Why does CAM software feel very manual & labour intensive

CAD & CAM Tool Chain
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Hi all,
I’m a maker with a pretty well equipped shop and a wide range of interests. I’m mediocre at a lot of things, like 3d printing, C02 lasering, manual milling & lathe work, welding, woodworks, electronics, programming, molding/casting, designing etc. (not to brag; just for context). In combination I can create a bunch of neat stuff for my clients which makes me (and sometimes them) happy.

Recently I came across a broken CNC router which I refurbished for a friend - new motors, new controller + new wiring was necessary. After this I needed to test the machine, and for this I needed to learn about CAM software / path generation. This is a new area to me so I was happy as always to learn new things.

I have used a little Vcarve (software which the friend uses), but changed later to Fusion 360 for my tests as this was the software I used for my 3d printing endeavours.

I’m very surprised about the tens or hundreds of settings I need to adjust (or know about to leave them be) to get anything useful out of the software. All the possible passes that may or may not be the route i want to take. I compare this to the settings for my 3d printer or even my C02 laser.
My laser handles almost everything itself. It knows the max acceleration it can do, I just set speed & power. Of course, this is a simpler machine.
The 3d printer needs to know a little more - what is the machine like? what is the material? what is the nozzle diameter? What Support, infill type do you prefer? But then, my slicer creates & connects the needed paths automatically: Overhangs, support, infill, tool changes etc are joined to something useful automatically.

I am under the impression that there should be a workflow around that I missed. One that allows me to specify my tools I want to use for the CNC job, and the rest should be done by the CAM software. Only have a 8mm endmill? Your piece will not have much detail, 3 passes required, but here is the path for the most beautiful piece you can make with that single cutter. Have an additional .5mm ball end milling cuttter? it will take ages, but here you go, one tool change required.

Instead I am presented with a massive amount of options for passes - 2d pocket, facing, slot, tracing, ramping, morphing, drilling… - for each tool, path. So, so many options.
To get started, I “just” want to get the best result with the tools I have, and maybe a slider for how long it should take.

As a new user, I would be happy with sub optimal paths that take longer or are less optimized. The more experience I get the more in-depth I could go.

So I guess my questions are:
Why the difference in manual labour for path generation in 3d printing and CNC milling?
Do I misunderstand the CAM software workflow?
Is CAM software not yet ready made for hobbyists like me, like lightburn for my laser?
Would a simplified workflow just not work because every setup is vastly different?
Have I just not tried the right software?

I guess I’m spoiled with simple but useful software for other machines. This will all get easier - the more I get used to the workflow, the better I have set up my tool libraries etc.
Also i’m pretty sure some of you seasoned CNC path wizards will tell me: Git good. Learn it properly from scratch. Which is reasonable. CNC’ing isn’t lasering, it isn’t even 3d printing, its inherently more complex. I’m so happy to learn more, but unlike my previous new lands I tried to conquer, CNC path generation seems to start with a pretty deep+tenacious marsh, and I was wondering if there is a paved route already. Or at least some friends along the way :slight_smile:

cheers & thanks for your thoughts!

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Great question and I’m looking forward to hearing what others think but as my current time is short, I’ll start with this sounds like a problem with the tool you chose( Fusion 360 ) more than anything. Try something a bit more approachable like Kiri Moto( Kiri:Moto ). Still a few things to setup but I found it a great into to getting something on the CNC and learning a bit about what one workflow would/could look like.

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Thanks for your answer. Yes maybe theres just other software around - Kiri:Moto looks interesting and very clean, never heard.
I guess i’m not just on the lookout for a simpler program though - those are usually, by definition, a bit limiting. I like those hundreds of settings in fusion - but only as an option for more advanced stuff.

In my experience with other tools & softwares, as soon as i would master Kiri and would go on onto bigger and more complex setups, I would bump to the limitations of the software. Which would made me want to change to a more complex one. Where i would dearly miss the simplified interface for simple setups…
Lots of hypotheticals, but i hope you get the picture.

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you’re heading down the path to trying to understand User Interface(UI) design. One of the reasons why I like KDE for a desktop( after OS/2 Warp was discontinued ) was because of the consistency of the UI and the use of levels of detail which can expose basic, standard, expert levels of configuration, control and usage patterns.

Kiri Moto had alot of the settings exposed by the developer found some people were getting too confused by so many options so he too implemented a layered approach to the UI.

Also, CNC milling and routing are exponentially more complex than laser cutting/engraving for many reasons and after decades of CNC machining experience behind many CAM software developers it’s not been simplified because you literally can’t do it unless the only material being used by all users of the software is something like cheese. Materials vary widely, endmill cutting capabilities vary widely, wearing of the endmills vary widely and machine tolerances and stiffness vary widely. It’s not simple because it’s literally is not a simple process because there are so many variables in materials, machines and endmills. 3D printers were super tough when the density and thickness of the filament varied, when the hotend heat control was unstable, etc. Materials no produced are much more consistent, hotend heat and extruder control is far far better. It still be tricky but great strides have been put into reducing those variations so consistent results can be had over a wide range of object designs.

Lasers are even easier since they are only 2D for the most part and they start getting a little tricky when you start doing things like engraving and tile work like the Norton White Tile(NWT) method is used. Just no where near the variability we see in the CNC space.

But, if you do have consistency because you’ve controlled and eliminated many of the variations then you can setup the CAM software to spit out the same settings and your machine will run consistently as long as you also take into consideration of endmill wear and machine wear and do due diligence testing your base material for variations which will render those default settings useless.

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Very interesting. So the homogenisation/standardisation of the raw material, hot ends etc in 3d prints simplified the printing experience immensly. Whereas just the fact that I can choose my own material - from cheese to unobtanium - to be milled multiplies the options which means there can be no standard. That makes sense.
And I see if your business is very consistent with materials, tool libraries and all, you can standardise your workshop yourself. Unfortunately thats not me, I work with whatever I have, I’m a one-man-show, its hard to invest a lot of time upfront for this new tool opportunity while having to finish jobs.

Kiri Moto seems to be more than meets the eye on first glance. The UI tricked my in the best way to believe the software is simple. great!

I’m still wondering though.
If I set my tool correctly, set the stock, set feeds & speeds and my desired finish. Given those parameters, i’d love to think that there must be only one mathematical optimal way to create my thing from my stock. An algorithm that chooses a roughing pass, than a facing pass and then the 3d-parallel pass (or whatever necessary), with the options to tweak parameters…

Does Kiri do this?
Or, from your experience, is it just logically impossible for a software to do this?

Maybe I live in a fantasy land, or had recently spent too many hours programming, where there’s always a mathematically perfect solution.

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Kiri does a very good job and the developer, Stewart Allen is quite skilled and actively updating and talking with users about their needs. He eats his own dogfood as they say…

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This seems unlikely to me. Many much simpler large search space problems are NP-hard. And that’s where, in programming, there is not always a mathematically perfect solution.

I tend to prefer “drinks his own champagne” ":smiley:

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haha, I like it!

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I was a little eager with my statement about singular solutions to hard, or even simple problems.

My laser with Lightburn does decide in which order it cuts 100 holes that are spaced the same. It may be not the fastest solution, but its a solution, and seemingly its not the dumbest one. Walking salesman problem is simpler in 2d than 3d of course…

not gonna lie, i’d prefer champagne too over dogfood :smiley:

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As @dougl mentioned: Go for Kiri and start with simple parts. The “Rough” operation will take care of almost everything. :sunglasses:

FYI: I use F360 on a daily basis. But I do 9 out of 10 milling jobs with Kiri. :slight_smile:

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LightBurn has more options for deciding on how things are generated too. There are the Common and Advanced tabs of each layer definition of the Cuts / Layers section and then there are the Optimization Settings found in the Laser section.

Lots of ways to generate Gcode operations in most of these Gcode generators and like you, I prefer those with the most settings. But when starting off, I like when there can be basic defaults to let me slowly screw up or screw with things to start learning what bits do what things.

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I guess “letting me slowly screw up” is a very good way to describe the way I like to learn new things.

Well thank you all for your insights. I will have a closer look at Kiri, that sounds very promising.

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Pick one you get along with… I’ve had many people try to steer me to different cad programs but it doesn’t matter which you chose, you will probably have to enter the same information.

If you need to cut a pocket, the software has to know the parameters of the pocket to be able to generate the code to perform the operation…

If you don’t need/use the pocket operation, there shouldn’t be any need to supply any kind of entries to something not being used.

I run Ubuntu, so I’m limited to those that run under some form of Linux. I’ve use FreeCad for a long time. It’s parametric, if created properly, you can adjust where things are by changing a number and letting it recompute the objects.

I can export in svg format (my preference) to load into Lightburn or Cura for slicing it for a 3d printer. I designed my flow meter housing in FreeCad, printed the case on the 3d printer and cut out the acrylic top on the co2.

flow-meter-crop-0
flow-meter-crop-02348×1488 738 KB

Find one that does what you want and learn it, the more platforms it runs on the better.

All machining is based on material, tool, and it’s relation to speeds/feeds… Speeds for spindles and feeds being the surface speed of the material… A 3d printer, it also has a feed that applies to how fast it’s moving and how much extrusion is happening… A laser has it’s speed, which is actually the feed, but that leaves power equaling speed… Same game the proper speed and feed for the operation.

To do this properly or suggest the proper numbers, the software would have to know the tool bit details, such as diameter and the tooth count along with the type of metal you’re using in the process. You would be further limited, in that a smaller bit has a smaller chip load and therefore is usually required to run faster. A change in chip loading requires a change in the proper speed/feed rates.

There are calculators out there that do this …

Good luck

:smiley_cat:

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On the other side folks complain when the machine does everything (mostly) for them.

One of my cnc’s uses proprietary CAM. You just tell it what bit you want and depth of cut and that’s it. Everything is preprogrammed with the machine. It does what it does with no more control over anything. It is designed for grandma’s with no woodworking background. And over all its pretty good. Its slow but for a hobby woodworker that is okay.

I purchased another cnc to work with normal cnc format patterns and I am having a heck of a time to make myself learn it. Spindle speeds, zeroing, swapping out bits, setting up parameters in the software are a little overwhelming when you never had to think about them.

I always seem to default to my old cnc.

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I just completed a two year machining program where the second half was focused on CAM. Before that I was an avid 3D printer and cheapo CNC router user. The department head was around when CNC started showing up on factory floors and shared stories about that time.

So, with that context I think there are multiple aspects to why CAM tools are generally complex and reward study:

CNC was created by and for manufacturers where every additional minute spent cutting or finishing can be the difference between profit and loss. This is a huge pressure to squeeze every bit of performance out of machines. It’s a good investment to train a programmer (meaning a CAM sw user) for years and to give them a $30k per seat software suite to save a minute per part. Competitive performance, to date, has been complex and expensive to achieve.

CNC started decades ago. Through years of consolidation, a few big companies now capture most of the CAD/CAM business. Sadly, a lot of corporate procurement processes just compare feature lists so every new sw company has to copy every feature in order to land big contracts.

Privately owned CNC cutting hardware is still a rarity compared to most other shop tools like table saws. That’s quickly changing and new companies are trying to make sw for people without years of training but it’s early days.

Anyway, that’s my 2¢ but I’d love to read other points of view as history is a gnarly tree.

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“designed for grandmas” i think is sometimes a super helpful concept, as you say yourself.

Some people get salty when they learn that a skill they learned with blood, sweat & tears is now available to children. Some electronics grand master is angry at children who use arduinos for blinking a LED, even though you could do it with a NE555P chip or whatever. I guess times are changing in that regards, making stuff available to more people, and I like that so much. Even if that example is not a very great solution, it is a rabbit hole to more complex projects.

Thanks trevor for your 2 cents. It makes sense that CNC machines from “the olden times” heavily rely and also florish on all the minuscule performance boosts you get from experience and a highly dedicated workflow.
But thats exactly the workflow i do not miss, why i made this thread. Coming from a DIY world to CNCing, its not yet where 3d printers are, or electronics, or anything that is available to so many more people that they where a few decades ago. And that fills my heart with joy. CNC will be here as well I hope.

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I also have a fully outfitted shop, there isn’t a tool I do not own. Been doing DIY since I was a kid in my dad’s shop so I benefit from years of practice and mentorship.

I have a love-hate relationship with my automation toolset and the associated toolchains.

I was a long-time Sketchup user until they make the free version useless then I switched to Fusion 360.

All these tools have a learning curve that only gets better by frequently exercising the entire toolchain. Clearly, the toughest one is Fuson 360, followed by Eagle.

My problem is that I always seem to find it faster to make one-off projects without going through the automation toolchain. Unfortunately, avoiding modeling artificially reinforces the notion that manual design and fabrication are faster. This of course is never true if I need to make multiples of something. Just as with manual fabrication skills, practicing CAD skills improves its speed and value.

I still use graph paper, cardboard templates, and manual fabrication techniques. I find that the time required to build and test a CAD model, then do a test run on the machine takes substantially longer than a sketch and manual fabrication. That always seems easier than trying to figure out why Fusion won’t copy and paste as I think it should.

I think CAD complexity is mostly driven by unfamiliar; workflow, tooling, and vernacular. The interaction of material choices, tools, and work holding only makes it more complex. The reality is that these same choices are made when manually fabricating it’s just that they happen on the fly prompted by real-time physical feedback in a familiar setting. You can quickly tell when you are pushing a router through a piece of wood too fast or too slow.

That said CAD tools have a broad range of fabrication possibilities without having a gaggle of tools and fabrication skills. Also, In general, CAD tools can produce more accurate results.

For me, CAD is just another choice in the array of tools I have access to.

In many ways, CAD skills can substitute for the lack of manual fabrication skills. Getting up the learning curve is worth it provided I keep the return on the investment in perspective.

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If you want quick and easy for importing .dxf files and cutting 2.5 D parts, trays, bowls, and other simple projects try Estlcam. I design in Fusion 360 for most simple non 3D carves and some 3D stuff. But, I generate my cam in Estlcam. It is so much quicker and easier than Fusion 360’s CAM.

If I am doing 3D carving, inlays, or rotary work, I turn to Vectric Vcarve Desktop. It makes that process so quick and easy once you work out your process and have your endmill specs in the tool library. Estlcam can also do 3D carves but alot if mine are 2-sided and again, Vectric makes that easy.

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Other people have covered some of this, but the first thing I tried to do with my CNC was build a table of optimum build speeds. A nice, simple reference where I could enter the bit and the material and get the quickest result without breaking anything. It took a couple of days for me to come to the conclusion That I was trying to stick about seven independent variables into a two dimensional table (like who made the bit, how rigid is your machine, how hard is the specific medium — wood especially has variations within species — and so on.

Then there’s the question (to use the analogy of others) of whose grandma are we talking about? The one who wants it done quick, the one who wants to do minimal finishing after the part comes off the machine, etc.

Sometime in the not too distant future we might have a path generator that asks all these questions, shows renderings of finished parts, asks you which one you like best, and generates the path, but until then I think we’re stuck choosing a tool and doing the best we can with it (or contributing to FreeCAD’s Path Workbench to make it do what you want :wink:).

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It exists in a proprietary format/system. Not sure if it can be implemented for a generic cnc machines easily or if folks would want it.

In the system, everything is pre-programmed for specific bits and its own hardware and all the drop down menus are in simple words commands. For example draft, normal, best or optimal for carving quality.

On the downside: What that means is you are locked into the specific bits and hardware the system uses and you don’t have the opportunity to deal with path generation because the system does it all in the background. So there is no opportunity for optimizing speeds.

On the upside: You never have to deal with path generation because the system does it all in the background.

For a hobby machine speed is not the overriding factor but to be fair it is not a slow machine. It is just not a fast machine either.

With so many hardware and bit options out there I understand why the CAM software needs you to input all the parameters for it to build its cut paths but, for me at least, it is daunting coming from a system that does it all for you. Though I really do need to sit down and learn VCarve at some point.

As other folks have mentioned, cnc is just one tool in the shop. I personally do not use it for manufacturing. My use of it is to embellish for woodworking projects that I have made using my traditional (powered) woodworking tools.

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