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Anyone know anything about CNC machines (bonus points for 3d printer knowledge too)...

I want to buy a metal-capable CNC as well as a 3D printer to supplement it. Mostly to do random projects. But could use advice on what to purchase.

I am also curious about the software side, ideally id like to get a CNC that is easy to work with from a software level and bonus points if i could somehow use the same software to design for both CNC and 3d printer since parts for any particular project are likely to come from both.

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@freemo making the models is probably going to be the same CAD/STL software, but finishing them isn't. you need a slicer for the 3d printer, and god knows what for the CNC (path tracers/calculators i think, and there are some simulators.)

@meowski does the CNC thing.

@icedquinn

Thanks, yea thats kinda what i figured on the 3d side.. though im not clear how you go from a CAD design to the slicer. Presumable a cad design consists of multiple parts in one design fitted together. The 3d printer, as well as the CNC (depending on which part) will handle the parts indivudally.

So I presume there is some way in the CAD program to break up your design into files where each file represents a different part in a single design. Then you send the 3d ones off tp the slicer, then the CNC ones off to whatever handles that.

Also, like you, I am less clear on the CNC side than the 3d side (though im not all **that** clear on the 3d side either except at a high level, where you seem to have worked with it more).

@meowski

@freemo @icedquinn i use autodesk inventor for modeling, mastercam for generating toolpaths, and uccnc software to control the machine

@freemo Your CAD software will treat each manifold object as a "body" (terminology varies) and you export each body to a mesh in STL/OBJ format for your slicer to process. Slicer gives you gcode for the printer.

@PCOWandre ahh ok that makes sense. So the cad software at least has some sense of discrete parts and can break it down when it comes time to manufacture it...

Now the only question is, what printer and CNC do I buy that is both metal capable and feature rich from a software compatability standpoint (I'd imagine some CNC or 3d printers night not work on open standards or something that i need to look otu for).

@freemo @PCOWandre i used a Prusa. as long as you stick to the reprap side of the fence you can pretty much do anything you want.

@icedquinn Ahh just checked, Prusa is the slicer, not the design software... ok still useful but I assume all slicers work ont he same file formats so I think picking the design software might be the more critical decision here, correct me if im wrong.

@icedquinn ahh ok, i was looking at the software by the same name. cool. I think for a 3d printer im going to need high-resolution and dual filament as minimum requirements... I will likely need a pretty generous size as ill probably be printing relatively large objects.

@icedquinn To clarify I know that on the 3d printer I'm looking for a bare minimum of 0.1mm resolution or better. I know that rules out most printers that are less expensive,especially when you couple it with my need for a relativly large printing volume.

@freemo Also, I can't speak to choosing CNC hardware, but three quick printer reviews:

1. Ender3 -- requires patience. And mods.

2. Anycubic Chiron -- huge print area but can be annoying to level. Ultrabase build surface is great.

3. Artillery SX1 -- very nice quality out of the box, but the clone Ultrabase isn't as good as the real thing.

@freemo The Ender 3 issues/mods? The stock extruder was plastic and had slippage and wear problems; replaced. The stock BuildTak-type surface seemed to flip between failing to stick and holding with enough force to mandate a hammer to get things loose. Replaced with magnetic build surface. Stock firmware has thermal runaway protection disabled, which might have changed by now. Spool holder is stupid.

Ultimately, I got plenty of good prints out of it but the hassle was enough to move it on when I got the Chiron. The Chiron hit the reliability point where I don't stick around to watch it.

@PCOWandre ok so yea that sounds troubling and speaks to quiality issues... so might not want to go that route then thanks.

@freemo I'd strongly advise everyone considering their first 3D printer purchase to remember one thing: the cheap 3D printers from China are exactly what you'd expect from cheap Chinese products.

They're certainly capable of doing the job, but they're a hobby, not a commercial tool. These machines require one to make a hobby of 3D printing, not just use it as a simple tool towards a greater whole.

You will fight with levelling issues and speeds/feeds for new filaments and bed adhesion and alignment and banding and vibration and all sorts of fun things. On the plus side, there's usually a fair few useful mods on thingiverse that you can just print to work around issues.

Tip number two is a lot of the community for these printers is gated away in members-only Facebook groups which is a pain in the arse.

@PCOWandre I already knew going in that the cheap stuff wasnt an option, particularly given my high resolution requirements. Precision machining is never going to be cheap.

@freemo Depending on where you are, it might be more sensible to proof your CNC designs on your 3D printer and then send the CAD files to a job shop to get them machined.

@PCOWandre that would get too expensive over the long term, especially considering that there may be many design iterations. Plus the CNC is likely to also enable me to do PCB and other things.

If nothing else having my own CNC is going to greatly reduce turn around and thus reduce project development time significantly.

@freemo @meowski Slicers accept 3D model files. They analyze the model in layers, which the 3D printer works with, and then compute a path to move the tool head on that layer while extruding filament. So anything that produces a 3D model works.

A lot of people use Blender (or try to) for cosmetic 3D prints. I always tell people not to do this, although if you're using something like Sverchok then it's basically a CAD program at that point.

CAD software usually has a button to export to a format like STL or OBJ.

I would assume you import finished STLs in order to make use of finished parts from elsewhere in a build. But it probably depends on the software you use.

@icedquinn

I havent used blender in many years, but from what i know of it, specifically the work flow, it would seem more suited for 3d models and animations than for physical machining. Machined objects usually have a lot of symmetries and uniformity to their design since they are functional more than aesthetic. It just doesnt seem what blender is intended for. Blender feels more like working with clay making arbitrary shapes where CAD feels more like working with a straight edge and technical drawings...

It would be like doing a blueprint of a house in blender. Sure you could do it, but man that seems way more convoluted than doing it in CAD software.

@meowski

@icedquinn

Does Scerchok enable things like solids of revolution designs? One of the thing that was nice about fusion 360 is you could basically just create solids from 2d sketches by applying things like a solid of revolution to it. I presume for blender to be useful it would have to do the same, perhaps this plugin adds that?

@meowski

@freemo @meowski freecad extrudes 2d sketches (with support for constraints on the sketches.)

i would be surprised if sverchock didn't, since blender already has a screw modifier which does exactly this.
@freemo @meowski i don't really know what you are trying to build though.

i used freecad a couple years ago. i was able to reverse engineer some parts with calipers and then re-create the constraints, although i wasn't ever able to print it (the part was just too small; would had to have redesigned it for something a 3d printer can actually do.)

@icedquinn

I am not trying to build a single thing. Thats the problem. The projects ill need to build will change as quickly as the direction of the wind as I have diverse hobby and professional needs.

For example one thing i need to build is the framework for a cryogenic cooling system, which will mostly be done with the CNC cutting out metal struts and such. Another thing I'd like to build is a smart chess board and chess pieces, yet another is a peltier powered near-cryogenic liquid-cooler (basically a 3 or 4 level stacked peltier configuration)...

so yea, ill be building all sorts of things and thus need a pretty versatile setup.

@meowski

@freemo @meowski well.

freecad works the most like inventor. i think its meant to be aping features from it but i never used inventor or 360.

openscad is all code. pain in the ass a lot of the time, but if the shapes you need are algorithmic then it's pretty easy to just give it a formula for hex faces and then have it dump out a pile of screws or something.

haven't used sverchok. i should though.

@icedquinn

hmm openscad sounds interesting, but "all code" sounds restrictive. Would be nice to see some sort of cross where you define the shapes in code and coordinates, it renders it in a 3d image to see, and you could manipulate it with it hte mouse to tweak the coordinate values.

The nice part about all code would be that it would be git/merge friendly (huge plus), AND would make it way easier to dynamically change the design if you needed each print out to be slightly different. For example if i did an arduino case I might need to 4 different designs depending on how many stacked modules are on the arduino. So instead of designing 4 different cases that were similar and maintaining them all in parallel I could just design it once and have the height as a parameter.

So yea openscad or something similar in nature sounds appealing, but as you said also sounds tedious if you really have to do it **all** in code.

@meowski

@freemo @meowski yup, it's all code. there was a fun talk where someone used clojure to generate openscad code though, and that's how the Dactyl keyboard was made.

'tis why i said its really only worth it for things like screws. if its a heavily technical part like IC casings, bolts, brackets and the like, where the model is simple, but parametric, and probably needs a lot of variants, its great.

@icedquinn

As much as I love functional programming clojure, and even more so lisp, just make my skin crawl. If it used any other functional language I would jump on that in a heartbeat!

Most models I am likely to do will be geometrically simple. A lot of it will be enclosures. Its unlikely I will have too much need to do anything "artistic" where there is a lot of fine detail. The only reason i need high resolution of 0.1mm isnt for fine detail but rather for precision fitting of parts. though also ensuring surfaces are relatively smooth is part of that.

@meowski

@icedquinn

From what ive seen so far OpenSCAD right now is looking like my favorite...

@meowski

@freemo @meowski openscad doesn't do the lisp thing. he just used lisp to generate openscad code.

openscads... not an exceptionally powerful language, is why.

@icedquinn

Right, I got that.

openscad languages limitation might be an issue, and something that generates the openscad code does sound like the right solution. Though im not sure I'd want to roll my own.

From the look of it im not sure openscad format is a "language" at all. There doesnt seem to be conditional logic or any of the elements of a turing complete language. Looks more like a file format for defining shapes.. I'd put it in the same vein as something like the file format for SVGs.

@meowski

@icedquinn

might be worth looking at blender then.. I dunno blender just feels like a tool not intended for this purpose and any plugins that try to fix that wont be as good as picking a tool actually intended for engineering design.

@meowski

@freemo Fusion 360 will generate STLs for slicing as well as run CAM for CNC. It's also very easy to use (by comparison!) and has a free tier.

@PCOWandre I was looking at fusion 360 and played witht he free tier. It looked awesome and indeed seemed to be nice and easy to use.

My issue with choosing that is that anything i design will be open-source. The free-tier however is really just a long-lasting free trial of 1 year and they dont seem to offer a truely free (as in perpetually free tier). So while I could accept a non-open source product the lack of a perpetual free tier looks like a deal breaker to me.

I can afford to pay for it, but if im doing open-source i want to ensure the tools i use are free and accessible to others who wish to contribute. So this is the only reason I might have to rule out fusion 360 even though otherwise I'd agree its the top choice.

@freemo @PCOWandre i've used freecad when reverse engineering parts i had on hand. it works ok for what i did with it.

@freemo It isn't a one-year trial, it is a free tier. Yes, obviously they could take that away in the future. I've been using it for three years now.

I get the open source desire, but the tools just aren't there for my workflow. OpenSCAD is great, but for a lot of the stuff I design I really want to kick the idea around visually. FreeCAD might have been more appealing if using it didn't involve un-learning a lot of F360 behaviour. It also just felt dog-slow and didn't want to play ball with the spacemouse.

F360 will export in standard formats like STEP so you're not absolutely locked-in.

@PCOWandre

I am not seeing anything about a free tier here:

autodesk.com/products/fusion-3

If I can find the truely free tier you speak of I might be ok with it not being opensource.. All I know is when i looked i dont see it and the "free" tier I was able to get and currently have explicitly stated it was only granted for a year.

@freemo You renew your free access at the end of each year.

@PCOWandre Ahhh ok, well that makes more sense. If that is the case it **might** be acceptable... but its still hairy for me because if they change that policy at any time I could have a huge collection of projects that all of a sudden are inaccessible without paying a huge fee.

If this were desktop software that might not even be a big deal because if they stopped offering a free tier you could always just use an older version. But it is web based, and I suspect this is part of the reason. So if they pull the free tier at any point you either need to pay or instantly get locked out of everything you ever made (and the community too)... thats a big gamble, it is hard to predict where that will go in 5 years time for example.

@PCOWandre There is also the fact that the free tier requires the work to be non-commercial... So im not sure how that would play out if someonewanted to contribute to an open-source project and they were using that open-source project commercially to make a product they actually sell (like an open-source enclosure they use on a paid product).

@icedquinn

well that is actually really cool... might just convince me to try blender afterall.

@PCOWandre

@freemo If there was a free/open source, or even a commercial product that wasn't insanely expensive for hobbyist use I'd consider moving. But right now, the options aren't good.

I do tend to export beloved designs to keep a local copy. But I always assume that all "clowd" services will let me down at some point and prefer to self-host everything.

@freemo

You may want to reach out to a local hackerspace/makerspace. Obviously, membership and capabilities will very from space to space, but this type of thing is often in their wheelhouse.

wiki.hackerspaces.org/Utrecht

@ejg indeed, in fact in my notes/todo for this task (improving my workshop) using a makerspace is one of the points I have that I am considering.

One strong motivator for me to use a makerspace is simply that my labs and workspaces at the moment are all at my philly home but I spend more time away from philly than at philly.

So what I will likely wind up doing is buy a CNC and 3d printer for philly and then rely on maker spaces when im in the netherlands. There are some amazing ones with high end tech.

That said, sadly the makerspaces near and in philly that I've seen arent nearly as nice as the ones in and around Utrecht. So I will almost certainly still need to buy my own machines even if i wind up using a makerspace in the netherlands.

@freemo all I know about CNC machines is apparently I need to learn OpenCAD

@freemo

I've only worked with homebuilt (rather, cobbled-together-in-the-lab-by-grad-students) CNCs, so I can't recommend specific products, but I'll try to pose some questions that you should consider, and maybe in doing so your decision will become clearer.

You say it should be metal-capable. What metals and form factors are you worried about - cutting shapes from sheet steel, milling complex 3D forms from aluminium billet, safely handling something weird like titanium or magnesium?

What size working area do you need? Is that a desktop CNC machine? A freestanding one, maybe the size of an armoire? A full commercial VMC, about the size of a minivan?

Are you comfortable maintaining it yourself, or will you need a professional to keep everything aligned/lubricated/operating? Come to that, do you want to build your own instead of buying a premade one?

Regarding 3D printers, I have a Printrbot Simple, but unfortunately I can't recommend it unless you only want to make orthogonal surfaces - diagonals and curves are terrible. You might consider something modular like the Snapmaker 2.0, which has attachments that can be swapped out to make it a CNC machine, laser cutter, or 3D printer, but of course this will involve compromises that single-purpose designs don't have to worry about.

@khird Snapmaker 2,0 was on my list till I learned it cant do metals.

@freemo Depends strongly on what metal & form factor. Here's a guy using it on aluminium sheet. Obviously you're not going to be using it on iron ingots or whatever, though

youtube.com/watch?v=BVBIDVgf78

@khird I know that at a minimum I'd like to work with aluminum.. would be nice if it could be steel too.

@freemo A 3D printer is essentially a CNC mill without a cutting tool. I would recommend a RepRap. You can always use PLA and do metal casting in a similar manner as the lost wax casting process.

@freemo Hey Freemo! I did a lot of 3d printer modding to my current machine, and I’ve got a few suggestions.

  1. For brands, I’d check out Prusa(high quality, high pricetag) or Ender (medium quality, low pricetag). I personally have an Ender 5. It has a modded mainboard with trinamic drivers which make it completely silent. The Prusa board has said drivers, but costs nearly double (even though some parts are 3d printed), whereas my board upgrade was ~30-40 dollars and my machine is all aluminum/steel. I would suggest against a Reprap, the quality tends to be a bit of a crap-shoot. BTW this is all FDM printing, for a plug and play option with high quality, I’d suggest looking at resin printers. They are excellent, and prices have dropped comparable to FDM printers, but the resin process requires some extra equipment (UV lights for curing, a way to store/dispose of waste resin, etc.) But strength, and resolution on resin printers is unmatched by FDM.

  2. For CAD software, I use FreeCAD, especially for “engineering” parts. For decorations/sculpting, use blender. FreeCAD is decent at what it does, but if you’re willing to pay for nicer ones like Fusion360 etc. I’d likely suggest those (especially since there are loads of tutorials on them). I’m just cheap and won’t shell out for it. For 3D printer slicer software, I’d heavily suggest Cura (or the Prusa software if you get their hardware). For CNC tool-paths, it depends on which machine you buy typically.

  3. For metal CNC, especially if you want steel, you’ll need a serious upgrade, probably even a plasma cutter just for sheet metal. If you’re willing to stick with aluminum and other softer metals, you can try to build it yourself or order something instead. For the DIY route, I’d check out a plan on OpenBuilds,then source your parts from AliExpress/BangGood (or OpenBuilds, but their prices are high). If you just want to buy one, you can easily grab a cheapo off aliexpress/banggood/amazon, or you can go absolutely wild and buy an AVID machine for $5-10K, and throw in that dual plasma cutter head for fun like this.

I hope this was somewhat helpful :)

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