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Ask HN: Resources for “Learning” Manufacturing?
149 points by supermatt 5 months ago | hide | past | favorite | 72 comments
I have been learning cad with fusion360, and have already designed, fabricated and built a number of small items for my own (personal) use around the farm. To date, this has meant prototyping with the 3d printer, outsourcing laser cutting of steel (up to 10mm thickness) and welding parts by hand. Its been mainly small tractor attachments/brackets/etc.

I am becoming a bit more adventurous with my designs, and have started designing some ideas that would need to be injection moulded to be of any real practical use. There are also some aspects of the design that I believe would need to be rotomoulded to reduce material usage and weight to acceptable levels.

How can I move to this "next level" of prototyping and small scale manufacture? Is this something I can achieve myself with (limited) investment in specific machinery (budget ~15k USD)? Im only looking at small runs - but a number of parts, which I would assume would make more commercial offerings expensive?

Industrial engineer here. I love seeing people get into manufacturing!

I agree with the other points, injection molding would be difficult to get into and is designed for moderately big runs. That being said, I know of a guy who was in a similar position as you with a couple inventions he wanted to bring to market. The quote for plastic injection molds was coming out to low 6 figures, and there wasn't a guarantee they would work the first try, so he bought a 3-axis CNC mill and a plastic injection molding machine for the same cost and could iterate faster and cheaper. He now runs a decent size contract manufacturer in Iowa.

Depending on your designs and interests, I'd suggest checking if your nearby community college has welding classes. They're typically very cheap and professional guidance with a skill like that is invaluable. They may have other classes for other manufacturing skills which you could learn on YouTube, but again professional guidance can be invaluable for learning fast and avoiding poor habits that will hold you back later.

Take a look at the hobby offerings for Inventor and Autodesk if you feel at all limited. I recently tried using Fusion 360 but found the interface confusing coming from using Autodesk in school.

If you have more specific examples of things you're looking to make, we could give more tailored advice. There are tons of manufacturing processes available, each with a range of units and product features they're optimal for.

Back in school the manufacturing professors would have us bring in products if we couldn't determine the manufacturing method and they would help us figure it out.

> The quote for plastic injection molds was coming out to low 6 figures, and there wasn't a guarantee they would work the first try, so he bought a 3-axis CNC mill and a plastic injection molding machine for the same cost and could iterate faster and cheaper.

For small parts, it’s now possible to buy reasonably priced injection molding machines (under $10K) that take 3D-printed (resin, not FDM) molds.

This is the way to learn and iterate. Mold making is not as easy as it sounds, but it can be learned. Once the mold is working well you can CNC machine a soft or hard tool.

Although I have to admit that even in the large scale manufacturing space we have no desire to do injection molding in house. Working with a trusted Chinese injection molding company is extremely cheap these days.

Would you recommend any particular brand of said injection molding machines?

I can't recommend anything personally because I haven't used them.

They're also very new, so they're not as mature as old machines. Older machines are massive and poorly documented, though.

This is one of the more polished micro injection machines: https://www.micro-molder.com/

This one is more industrial but seems better for continuous runs: https://www.apsx.com/desktop-injection-molding-machine

There are also several Chinese vendors offering reasonably priced injection molding machines now, but unless you're well-versed in the art of dealing with these vendors and DIYing your own support, they're not a great place to start.

If you just want to experiment, you can build or buy a manual lever-operated machine for under $500: https://busterbeagle3d.square.site/product/buster-beagle-3d-... These won't be powering any production runs, but if you're only interested in prototyping then they can be surprisingly effective.

I don't know Autodesk but recently have been playing with Fusion 360 (like OP, for stuff for my farm) and coming from a software engineering mindset I can't believe how annoying these tools are... so much fiddling with the mouse and camera angles and positioning and switching modes, to do something that requires precision. Like, I know exactly where my holes need to be, why am I dragging them and stretching them and all this nonsense? I felt like I was using Photoshop or Illustrator.

FWIW I found the same nonsense when doing schematic and PCB layout with e.g. Eagle. I'm running a data bus from one component to another. This is a standard thing since the 70s. Why is the tool making me drag lines and manually connect them and individually label them? In Eagle get the exact mouse end point wrong and it doesn't even connect the components and you don't find out until much later in the process when you move something or try to switch to PCB layout and nothing hooks up. Yes, there's some aggregate bus routing stuff but it's the exception rather than the rule.

I don't understand how hardware and manufacturing engineers can stand these tools. So manual and finicky.

I tried some of the programmatic CAD tooling, too but they also didn't really click with me. But I did notice a plugin for Fusion 360 that adds python scripting, so I might give that a try.

Are you using constraints to position and dimension your holes? (If you know the sizes and locations, you should be.)

I find F360 to be quite efficient and precise at these things.

Make a sketch; make a rectangle. Constrain it until it all turns black (do this by reference to the origin). Drop a circle on the sketch. Click the circumference. Press d. Place the dimension tag. Enter the diameter. Press d again, click the center of the circle. Click the left edge of the rect, drag the mouse up to place the tag someplace nice. Type in the distance from the edge to the center of the circle. Do the same for the Y location.

It shouldn’t feel like you’re dragging and sizing anything manually unless it’s just a decorative part.

I need to follow some better tutorials, apparently.

I've found the Product Design Online's "Learn Autodesk Fusion 360 in 30 Days for Complete Beginners!" youtube playlist quite helpful -- though skip the intro videos to Day #1 if you already have experience: https://www.youtube.com/playlist?list=PLrZ2zKOtC_-DR2ZkMaK3Y...

I use Fusion 360 exactly how you say you want to. Just slap some shit on there and then use dimensions and constraints to actually precisely position everything to match my measurements.

I looked briefly to try to find the ones I watched as intros, but couldn’t.

I will say that I learned a lot by watching James at clough42 do some designs, but I think I’d learned the very basics before that.

Briefly, for functional parts: “blue lines on the sketch are bad” Add constraints until they turn black (fully constrained). If you aren’t sure why a line is blue, drag it and see which degree(s) of freedom it still has and add constraints to those.

Once you have that down and made a drawing, I’d then look at “modify user parameters” to make sketches more easily tweakable (especially if you’re 3D printing or trying to match a bolt pattern that’s somewhat “random”). Almost every drawing I start now starts with defining the user parameters (and then using those as the dimension entries).

This might not be the best “first video” to watch, but it’s topically relevant to help you here: https://clough42.com/2020/07/04/tap-guide-block-ii-fusion-36...

I don’t want to judge here, but, as someone who was well versed in fabrication before I used fusion, I found the model of sketch/constrain/extrude to match well with what I do when I physically make things. It is well suited to the mindset that thinks about the manufacturing method while designing.

Parametric modeling is a godsend for woodworking.

Have a look at OpenSCAD, fully scripted CAD. Worked for me coming from programming. But to create more organic forms I've recently used Shapr3D, especially nice on iPad with the pencil. Easy to use with good tutorials.

I'm the education director at a large makerspace and have some ideas for you.

First, if you'd like to take another step forward, I recommend silicone molding your 3D printed part. You'll need to spend a lot of time sanding/prepping, but you can achieve a surface quality similar to injection molding if done right. Your tooling investment will be well under 15k and you can do small batch runs to test the idea. I've seen some product runs under 1k parts that came out looking flawless and were 100% commercially viable.

You can experiment with the type of silicone you use and the type of polyurethane you pour into the mold. You should be working out all of the question marks here. Things like, strength, durability, weight, feel, aesthetic, and more.

BJB plastics has some great silicone products, awesome customer service, and a number of videos up on Youtube to guide you along. They aren't the only ones, but they sure are a great resource for asking questions.

Hope this helps. Good luck!

We had very good luck using BJB two part polyurethane for low production (<1000 year) large parts. There's quite a bit of process engineering required, but you can get fantastic results, and relatively fast die cycle times, without breaking the bank.

Does BJB have some additives so the PU is non flamable? (ul 94 v2 comes into mind)

I believe they do, although it's not a something I have used personally. They have a pretty comprehensive catalog [1], but like most things with adhesives and resins I would just talk to an application engineer about requirements. Haha, I wish they'd had such a comprehensive catalog when we started working on our parts, because we were left to figure out a lot of it for ourselves.

[1] : https://indd.adobe.com/view/5103906b-5e7b-4b52-9fea-09900d1a...

This. Silicone molding also allows for undercuts and thicker walls (which injection molding cannot do).

The book we used in undergrad (mech eng) was "Manufacturing Processes for Engineering Materials" by Kalpakjian and Schmid.

Not convinced it's the best, as I didn't really enjoy the class, but that was mostly due to a poor lecturer. I'm also not convinced that it's the most relevant for you, as you seem to be looking more into "small batch prototyping", rather than mass scale manufacturing.

Still, it's a good book for getting an overview of what is out there in terms of processes and figuring out what would be appropriate for your needs. It's not a good book for getting into the nitty of, say, injection mold design, which is highly specialized.

I do believe Protolabs offers small batch injection molding for "reasonable" cost, probably as reasonable as you'll get for small batch. From my memory they also have a design guide PDF that you can download or they send when you register. That's probably a good place to start. Also try searching reddit r/mechanicalengineering for "injection mold" and similar queries, I do remember a few people asking for resources and getting good replies.

As someone with a mechanical engineering background, i feel that a sensible path to covering the basics would be to take an online course in manufacturing and materials. There is so much more to manufacturing than printing and injection molding, but you will have to design with the process in mind.

For metals alone you have several "chapters": milling (in several axes) Sheet metal (cutting,bending) Welding (in so many ways) Forging Casting (different processes) Brazing Sintering (for special cases) Etc..

My prototypes are usually made by using off-the-shelf brackets, profiles, fasteners etc where the most complex tools you would need are just for cutting, drilling, and tightening bolts. You may find that you can't get around needing a weld sometimes... Usually you can find local workshops that can weld simple Al or steel profiles together according to your drawing. Note: their feedback and experience is usually worth a lot (and given to you essentially for free when you order work).

Best of luck.

i kinda of disagree. i would certainly try to pick up basic welding and machining in the background. you shouldn't be thinking of this your future full time job, but its immensely useful to understand the processes involved intuitively.

posting really to highlight this recommendation of trying to get involved with a local small-volume fabrication shop. you should be prepared for a certain amount of rejection (you're unlikely to represent a good return on time for these people), but if you can establish a good realtionship they know _alot_. not only will you learn an immense amount about processes and materials and costs, you'll learn about how to deal with that whole world.


I think it would be unreasonable to expect much more than an intuition from an intro course. But you make a good point. :)

>Its been mainly small tractor attachments/brackets/etc.

You're going to have to be specific as it is entirely up to what you are manufacturing. How tight are your tolerances? Is it plastics? Metals? By small scale do you mean a batch of 10, 100, 1k, 10k?

There are first class machinists on YouTube that will teach for free and to be frank, I've yet to run into anything that couldn't be machined with a bit of skill, a lathe, a drill press, and a milling machine, all of which you can pick up on the cheap. I'd start there. What about it makes you need to use injection molding? That's a process used in bulk production. If it's tractor brackets and such then casting might be a better idea. If you're looking into injection molding, you'll have to get in contact with professionals - the tooling is in the range of hundreds of thousands if not millions. The "next level" of prototyping for you I think would be machining, not IM. You might be able to pay a contractor to do IM for you but it'd be a stretch at your budget.

On a tangential note, I'm currently working my way through MIT's "Principles of Manufacturing" MicroMasters program on edx and would thoroughly recommend it. It's more large scale systems then anything, but it's been great for me in terms of learning the vernacular and has helped me better communicate with manufacturers when I'm looking to scale one of my designs. Might be worth checking out.


> I am becoming a bit more adventurous with my designs, and have started designing some ideas that would need to be injection moulded to be of any real practical use.

Your wording here is a bit odd. Injection moulding is mostly a question of scale. Do you need to mass-produce your parts or are you just looking for mechanical properties that a standard 3D printer can't provide?

If it's mechanical properties, there may be other options like resin printing, casting or machining parts.

> How can I move to this "next level" of prototyping and small scale manufacture? Is this something I can achieve myself with (limited) investment in specific machinery (budget ~15k USD)?

You can get a (very) low end injection moulding machine for a bit over $2000 [0] and you can get a small desktop CNC milling machine for just under $3000 [1]. I would think about going for something more like a Tormach or SYIL but those are more like $10000.

You might also find Physics Anonymous' videos interesting. They bought a small injection moulding machine for a small run [2].

But there's going to be a huge learning curve here. Moulds are much more complicated mechanisms than static welded parts.

Before you get too invested in injection moulding, I'd really spend some time to see if you can manufacture the part some other way. Maybe talk to a job shop and ask them if they think they can fabricate it.

[0]: https://www.techkits.com/products/model-150a/

[1]: https://shop.carbide3d.com/products/nomad-3/nomad-3?variant=...

[2]: https://youtu.be/n7JWPxk92fY

Injection moulding is still somewhat out of reach for small guys like us, although there are prototyping services offering it now.

The problem is the tool cost vs. small production runs. Plus, designing good tools can get really tricky.

Here is what I would do on the garage scale:

* A CNC router like shapeoko or x-carve (you can buy or diy)

* This allows you to build large, but rather flat moulds

* Pouring epoxy resin mixed with e.g. cotton flakes or other additives gives you nice solid objects

* Laminating glass or carbon fiber can net you large surfaces

* Vacuum forming also nets you large surfaces and can be done with a diy machine

Old, used machines are also always a good idea.

Dragon Innovation has a number of good videos on manufacturing: https://www.youtube.com/watch?v=i0JdkHIkL7I

It appears the company may be defunct, but the information is pretty good.


Edit: It looks like they were acquired - https://ir.avnet.com/news-releases/news-release-details/avne...

There is "Building Prototypes" [1] series by Dan Gelbart on YouTube which is pure gold for anybody that wants to learn how building mechanical things, mostly precision/instrumentation things.

Part 12 for plastic forming and casting.

[1] https://www.youtube.com/watch?v=xMP_AfiNlX4&list=PLSGA1wWSdW...

There's a great course by MIT on all types of manufacturing. It's good overview https://learning.edx.org/course/course-v1:MITx+2.008x+2T2021...

Edit: And also there's a textbook which covers pretty much every method of making things:

Kalpakjian, S. Manufacturing Engineering and Technology.

Join a makerspace if you live near a substantial one. Mine (Protohaven in Pittsburgh) has both a CNC mill and a Morgan injection molder (a rare small injection molder good for 100s of parts), which is a nice way of exploring some tech before buying it. Even more valuable are the people who hang out at these places, who have probably done the things you’re considering.

If you're not making thousands of parts, injection molding is the wrong manufacturing method.

You might be able to buy an injection molding machine for pretty cheap, but it's useless without the appropriate tooling which costs a fortune, and the learning curve for operating an injection molding machine is very steep. If you don't have the equipment and skill to machine your own tooling then trial and error is going to be real expensive - I'd definitely invest there before trying injection molding yourself.

I would recommend calling up a chinese injection molding shop and having them run your parts instead - they have the experience and volume to produce tooling quickly and (comparatively) cheaply, and that's all you really have to pay for. You could always go through the trouble and expense of producing things domestically after you've validated your design. The one downside is that they'll usually just make your design as is, whereas a domestic shop will usually assist you with some design for manufacturing to make sure you get something that actually works for you, but the cost is so high its still often better to screw up a few times with the chinese shops, and nowadays some of them are better with their customer service anyways.

But for short runs you really should consider alternatives. The appropriate one depends on what you're making. Urethane casting is great for making plastic parts with tolerances comparable to injection molded parts - you can even use 3D printing to make the master molds. CNC machining is also very economical for short runs.

"Mastercam University offers 24/7 access to online courses and certification exams to anyone looking to begin a career in CNC programming or to current Mastercam users with the desire to sharpen their job skills. Regardless of skill level, there is a Mastercam University class able to strengthen user knowledge of most Mastercam products." https://university.mastercam.com/

You might price out some of your designs with a lower cost, quick turn, prototype focused injection mold contract manufacturer before deciding that's the right tech for your next projects. Something like ProtoLabs https://www.protolabs.com/services/injection-molding/ or similar.

Even with aluminum molds at a low cost focused prototyping CM, which are MUCH cheaper than steel molds, I think the pricing for just one set of tooling is going to exceed your $15k budget.

Finding 3D printing contract manufacturers who can manufacture with the materials you're interested in would be my recommendation if you're moving into plastics. The unit cost is going to be extreme compared to injection molding, but there's almost 0 tooling cost, so for prototyping 1 or 2 units will be significantly cheaper. Advanced 3d printing these days can rival (or even exceed) the performance of an injection molded part.

>Even with aluminum molds at a low cost focused prototyping CM, which are MUCH cheaper than steel molds, I think the pricing for just one set of tooling is going to exceed your $15k budget.

It really depends on where you go. I've got vendors in China that could easily do 2 dual cavity production tools in that budget.

Injection moulding is very demanding, if you're doing this commercially I would outsource that as much as possible. Unfortunately the economics skews towards high minimum order quantities (e.g. 1000).

A lot of manufacturing knowledge seems to be "oral culture". Finding a local contract manufacture firm to partner with might be a good next step.

For injection molded parts you could start by paying a local consulting firm that specializes in mechanical design to take a look at your part. They will probably be able to help you find a manufacturer and your design will have to be verified by somebody who does this for a living one way or another if you want it to work after a reasonable amount of iterations (better not forget those draft angles). You could also directly ask a local manufacturer of injected parts, as they will have engineers that can help you, but they might only want big customers. Also, that might close doors if you want to move production overseas.

Depending on the size and complexity of your part might just make it for $15k to get the tooling done. The manufacturing itself most probably will never make sense to do inhouse.

It’s a tough question because manufacturing equipment is just stupidly expensive (a good end mill can upwards of $500) and usually out of reach for the average consumer. But if I had 15K to buy equipment I would probably buy a CNC plasma cutter and a Tormach PCNC. But if your budget is 15K, you need to save at least 5K of that for material and consumables. Especially if you’re trying to scale, you’re going to have to account for rejects.

If you want to learn more about manufacturing techniques , this is the book I used in college which had a great breakdown IMO https://www.amazon.com/Fundamentals-Modern-Manufacturing-Mat...

This is less a technical recommendation and more of a fundamental one, but I always recommend that people read The Goal by Eliyahu Goldratt when they're first getting into manufacturing. It is a high-level overview of the principles of effective manufacturing at various scales.

I haven’t fully checked this site out, been saving it for when I run out of runway with my 3D printer, drill press, saw and SendCutSend. Hope it’s useful for you.


I'm a physicist in R&D, so most of my fabrication is for one-time or very small run prototyping. But I work adjacent to a real engineering department and am a technical resource for them. I also have a side business making a little electronic gadget for a certain hobby.

A lesson I've learned is: Never assume you know the cheapest / best way of making something. I've especially learned this from designers working in China, who have surprised me many times because they know their local industry way better than I do.

Some techniques to keep in the back of your mind are punched and folded sheet metal, cast / molded aluminum, and vacuum forming. "Soft" mold tooling is cheaper than hard tooling. Vacuum forming is done with wooden molds. There are now some aluminum alloys that can be used for injection molding with short lifetime, but cheaper to machine than hard steel.

Injection molding has a steep learning curve because of the cost of tooling plus issues such as mold flow, ejection, and shrinkage during cooling. You don't always get it right on the first try.

Look for raw materials and parts that are close to the net shape that you want, and only need finishing or modification. For instance, "plate with holes" can be done with plates cut to size by a raw material supplier and drilled using a plywood jig with carbide drill guides.

Try to attend the International Machine Tool Show when the pandemic cools down a bit. Just for inspiration. Bring good shoes.

My recommendation looking at it from the side and personally as an amateur without inside-scoop info (and without exact info on what you're building) is to look at sheet metal. 10mm thick metal, cut into various shapes and assembled with off the shelf parts like bolts can do a whole lot more than we give it credit. The benefit is that you could probably find local laser-cutters that could do small runs of cutting the pieces for you without the big cost of milling or injection molding.

Personally, the biggest hurdle for me is "finding" the cost of some of these processes so that I could adapt my idea and material early on. All places in my local area require you to submit a formal quote and plans without giving you an indication at all of how much it'll cost (which is inside info that people who use those services often know).

Oh and don't get sucked into the trap of ordering runs from Alibaba, even though you will find someone that does what you need at a cheap price there. It's a pit of time sifting through spam and incorrect info till you find a good reliable supplier, so rather deal with local providers in your area.

I would look at water jet as well as laser. there are just more of them in my area and they are a little cheaper

Depending on what you are making, a local manufacturing job shop or small scale contract manufacturer may be the way to go. 15 years ago during/right out of college, I worked as the software dev/IT department for a company in Central Kansas (http://www.grainbeltsupply.com/) that would be an ideal partner for you on something like this. I don't know where you are, if they still would be (live in different state, haven't talked to anyone there in about a decade), etc, but everything you are describing sounds like the kind of thing a job shop like GBS would be helpful for manufacturing the kinds of small scale production you seem to be talking about. Searching for "fabrication job shop" with your city/region should get you a number of google hits for places that would be helpful.

Speaking solely from what I have observed being on the IT side of two manufacturing companies, your budget for machinery investment is probably an order of magnitude low. Probably want a partner to start.

There are some pretty impressive online fabrication houses to look into that can help you work through manufacturing process options: Fathom, Stratasys-direct, Protolabs, ICO Mold, Xometry

If you want a DIY approach to producing parts you could think about casting polyurethane parts in Silicone RTV molds from a 3D printed buck. This is something you could do at home without much extra support hardware, maybe just a vacuum chamber. Check out Smooth-On (smooth-on.com).

You mentioned rotomolding which sounds like you are looking for large parts. Because of the high cost of rotomolding tooling I would recommend looking into fiberglass construction for dimensionally large short run parts. If you can find a local CNC shop you can have foam bucks machined and then take them to a fiberglasser to create a run of parts or one-offs. DIY fiberglassing is also very possible on a reasonable budget.

For most molding processes you will need to get familiar with draft angles, part lines, minimum wall thickness, sprue placement, etc. These are things that will have an impact on your parts during the design phase.

Very generally speaking on manufacturing, it is good to get into the habit of defining your budget, how big the parts you want to make are, how many you need and what material you want them in. As you answer those questions the better fabrication methods for a part will become more obvious.

Final (and probably unpopular) piece of advice; I would stay away from buying a CNC machine or other large equipment until you know exactly what you need. If your goal is to make finished prototypes and products then it's usually better to spend your time understanding the various manufacturing methods vs learning to be a machine operator for a specific process.

Good luck!

Tangentially related: I watched YouTube videos where some dude builds stuff* in his garage using various tools and substances, and I can't help but wonder, where can I learn this thing?

To paraphrase: How/where do I start, as software engineer, to learn hardware, but not necessarily "computer" hardware?

*Not only limited to woodworking, they also build contraptions of some sort.

YouTube is a great resource for this. There are countless "maker" channels out there. Even channels and video that aren't explicitly "how to" oriented are great ways to learn.

As an example, Adam Savage's "One Day Build" videos on the Tested YouTube channel are a good place to pick up idea for various techniques using a wide range of materials. You're probably not going to go out and replicate any of the specific builds, but it's a good way to build a mental library of ways to accomplish stuff.

That is just one example out of literally hundreds of good options. Along those same lines, channels like Simone Giertz, Laura Kampf, Evan & Katelyn, etc, etc (this list really could go on forever).

Are there specific projects you have in mind? Really the best way to learn is to not be afraid to try. Accept that you're probably not going to nail it the first time, and will screw stuff up along the way, but that's how you learn.

You're right, but what I want to know are the basics.

To give analogy in software development, I don't want to know how to build an app, I want to know what are the tools to build the app and why.

E.g. use IntelliJ for text editor because it's an IDE (Why IDE is important? Why not Notepad?), use Ngrok for tunnel (why?), use Charles for proxy (why?), use PostgreSQL for DB storing relational data (why? what's relational?), use Redis for caching (why?), etc.. you get the idea.

Yeah, that's what I'm suggesting. Most of the channels I mention (with the exception of Evan and Katelyn) tend to start with a problem, and then walk through the choices made why solving that problem (the "how" and the "why" for each "how").

In my experience, what you're asking about is such a broad space there isn't one "thing" or even category of "things" that apply universally at a fundamental level. Getting good at making stuff is all about building up a broad catalog of options for tackling problems and building up the experience to be able to pick the right technique (or know when the

As an example, I was doing some DIY plumbing over the weekend. We were replacing the flooring in a bathroom in our house and when we removed the toilet we found that not only was the flange that mounts it to the floor totally rusted away, but the plywood on top of the subfloor was in pretty rough shape for a few inches around in every direction. I've never done anything like that before, but by leaning on various techniques I've watched people use in various YouTube videos over the years, I was able to effectively repair it (after calling a friend of mine who does have experience as a plumber to make sure my idea was reasonable).

Probably the most useful technique I used in that project was some approaches to pattern making (since I had to make an oddly shaped "ring" or plywood to fit around the drain) I learned about while watching a YouTube channel about rebuilding a wooden sailboat (https://www.youtube.com/c/SampsonBoatCo). That had nothing to do with plumbing when I watched it, but it was a useful approach that I was able to call upon for a more generalized problem. I think that's what the vast majority of "making stuff" is.

If there are more specific things you have in mind, then there may indeed be specific resources about how to make those things, but it sounded like you were asking a much more general question about making stuff in general.

Are you able to provide some additional context? 1. Can you please provide some links to the videos that you're interested in?

> I want to know what are the tools to build the app and why 2. Are you interested in the fabrication and assembly of something (someone gives you blueprints and you gather and assemble the widget) or are you interested in going from I have an idea to I have a finished product?

3. Do you actually want to build something or just have the knowledge?

I would like to introduce you to The Crafsman on YouTube.

He covers the questions in your last paragraph, specifically for small runs and low budget. Even lower budget than you're thinking, so it's a perfect starting point.

Plus he's a hell of a lot of fun to listen to and the production quality is too sweet.

Start here: [0] Making silicon molds

[1] Cheap plastic injection molding using silicon molds + metal casing

[2] Making a complex toy with DIY injection molding

[3] Bonus: the best dubbing of a classic Star Wars scene you've ever seen.

Enjoy! And keep on steady craftin'.

[0] https://youtu.be/RC9TgAO5mGo

[1] https://youtu.be/78bM615koOo

[2] https://youtu.be/lmX5XHtr2jQ

[3] https://youtu.be/VzlkSjFXRlM

The swedish website: https://www.manufacturingguide.com/en has a learning data base of different manufacturing techniques, however not all entries are translated to english.

Fusion 360 is mostly for amateurs. Inventor or some other package that handles SKUs, BOMs, assemblies, static and dynamic analysis, finite element analysis, and other simulation modules is what most MEs use in the real world.

Terminology is important.

Manufacturing is usually outlined by Industrial Systems Engineering for setting-up assembly lines.

Design for Manufacturing (DfM) is an engineering approach to reducing costs and manufacturing complexity of products.

These comprise different areas of responsibilities.

There is no single, universal answer but there are important questions to consider. At what scale? What are you making? What is the current cost per unit? What is the cost per unit target? How much would it cost to build it using powder-sintered FDM?

There is an amateur car builder in Germany called BMW that uses Fusion 360 for generative design https://www.autodesk.com/autodesk-university/class/Generativ...

Don't listen to this guy, or any guy who starts by calling any tool "for amateurs".

"Real" MEs use Fusion 360 as well, and it can do all the buzzwords he mentioned.

Nothing wrong with being an amateur.

There is something wrong with dissing "buzzwords" you don't understand.

When you have something useful to say and a better attitude, then dialogue maybe possible. But until then, have a better day.

There is something wrong with answering someones request for learning resources with a bunch of gatekeeping.

You said Fusion is for amateurs, and that "real" MEs don't use it. That's wrong, plenty of real MEs use it. You then listed a bunch of features that Fusion 360 actually has in a way suggesting it doesn't.

You also used a bunch of terms and pointed towards the importance of knowing those terms - which is just another form of gatekeeping. You didn't mention them in a way that suggested them as useful search terms to research.

And now you are saying I don't understand your buzzwords. Well, I do. Now what?

My attitude is simple: provide op with something that helps and encourages him. Telling him his tool is amateurish and throwing around some ME terms doesn't achieve that.

I think focusing on what cad tool to use is a bit like fussing over what brand of pencils to use as a professional artist. It really doesn't matter if you start with fusion360, Catia, inventor, AutoCAD, SolidWorks because these tools are all trying to keep the amount of surprise for people switching to a minimum. You will likely get to use whatever your employer has licensed and if you work in 2 places, chances are you will have to learn 2 tools.

I started with pen and paper and had to do the 3d part in my head, and working out the material resistance calculations with equations, no fancy finite elements...for context.

Just to add Creo and Siemens NX to your list of major CAD softwares.

There is a russian one also, but I don't know the status. Or if it is only a kernel like opencascade.

One of my favorite CAD systems to use has been one called IronCAD, but it's not huge in terms of market share.

Not OP but isn’t your definition of gatekeeping in all industries and it is wrong to point out industry expectations (of course delivery matters)? Like if a kid learns programming using Scratch, you’re not gonna be like NO! Real programmers use C++! But if at one point the kid wants to take programming serious enough, you should explain to them that the industry expect certain tools and skill set.

I would argue CAD/CAM packages are the same. While there’s absolutely nothing wrong with fusion360 (I use it to for persona use too), it is true how the market penetration is extremely slim. Even the industrial sibling Inventor has only a small percentage of the market. While a lot of it is historical reasons, there are good reasons why most small to medium sized companies use Inventor/Solidworks and MasterCAM as their main driver.

I’ve learned most of my design/build knowledge out of necessity. Eg, I need a granite base, well how do you do that..

Without knowing the specifics of your part. Usually you can trade a more expensive process and still get a workable prototype part if you want to avoid molding. Eg, commercial 3d printing, (assemble panels together for larger parts), cnc milling.

Do you have a validated market for your product? If you don’t want to do the equipment purchase upfront but can demonstrate that your are a competent client, a contract manufacturer would be able to help you with the smaller first runs.

There seems to be very little machinery available for making small volume injection mold runs of your own. The industry has gone in the direction of large, expensive machines that can crank out lots of one design quickly, and then switch tooling to do the next guy's designs. This makes sense for contract manufacturing, but not for molding your own parts.

That said, contract manufacturers are easy to work with. They'll do the mold design based on your CAD model of the object. Making the molds is the most expensive part.

The nature of injection molding is such that pressures go proportional with part fill volume. If you do anything larger than bottle caps or radio knobs you'll need a large, powerful machine - no way around that.

I was in similar situation. However no metal processing. I found out, that PA12 nylon sintering would be a great alternative for injection moulding in small quantities. Buying used equipment is always pita. It often breaks and some special parts are only available from manufacturer for big money. I see this in relative’s sawmill as well as in machine park of friendly electronic manufacturer.

I'm a product design engineer, I have been designing mass produced products for over a decade. Happy to help if I can.

How big are the parts you want to make, and how many different parts are there? If you could send a link to pictures or parts on the open market you think are similar, it would be helpful to get an idea of type of thing you want to make.

I started this course a long time ago and never finished, but it's pretty good: https://ocw.mit.edu/courses/media-arts-and-sciences/mas-863-...

> How can I move to this "next level" of prototyping and small scale manufacture?

Maybe opening a small lab for youngsters, schools and happy triggers in your neighborood? You would personally benefit from new, like-minded acquaintances while keeping your running costs covered and surveying business opportunities.

On the electronics side of things, I recommend "The Hardware Hacker" by bunnie.

Traditionally this is under the umbrella of engineering, typically mechanical engineering (in Aus. at least). That should give you a more concrete starting point for resources.

So, you asked this question 18 hours ago and haven't bothered to comment once. Do you actually care or just want to waste everyone's time?

I don't know about the OP, but this thread is fascinating in general.

It's been a while since I worked for places that made physical objects, but injection molding was always something you subbed out.

You can upload your designs in STL format to a number of injection moulding services for quotes.

It is possible to get into injection molding for well under $15K, but it is highly dependent on the volume and dimensions of the item you want to make, and the quantities. And your skill.

Injection molding machines get big and expensive quickly. But there are some hobby / education molding machines that are relatively inexpensive. They'll be limited in the part size, of course, but it will be very educational. You can find used industrial machines, but ones in a just-right size are harder to find.

You can make molds using high-temperature epoxy (hundreds of shots), high-temp SLA resin (presumably at least tens to hundreds), aluminum (thousands), or steel (often refurbished for very long lives). Having a CNC mill will be very helpful--something like a Tormach 440 is $7K or so new, and is useful for all kinds of things besides mold making. Depending on the complexity of the part and the finish you need, this is probably intermediate machining skill.

Machines are often rated in clamping force (e.g, "15-ton"), but shot size/volume (usually expressed as the weight per shot in polystyrene) and injection pressure are also important. Horizontal machines can take up a lot of space, but can use gravity to clear the part after it's made.

For smaller parts, Morgan makes some nice benchtop machines, but they're pricey. If I was going to buy a new machine, I might look at this cute little horizontal: www.robotdigg.com/product/657/ It's about $9K I think.

For me, it made all the sense in the world to buy an old import vertical 15-ton machine ($2,800 on eBay) and design and make my own aluminum molds for a product I sell. I learned a lot, and now can make other parts. I spent less than the cost of having a mold company make me a single mold (I think the quotes I had were $3,500 or so for my relatively simple, small part). But I have access and experience on a CNC mill, lathe, etc. If you don't have that, or don't live near a makerspace, then you'd need to factor in the machining equipment and tools.

I currently produce an ABS case for my product, actually resembles a DB-25 shell. About 2.5 x 1.5 x .8". I did use Fusion 360 CAD and CAM, and a Tormach CNC mill. Used aluminum for the two mold halves and spacers, actual ejector pins (they're inexpensive) for the ejectors. About a 40-second cycle time. It took quite a while to get everything put together (the manual is in Chinese, and actually is for a similar but not identical machine), and I'll probably add on some microprocessor control soon to make it a bit easier to run. It is extremely pleasing to be able to sit down and fill up a box with custom plastic parts. Need to add a logo or product name to the part? Throw it on the CNC mill and you're set.

How much would I pay to take a course to learn how to create molds and set up and run an injection molding machine? Right now I've spent less than I would having an outside company make just the molds. Your outlook may be different, but learning and creating actual products (subject to some size limitations) is very possible. It all depends on what value you place on learning new skills, versus the raw economics of it.

The booklet from Morgan called "Cutting costs in short-run plastics injection molding" covers simple mold making, and the case for using high-temperature epoxy for short-run molds.

The NYC CNC folks machined their own mold from a pre-built mold blank on their CNC machine, then had a company do the injection molding.

(I'm omitting the weeks I spent stripping and rebuilding a small pneumatic machine--it was just too small for my part. Another learning.)

By the way, I had a toy injection molding machine as a kid. Small but completely functional--came with a mold for a toy soldier, I think. I'd cut up sprues from plastic models. Probably burned my fingers more than once, but an excellent experience for a kid. Wish that was more common.

The problem is that you will spend more time tweaking machines than getting any work done.

Has to be a really good balance when it comes to machine quality and capabilities.

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