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

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

#121

Post by kragen »

s1artibartfast wrote: post #116
kragen wrote: post #115

Earlier quoted context omitted.

I mean, you meant "Kraige" rather than "Kriage", right? I wasn't deprecating the book.

Ah yes, it was hard for me to tell the difference even reading the spellings side by side. That said, it is definitely the weakest of the suggestions. The rest are serious books that a professional might refer back to. On the other hand you should really never need to refer back to a statics text, and it could be switched out for any number of options.

I really appreciate the recommendations. I have enough knowledge of the field to understand that control engineering and vibrational modes are extremely important but not enough to know what's most important to know about them or which books are more reliable or better written.

What do you think about Reuleaux's Kinematics of Machinery and the Machinery's Handbook?

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

#122

Post by toss1 »

dragontamer wrote: post #4

Notes vs 3d printers. 1. This guide is about making the mold-of-the-mold, the mold, and finally the final product. Its at least 3 steps before you get the final piece of plastic, rather than a single step process like 3d printing. 2. I hear that expensive software can help automate this process ("Design Product" -> "Auto build mold" -> "Auto build mold-of-mold"), but software is surprisingly expensive for hobbyists.…

>> you wanna design your mold to "cleanly lift" off a piece without anything getting stuck.

THIS!!

Make sure you have a good draft angle and reliable release agent coating, or a multi-part mold that can come apart at the seams (which does 99.9% mean a flash cleanup step in your mfg process)

With those, it will work great. Overlook it, and you'll have a very tedius cleanup job before your next part, or worst case, an expensive doorstop or coffee table piece.

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

#123

Post by acyou »

DalekBaldwin wrote: post #33

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…

There's a 18 part video series by Dan Gelbart I can recommend where he goes over how to prototype products using a laser cutter and a hydraulic press. If I was setting up a home shop, I'd start there. I have very good access to CNC milling and turning machines, but usually find it cost and time prohibitive to go that route, preferring to laser cut/3D print wherever possible. https://www.google.com/url?sa=t&source=web&rct=j&url=https:/...

Urban apartment, I'd stick to electronics, pcb, soldering, code.

You want meche career change, just go work in a local cnc machine shop that runs Fusion 360. Then you can have unlimited access to all the tools you could ever want. If you want to be a good designer, I'll sell you my book once it's written.

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

#124

Post by johnwalkr »

rspeele wrote: post #19
legitster wrote: post #6

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…

Solid modelling software is very hard to build, and FreeCAD, SolveSpace and OpenSCAD feel like they are built by hobbyists who had heard of CAD but not actually used it talked to anyone who had.

Solidworks for makers was kind of hard to find but free until recently. Now it's $99 per year. Of course, you can't use it for commercial work past a certain point. It kind of seems like it's dying as well, they are going all in on cloud but their cloud product is terrible.

I'm a Mech E (well, originally anyway), do hobby stuff and sometimes I do side jobs. I now use and recommend Solid Edge even though it's not as nice to use as Solidworks. It's free for hobby use, and something like $90/month when you want to use it commercially. You can pay for the license one month at a time.

Solidworks is about $4000 to buy and then $2000 to maintain the license. You can keep using the version you bought, but eventually you have to upgrade in order to work on files with someone else, or to fix a breaking bug, like when 1-2 year old versions were unusable with HiDPI displays. Previous versions get no updates, period. When this happens and you need to upgrade, you have to backpay all of maintenance license fees you didn't pay, or start over again with a new $4000 license.

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

#125

Post by naasking »

gaze wrote: post #114
naasking wrote: post #88

Earlier quoted context omitted.

Lots of open source designs that can route steel, like PrintNC [1] and OpenBuilds [2]. If all you need is Aluminium, then you can make do with something like the RS-CNC32 [3] or MultiBot [4]. [1] https://wiki.printnc.info/en/about [2] https://openbuilds.com/builds/category-list [3] https://www.makerfr.com/en/cnc/rs-cnc32/ [4] https://hackaday.io/project/176110-multibot-cnc-v2

They don’t hold great tolerances, but if that’s ok then they’re fine.

What do you consider a great tolerance?

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

#127

Post by at_a_remove »

Once again the brief period of excitement I had shortly before the closure of TechShop is roused. They very foolishly offered me three months free, and all of the classes I could take during that time, free! I did every class but the CNC embroidery. Completely hog wild.

In my defense, I was primed for it: extensive drafting courses, some engineering courses, the ability to do math with a parametric mindset, woodworking in high school, some focus on material when I was still on an engineering path before switching to physics, and so on. I just lit up and ran about the place like a crazed monkey churning out personalized knickknacks for friends, throwing together little projects, doing a spot of weird art.

All of the spaces are now faaaar away and I miss just banging out strange things on a whim.

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

#128

Post by donkeyofd00m »

digdugdirk wrote: post #108
donkeyofd00m wrote: post #51

Earlier quoted context omitted.

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,…

This. 1000x this. Also, to add on to the reading comment - keep an eye out for old (40's->70's in particular) technical books and manuals on topics that interest you. I find they had a way of conveying information that was somewhat lost once video became commonplace.

There is a book I recommend to alot. Mostly out of intrest/leisure

60 years with man and machine

A guy who started as a millwright in 1890. Was a touring magazine editor until the end of ww2

It's hard to find but it's a banger

For spesific methods (like jewelry making), there are pockets of web 2.0 vbullitin sites out there... kind of like hacker news

That jewelry site in question (i used it for metal casting knowledge)

https://www.ganoksin.com/

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

#129

Post by DalekBaldwin »

krschultz wrote: post #82
DalekBaldwin wrote: post #33

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…

A question to answer: is the enjoyment coming from actually being the machinist, or is it coming from assembling something you designed? The answer could be either. But if you just want to bring something you designed to physical fruition and you are limited on space then I would recommend finding machine shops that will make what you design for you. This is what Protolabs, Shapeways, Xometry, etc do. You don't need…

The goal is the end product, yes. But there's joy to be had in getting there. And more importantly, I know I won't be able to achieve it without a good feedback loop for iterating on my designs, which means doing at least some machining on my own.

For one thing, sketching out variations on a design typically reveals there's a wide space of possible parameters in the spec. In many cases it's obvious that only a small subset will actually be technically feasible (either for machining or for reasonable functionality of the finished artifact or both), but not obvious exactly what that subset will be.

I'm not even talking about what could be revealed by finite element analysis or other formal methods (though I'm not averse to learning those too). I mean the feel, the taste, and the intuition I can't get from just drawing and doing the math. Like Jackie Stewart said, "You don't have to be an engineer to be be a racing driver, but you do have to have Mechanical Sympathy." I have mechanical sympathy for computing systems, for rapidly narrowing down appropriate design spaces in software projects, but I don't yet have mechanical sympathy for mechanical systems.

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

#130

Post by donkeyofd00m »

Prcmaker wrote: post #109
donkeyofd00m wrote: post #95

Earlier quoted context omitted.

Lol sweet... so even you guys with highly dangerous stuff too Hey, my favourite jank tip: an O ring blew but you don't have a replacement? Bubble gum works pretty well for a few days

If it gets it through the test, it did its job. Ratchet straps can be a good insulator, when clean and used properly, to higher voltages than you'd suspect.

Sometimes I wish there was an archive of all the small tips like these

But other days I kind of like the piecemealed nature of sharing "tribal knowledge" when you bump shoulders with others

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