description:
|
| https://www.airgradient.com/indoor/#:~:text=The%20AirGradien...
| .
| starky wrote:
| Yes, I've got my DIY one working with Home Assistant. It is
| just running on an ESP32 so you can load a configuration to it
| via ESPHome [1].
|
| [1] https://github.com/ajfriesen/esphome-AirGradient
| ahaucnx wrote:
| Achim from AirGradient here. Yes all our monitors [1] work
| nicely with Home Assistant. Especially via ESPHome [2].
|
| [1] https://www.airgradient.com/indoor/
|
| [2] https://www.airgradient.com/integrations/home-assistant-
| esp-...
| montjoy wrote:
| HA has made it really easy to flash the esp chip. You just plug
| the chip directly into your computer for the initial flash.
| After that you can do it remotely.
| londons_explore wrote:
| Is it really worth making a mould for making 500-1000 units?
|
| At those kinds of quantities, I would just fire up the 3D
| printer, and leave it printing in the corner of the office for a
| few weeks (with an auto-ejector).
|
| It would end up costing ~10 cents/part, assuming you already have
| a 3d printer for prototyping and already have someone who knows
| how to load a new reel of filament into it every morning and
| evening.
|
| Thats hard to beat for anything under 10k units...
| Agree2468 wrote:
| They provide .stl files for you to 3d print your own enclosure,
| or presumably order form a third party printer. I assume this
| shell is specifically for those who are concerned with
| appearance and/or fire resistance (PLA is pretty flammable.)
| krisoft wrote:
| So, what is Chinese specific about any of this advice? Every
| single word of this would apply the same if the factory were
| Indian, German, or Canadian.
| exmadscientist wrote:
| You're right, most of this is table stakes for production
| injection molded parts. The part that's particularly relevant
| for China is that they love to own the tooling themselves. Do
| not let this happen. Always either own the tooling outright
| yourself, or do as the article suggests and negotiate a more
| complicated agreement.
|
| The other thing you have to watch out for in China is using low
| grade steel for molds. That might be a perfectly appropriate
| move... so long as it's what you are expecting (and paying
| for). Not so great if you paid for the best and got pot metal!
|
| Both problems exist everywhere but are particularly important
| to watch for in China. The best shops will never do either, but
| it's still better to cut off these entire classes of problem by
| being proactive.
| SoftTalker wrote:
| The way I've heard it put: In China you can get any quality
| of manufacturing you need, but you have to specify it exactly
| and verify it before accepting/paying.
| mips_r4300i wrote:
| This is exactly it. Trust but verify.
|
| Also, each production run is unique and it's own beast.
| Never assume past success will guarantee future success.
| sheepybloke wrote:
| We did some molding and extrusion at a startup I worked at. A
| couple of things from our experience:
|
| - Need to be incredibly explicit. Call out tolerances, how you
| need it to be created, expectations, everything you can think
| of. They'll do the work to what you specify, but if you don't
| specify something, there will be issues there.
|
| - They are as precise as you ask them to be.
|
| - Be careful of prototypes to full orders. We got a lot of
| parts where the prototypes were perfect, but the when they mass
| produced them, the method was different, causing an issue with
| the part.
|
| - You need to be the knowledgeable party of your design. From
| our interactions, they are implementing your design, not
| necessarily helping you make it work. If you don't have a lot
| of plastics knowledge, there will be a lot of issues and
| retooling to get it to work, so I would go with a manufacturer
| that is more collaborative.
| mitthrowaway2 wrote:
| In my experience, there is a substantial difference: the
| Canadian factory never replies to a quote request.
| sfmike wrote:
| Agreed in China they'll respond to anything which is a Pro,
| in USA experience as well has been maybe they'll respond but
| the email will get a casual 1 line response in 2 weeks. There
| are certainly cultural differences between working with China
| versus other places and like anywhere else has pros and cons.
| mips_r4300i wrote:
| Chinese shops will always say yes to whatever question you
| ask.
|
| Can you do XYZ impossible feature? yes! Can you do it for
| cheap? Yes! Etc,etc
|
| The guy at the front of the business will BS you hard to
| get you in.
|
| Later their DFM guy will make subtle, or not subtle changes
| to your CAD files because they realized they have to
| actually make it.
|
| Or, they sub it out and take a cut off the top.
|
| I have seen designs completely reverse engineered and
| recreated wholesale from a step file to fix numerous
| unpredictable features.
|
| The client did not realize this until the tooling was
| already produced.
|
| The YOLO factor cannot be understated. It can both work for
| and against you.
| ahaucnx wrote:
| Author here. We only worked with Chinese mold makers but from
| what I understand there are some country specifics, e.g. it is
| important to define the mold ownership in the contract. But
| yes, a lot of the advise probably applies independent of the
| country.
| TheSpiceIsLife wrote:
| I don't see that being a China specific consideration.
| starky wrote:
| Agreed, this is all just the basics on how an injection molding
| project goes. There is tons more involved in learning how to
| work specifically with Chinese manufacturers so you get the
| product that you require. Things like how building a
| relationship with your vendor being incredibly important to
| doing business with Chinese companies are not covered here.
| xwolfi wrote:
| The experience of the writer. I'm not sure he meant anything
| special about us in China in his writing, he seems to be even
| satisfied working with us !
| giantrobot wrote:
| [flagged]
| [deleted]
| sircastor wrote:
| They either don't know they're not complying or they hope no
| one will notice.
| freddealmeida wrote:
| I have done something similar. I just learned not to work with
| the chinese.
| jprete wrote:
| I appreciate the point about not being 90 degrees because I
| periodically need plastic bins for board game organization and
| the ideal shape is a perfect rectangle of an even fraction of
| both box inner dimensions. At least now I know why all the kits
| for this use laser-cut balsa wood or foamboard with home
| assembly....
| andrewstuart wrote:
| One day I looked around at all the plastics in life - in
| particular looking at the plastic cases of vintage computers, and
| I realised that plastics is absolutely incredible. Often really
| beautiful when you think about it, incredibly precise, with
| beautiful lines and curves.
|
| I've come to find plastics really quite interesting. It's kind of
| a magic material.
|
| And at the same time it's a sort of like King Midas in which
| humanity gets this incredible material but now there's plastic
| everywhere polluting everything. Everything we touch is turning
| to plastic.
| isametry wrote:
| Happened to me with LEGO.
|
| I've been a big fan most of my life and it was / is my favorite
| toy product by far, but only as I got older, I realized how the
| whole system is not just brilliantly designed, but the
| mechanical _execution_ of the parts is at least just as
| impressive.
|
| ...And that it wouldn't be possible without plastics. No other
| type of material could ever achieve such durability,
| flexibility and precision; and that's not even considering
| costs - no other materials _period_.
|
| LEGO is a perfect example of a product designed AROUND plastics
| - not something turned to plastics to lower costs.
| twic wrote:
| > no other materials _period_
|
| I wonder if you could do it with horn. I'm not sure how you'd
| make the hollow bits of blocks. But it has the right sort of
| properties. Relatedly, see:
|
| https://plastiquarian.com/?page_id=14337
| autoexec wrote:
| > ...And that it wouldn't be possible without plastics. No
| other type of material could ever achieve such durability,
| flexibility and precision; and that's not even considering
| costs - no other materials _period_.
|
| Mokulock may not be identical or cost the same, but it's
| basically the same product without plastic. They don't snap
| together or come apart as easily, but I like the idea of it.
| I'd love to see LEGO done in metal too.
| marktangotango wrote:
| Is there a lego inspired solution to industrial design,
| specifically mechanical mechanisms? I have had a product in
| mind that is quite intricate with several possible
| configurations. I personally haven't excercised my 3d muscles
| as much over the years and I find cad with 3d printing to be
| not as intuitive as snapping parts together.
| asdff wrote:
| I had a different sort of event looking at the plastic in my
| life. More like, whats the point of this, other than to save
| the manufacturer costs? I'm convinced there's nothing I own
| thats made of plastic that my grandparents didn't have a much
| nicer all metal or wood version. Not to mention its
| unrepeatable and tends to get brittle with age. So much plastic
| stuff I have is straight up junk that's just going to fall
| apart in a few years. Meanwhile you can have a metal can opener
| thats 80 years old and works as good as new.
| GSimon wrote:
| > I'm convinced there's nothing I own thats made of plastic
| that my grandparents didn't have a much nicer all metal or
| wood version.
|
| Agree mostly unless it's for something that needs to deal
| with water in some way.
| infecto wrote:
| Don't be so down and depressed. This is not in defense of
| plastics but flip it around. If we were still making things
| out of wood and metal the items would be incredibly expensive
| due to the labor and resource cost.
|
| I equally dislike all the plastic junk that is bought for a
| couple bucks that are basically use for a moment and become
| trash. There are also amazingly wonderful things made out of
| plastic that last a long time when taken care of. Heck I
| still have toys from 30 years ago that were made out of
| plastic that are still in pretty good darn shape because they
| do not hit the sun. My rice cooker has a plastic shell and
| has lasted a long time. Same with my difference keyboards.
|
| Be aware of your consumption but don't let it drag you down.
| slfnflctd wrote:
| This may be close to true if you don't have need for much (or
| any) health care.
|
| A large number of modern medical treatments would be nearly
| impossible or prohibitively expensive without plastics,
| mostly for sterile use reasons. These use cases have saved
| countless lives. I'm not sure how you'd even begin tallying a
| count.
| lock-the-spock wrote:
| There's some element of survivor's bias here. You only see
| the items that survived long enough and draw a conclusion on
| all the products they had then. Also the price/income ratio
| for any such item might have been quite different.
|
| Beyond this, metal too has serious resource and energy
| implications. Think mining, smelting, production of the final
| shape, treatment against rust, paint, transport, etc. There
| are many steps, many inputs (notably chemicals and energy),
| and quite some demanding work going into it.
|
| I have no answer to these questions: is it more or less
| resource efficient to produce 20 plastic can openers or 1
| metal can opener? Is it more/less environmentally harmful? Is
| it more/less socially harmful?
| yjftsjthsd-h wrote:
| > More like, whats the point of this, other than to save the
| manufacturer costs?
|
| That also translates to customer cost
| nl wrote:
| This is generally an argument that has merit only if you can
| ignore cost and care completely.
|
| Yes, silk parachutes exist. But there was a reason why nylon
| was revolutionary - it was orders of magnitude cheaper and
| required a lot less care.
|
| > Not to mention its unrepeatable and tends to get brittle
| with age. Meanwhile you can have a metal can opener thats 80
| years old and works as good as new.
|
| Plenty of metal can openers that are rusted, bent out of
| shape, or corroded enough to be unusable.
|
| Plastic only usually gets brittle if it is left in sunlight
| (and not always then). Not sure what "unrepeatable" means in
| this context, but plastic is usually at least as repairable
| as wood or metal by using resin. Indeed, both wood and metal
| is often repaired by using resin based fillers.
| dybber wrote:
| I guess "unrepeatable" was supposed to be "unrepairable".
| userbinator wrote:
| IMHO planned obsolescence and shorter design lifetimes is
| orthogonal to developments in plastics. There's a correlation
| but not causation.
|
| While metals are known for their strength and temperature
| resistance, they are also prone to corrosion.
|
| There are plenty of decades-old plastic parts in continued
| service everywhere, that you just aren't aware of because
| they haven't alerted you to their presence by failing.
|
| One example: https://en.wikipedia.org/wiki/File:Plastic_(LDPE
| )_bowl,_by_G...
| SoftTalker wrote:
| There's also the metal equivalent of plastic: cast pot
| metal. Tends to have flaws, very poor resistance to fatigue
| if it's used in moving parts, pretty much impossible to
| repair when it inevitably cracks or crumbles.
| bluGill wrote:
| Pot metal where the alloy is carefully controlled has a
| long life. However it is often just recycle whatever
| melts into a pot without a care for quality and then you
| have no idea if the alloy will last.
| f_allwein wrote:
| "Just one word - plastics."
| https://youtu.be/eaCHH5D74Fs?si=3HsmyLHcDkg2L8d1
| Kosirich wrote:
| Questions to the author whom I see is reading the comments:
|
| - What is the plastic used for the part (ABS, PC)? - What was the
| material for core/cavity (tool steel)? - What was the lowest
| tolerance on the part? - Were US/EU manufacturers considered at
| all?
| ahaucnx wrote:
| - ASA
|
| - DIN 2738 tool steel
|
| - I don't know the tolerances. My engineer probably knows
|
| - Not considered
| tommiegannert wrote:
| Thanks for sharing!
|
| How did you find your mold maker and consultant?
|
| > It is super important that you review in depth this mold 3D
| with your own expert as sometimes mold makers try to do shortcuts
| that save them money but could create problems later on.
|
| Any examples?
| iancmceachern wrote:
| A lot of these challenges can be avoided by hiring an experienced
| mechanical engineer, product designer, etc.
|
| Many of these things you would expect not to leave the initial
| design phase that way.
| washadjeffmad wrote:
| Just thinking that. Granted our artists have access to a lot of
| resources, but their designs have been trialed in house and are
| functionally complete before engaging engineering.
|
| It's kind of cool that someone can basically walk up to
| manufacturing and still get it done, though. I never would have
| considered that.
| EvanAnderson wrote:
| There's a middle ground to creating a dedicated mold in MUD
| tooling[0]. Your mold is a set of inserts that go into a
| standardized base mold. You get less longevity out of a MUD mold,
| but it's typically much cheaper up front and you can reuse a
| substantial amount of the cavity and insert design when you go to
| a dedicated mold.
|
| I did work for a US contract moldmaker. The amount of knowledge
| about the performance of thermoplastics and metals was really
| impressive. They used some interesting off-the-shelf software to
| do simulations of mold performance, too. It was a fun gig. I
| appreciated the tactile, tangible technology that went into their
| operation.
|
| [0] https://www.dme.net/mud/
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