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Guerrilla guide to CNC machining, mold making, and resin casting (2015)

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51–60 of 162 posts

Re: Guerrilla guide to CNC machining, mold making, and resin casting (2015)

#51

As somebody trying to get into mechanical engineering while living in a small urban apartment, this has been an incredible resource... not that I've made much progress along the lines it describes though. It's tough to plan a path toward growth in these skills without sustaining inordinate expenses at each step. I can't afford to become afflicted with Gear Acquisition Syndrome. I've come close to dropping huge sums o…

Hey man, actual Mech-E here. Also general mechanical hobbyist and handyman; not just one of those CAD guys

Just some quick things that may help you point you in the right direction. This is coming the "small scale hobbyist", not indusdrual profesional viewpoint:

-getting better and making actual projects come to fruition is actually a lot like CS. A lot. Somebody can spend all their time reading CS theory, textbooks, MITOWC, whatever. Their technical foundation will be strong, but will struggle when it comes to coding syntax and spesific program/firmware issues. Some get stuck in that mode and are paralyzed to take action

I'd honestly recommend dropping the mech-E textbooks to read just for reading's sake. It will fill you with generic knowledge but not a better builder. Instead I'd be thinking about "what do I want to build"? Kitchen knives? Custom pens? Automotive mods? It does not need to be something you make forever. Just something that seems fun now (just like the pet CS video game project)

Just like CS hacking (in the PG sense), THEN you will start to look up how it's done. Kitchen knives need metal forging? Okay, now its time to look up edu material for that. What tools are needed? Can I custom-make tools to get them cheaper? What edu material is out there for that… rinse and repeat

...just remember 2 things. 1, safety first. 2, a pretty drawing means nothing if you can't manufacture it to your desired specs

-honestly, drafting or 3D modelling, it's all fine. What's important is what allows you to implement your ideas and record them fastest. Also, right tools for the right job

I made a bench for my balcony. Just rough, imprecise measurements, knowing I'd make ad-hoc cuts to size when I had my material

For extreme lightweighted, funtion-over-form stuff or geometrically sensitive stuff, ya, CAD or FEA software will be needed

Just use whatever is appropriate and will allow you to achieve the results you want. Honestly, if you're not making F1 parts, drafting or CAD is fine

-your proto-prototyping is GREAT. This is exactly how you get started into this. Try something out on a small scale, see where you could improve with tooling, materials, methods and process, try again. Want to make a bronze casting? Try plaster casting first. You say you're lost, but you are ahead of 99% of people in all the damn makerspaces or home hobbyists. Trust me :)

-janky tools. Beautiful. For things that don't need to hit specifications (like firm +/- tolerances), this is one of my favourite things to do. I made an air extraction unit with a thrift shop electric leaf blower motor and some scrap hvac conduit. This is a crucially important skill IMO, as mechanical things get expensive. This allows you to go MUCH further with the money invested to try things out

-collecting weird stuff? Get some plastic bins. Lol. Out of sight out of mind

And last tip? When things around you break, try to fix them. That really starts to add to your "mechanical intuition". I'm pretty familiar with hvac, plumbing, general indusdrial fastners, air and fluid power systems. Next time your sink clogs up, don't call the plumber right off the bat. Explore tutorial videos to see if you would be comfortable doing it (and no problem of you're not; i am not with electronics). But at least you start to get very familiar with standard tools, parts, designs, etc. It's almost uncanny how similar many product classes are

Re: Guerrilla guide to CNC machining, mold making, and resin casting (2015)

#52

Earlier quoted context omitted.

Mass market junk is cheaper to make in China and ship by the containerload than it ever will be to produce locally no matter what method you use to manufacture them. Personally I wished people would stop buying these things whose only real goal seems to be to end up in landfills.

I mean, what do you think most people are using 3D printers to make?

Sorry? What I think isn't really relevant. What I see is relevant and what I see is a lot of people making prototype hardware and small series stuff that would be very costly (sometimes impossible) to produce using any other method.

It all depends on where you are looking. You claim - fairly categorically - that 'the "makerspace" has seemingly failed to produce any sort of meaningful Renaissance in small-scale US manufacturing' but that is a complete strawman, it only works if you assume that a renaissance in smallscale US manufacturing was the original goal and that never was the case.

Makerspaces are not even a requirement to be part of the maker scene. Over the past couple of years I've seen elements of it all over industry and in series production up to several 100 units (probably a few in excess of that) of parts that you would have a pretty hard time making otherwise and with such low start-up costs. That you have an entirely different bar for success isn't an issue with the maker scene.

I don't doubt that there are people that end up making things they throw away. But if you're building custom machinery the tools from the 'makerscene' have long escaped the hobby lab and are now a mainstay in any prototyping shop. Tooling, jigs, parts, gears(!), brackets of all shapes and sizes, adapters, custom plugs, cases, scientific gear for lab setups and so on. The list of items I've seen produced with these tools is longer than I care to list here.

Re: Guerrilla guide to CNC machining, mold making, and resin casting (2015)

#53

Semi-related: As an average consumer I'm disappointed that nearly a decade of the "makerspace" has seemingly failed to produce any sort of meaningful Renaissance in small-scale US manufacturing. I've purchased the odd 3D printed or resin cast tchotchke from small operations a few times at this point. But it's still disappointing that if you need professional quality products, you still either need to pay out the nose…

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Re: Guerrilla guide to CNC machining, mold making, and resin casting (2015)

#54
post #47

Earlier quoted context omitted.

I am specifically thinking of a Christmas bazaar I was just at. You had all of these booths selling beautiful customized phone-cases and earrings and candle-holders and etc. And nearly all of them are starting with Chinese made plastics and putting labor intensive value on top of it. And there was a single 3d print shop booth that sold glorified paperweights. It just seemed to me that there is clearly a market failur…

I used my 3D printer and CNC to assist in making these: https://www.longtailwoodcraft.com/gallery.html There's no 3D components in the cutting boards or wall art itself. I make jigs and spacers and all sorts of things to assist in assembly and manufacture. An FDM 3D printer is useful for much more than making glorified paperweights. There's immense value in being able to make any jig you can think of, very precisely,…

Sure. I am trying to limit my comments to the value of 3D printers in the consumer space since I know they are not without their applications.

Re: Guerrilla guide to CNC machining, mold making, and resin casting (2015)

#55

Semi-related: As an average consumer I'm disappointed that nearly a decade of the "makerspace" has seemingly failed to produce any sort of meaningful Renaissance in small-scale US manufacturing. I've purchased the odd 3D printed or resin cast tchotchke from small operations a few times at this point. But it's still disappointing that if you need professional quality products, you still either need to pay out the nose…

>I'm disappointed that nearly a decade of the "makerspace" has seemingly failed to produce any sort of meaningful Renaissance in small-scale US manufacturing.

In my opinion, this is one aspect of the modern "rise of the novice". By this I mean, people acquiring just enough knowledge of tools and techniques to make cool-looking stuff, but not enough to make meaningful or useful advances.

Re: Guerrilla guide to CNC machining, mold making, and resin casting (2015)

#56

I skipped right to the section on CNC machining because that's what I have some expertise in. A couple pieces of feedback: - In section 2.1.1 there is a note that states "CAM applications are designed to fail safely; that is, if any of the features of the model cannot be reached without plowing through another essential section of the geometry, the problematic region simply won't be machined at all." This is really,…

>https://www.r-c-y.net/posts/machining/

Great info, thanks for posting!

Re: Guerrilla guide to CNC machining, mold making, and resin casting (2015)

#57

Earlier quoted context omitted.

I'm saying that if you've been kicked out of Fusion 360 or it no longer exists, you won't have anything to open the file with. As opposed to locally installed software which will run indefinitely.

Most professional cad software is behind a subscription or license server, so I’m not sure what the alternative would be.

There’s not as many offline perpetual license options today, but that model used to be common.

Re: Guerrilla guide to CNC machining, mold making, and resin casting (2015)

#58
post #19

Semi-related: As an average consumer I'm disappointed that nearly a decade of the "makerspace" has seemingly failed to produce any sort of meaningful Renaissance in small-scale US manufacturing. I've purchased the odd 3D printed or resin cast tchotchke from small operations a few times at this point. But it's still disappointing that if you need professional quality products, you still either need to pay out the nose…

Another problem is that really good CAD software is expensive. I have used FreeCAD. Its instability frustrated me. Not very rewarding to work on a part that needs a moderately complex feature like a loft, only to find out that after adding the loft FC crashes every few minutes so the part is essentially impossible to edit further. SolveSpace is much more stable but it doesn't have those complex features at all. You c…

For FreeCAD, I recommend trying RealThunder's dev branch, which fixes its main topology issues. (They're working on merging but it's a big review). https://github.com/realthunder/FreeCAD/releases

But setting that aside, rather than a philanthropic billionaire, I've long thought big companies like Ford / Boeing / Mitsubishi ought to pool together into some kind of consortium and buy out Dassault to open-source the code. It would probably pay back multiple times over for them -- not through saving on licensing fees, but through all the little efficiency improvements throughout their supply chains. Small machine shops would be able to offer more competitive quotes to customers; more shops would pop up; lead times would improve; file formats would standardize and version mismatches would disappear; new and custom features could get added faster Blender-like; independent developers could write plugins to automate or accelerate mechanical design; new ME hires could gain experience with the tools at home. It would be a huge boon to the industry as a whole. Shame that it hasn't happened yet.

Re: Guerrilla guide to CNC machining, mold making, and resin casting (2015)

#59
post #15

Earlier quoted context omitted.

Would you mind expounding upon this comment? Against what goal did it fail to deliver? I think I was more hopeful a decade ago than I am now that we'd see more decentralized manufacturing and more home-grown innovation, but I'm not sure that these were ever realistic expectations.

I think to OPs comment, tinkers at the turn of the century were able to turn curious scientific discoveries into huge consumer product segments. Radio, film, automobiles, etc all basically grew out of hobbyists at home. It seems like makers in general focus too much on self-reliance and making personalized goodies than actual creation.

I don't want to sell cars or radios. I want to make the things I need for myself.

Re: Guerrilla guide to CNC machining, mold making, and resin casting (2015)

#60
post #15

Earlier quoted context omitted.

Would you mind expounding upon this comment? Against what goal did it fail to deliver? I think I was more hopeful a decade ago than I am now that we'd see more decentralized manufacturing and more home-grown innovation, but I'm not sure that these were ever realistic expectations.

I think to OPs comment, tinkers at the turn of the century were able to turn curious scientific discoveries into huge consumer product segments. Radio, film, automobiles, etc all basically grew out of hobbyists at home. It seems like makers in general focus too much on self-reliance and making personalized goodies than actual creation.

I think the problem comparing to the last turn of the century is the cost of real innovation is much higher (ignoring that most “hobbyists” in that time period were quite affluent). A key difference would be that many foundational technologies were ripe for discovery then, but we are now in the optimization phase.
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