I Revived 3-Axis CNC Mill G-Code Simulator | Hacker News Reader

I Revived 3-Axis CNC Mill G-Code Simulator

github.com

142 pointsharvie48 comments

Nice and Thanks! Was looking for something like this with minimal dependency.

By the way, changing options updates browser history every time. You may want a debounce. Also, you could remove jQuery and make it even more leaner.

PRs welcome :-)

More importantly, what do you use for toolpath generation? I haven't found anything open source that really works...

In general, FreedCAD has 3-axis tool path support, and I've met the kind local guy who started the original Path toolbox.

For 2.5D there are several engraver options with the inkscape mightyscape plugins (scorchworks etc.)

YMMV with the island-routing and surface probing routines:

https://github.com/pcb2gcode/pcb2gcode.git

https://github.com/pcb2gcode/pcb2gcodeGUI.git

Also, we are currently evaluating: viaconstructor, inkcut, GCAM ( https://github.com/blinkenlight/GCAM.git )

If you want 3D contouring operations, than you could also try:

git://pycam.git.sourceforge.net/gitroot/pycam/pycam

And note, if you patch CAMotics to compile on ubuntu 24.04.x it still has a number of Qt5 GUI problems (not entirely unexpected with Qt impact on LTS programs.)

There are also direct gcode generator macros that support the LinuxCNC/emc language extensions. This is the most accurate methodology for turning and milling ops.

Best of luck, =3

FreeCAD. Or, if it's simple enough, I write it by hand and use Python to do loops. I've got a handful of Python scripts that can mill holes, make square pockets, write text in a vector font, etc.

Opensource options include:

- Solvespace --- limited to 2D last I checked

- FreeCAD has a workbench for CAM/toolpath generation

- BlenderCAM is a plug-in for Blender which is well-regarded, and together w/ CADsketcher/BlenderCAD works well for some folks

- Kiri:Moto

- pyCAM --- a venerable option, it worked well ages ago when I used my son's gaming computer to make toolpaths.

Rather rough (possibly outdated) list at: https://old.reddit.com/r/shapeoko/wiki/cam

Another might be gcad3d

https://www.gcad3d.org/

I've been long-term contributor to bCNC https://github.com/vlachoudis/bCNC/ But FreeCAD seems to be interresting choice lately as well...

Very cool.

It seemed to struggle a bit with a more complex example.

  N30 PAN=1 ST1="16MMRH" L=PCUA
  N40 Z=PRK
  N50 X1846.942 Y1157.433 G42 F=1.0 S20000 VF=1.0 AX=X,Y,Z PRF=-12.7 TP=1 L=PON M55
  N60 G1 X1832.8 Y1171.575 Z=-LPZ+-12.7 F=1.0
  N70 G1 X1832.8 Y1187.575 Z=-LPZ+12.2 F=1.0
  N80 G2 X1807.8 Y1218.8 I=1839.8 J=1218.8 F=1.0
  N90 G1 X1.2 Y1218.8 Z=-LPZ+12.2 F=5.0
  N100 G1 X1.2 Y757.2 Z=-LPZ+12.2 F=5.0
  N110 G1 X1807.8 Y757.2 Z=-LPZ+12.2 F=5.0
  N120 G1 X1807.8 Y1218.8 Z=-LPZ+12.2 F=5.0
  N130 G1 X1799.0 Y1218.8 Z=-LPZ+12.2 F=5.0
  N140 G2 X1767.775 Y1243.8 I=1799.0 J=1250.8 F=5.0
  N150 G1 X1767.775 Y1243.8 Z=-LPZ+-12.7 F=5.0
  N160 G1 G40 X1778.481 Y1260.693 Z=-LPZ+-12.7 F=5.0
  N170 G0 L=PSU
  N180 X1846.142 Y1156.633 G42 F=1.0 S20000 VF=1.0 PRF=-12.7 TP=1 L=PON M55
  N190 G1 X1832.0 Y1170.775 Z=-LPZ+-12.7 F=1.0
  N200 G1 X1832.0 Y1186.775 Z=-LPZ+12.2 F=1.0
  N210 G2 X1807.0 Y1218.0 I=1839.0 J=1218.0 F=1.0
  N220 G1 X2.0 Y1218.0 Z=-LPZ+12.2 F=5.0
  N230 G1 X2.0 Y758.0 Z=-LPZ+12.2 F=5.0
  N240 G1 X1807.0 Y758.0 Z=-LPZ+12.2 F=5.0
  N250 G1 X1807.0 Y1218.0 Z=-LPZ+12.2 F=5.0
  N260 G1 X1798.2 Y1218.0 Z=-LPZ+12.2 F=5.0
  N270 G2 X1766.975 Y1243.0 I=1798.2 J=1250.0 F=5.0
  N280 G1 X1766.975 Y1243.0 Z=-LPZ+-12.7 F=5.0
  N290 G1 G40 X1777.681 Y1259.893 Z=-LPZ+-12.7 F=5.0
  N300 G0 L=PSU
  N310 G0 L=POFF
  N320 PAN=1 ST1="FINTOOL" L=PCUA
  N330 X1817.607 Y747.3934 G42 F=3.0 S18000 VF=1.0 PRF=-12.7 TP=1 L=PON M55
  N340 G1 X1807.0 Y758.0 Z=-LPZ+-12.7 F=1.0
  N350 G1 X1807.0 Y758.0 Z=-LPZ+12.2 F=1.0
  N360 G1 X1807.0 Y1216.5 Z=-LPZ+12.2 F=3.0
  N370 G3 X1805.5 Y1218.0 I=1805.5 J=1216.5 F=3.0
  N380 G1 X3.5 Y1218.0 Z=-LPZ+12.2 F=3.0
  N390 G3 X2.0 Y1216.5 I=3.5 J=1216.5 F=3.0
  N400 G1 X2.0 Y758.0 Z=-LPZ+12.2 F=3.0
  N410 G1 X2.0 Y758.0 Z=-LPZ+-12.7 F=3.0
  N420 G1 G40 X-8.6066 Y747.3934 Z=-LPZ+-12.7 F=3.0
  N430 G0 L=PSU
  N440 G0 L=POFF
  N450 G0 Z=PRK

I do not believe that is standard iso gcode.

can you be more specific?

I am not sure how g-code parser in the simulator handles the line numbers... might be problematic...

https://nraynaud.github.io/webgcode/

I made one too, a long time ago.

https://nraynaud.github.io/webgcode/webapp/visucamTest.html

I did some code generation too, but it's bit rotting.

I have a post-processed NC file from Fusion 360...which I think is just gcode. How can I transform that into something this can simulate? My hacky attempts have failed.

Does Fusion 360 have postprocessor for GRBL? I've tried to make the simulator GRBL compatible. At least to some extent...

If that does not help, please share the g-code...

This is awesome. I learned CNC & manual G-Code on a Rockwell 3 axis in ~2000 and I am taken back tinkering with this.

The big problem for contemporary hobby CNC is that the G-code interpreters for small single board computers such as Grbl running on an Arduino are extremely memory-constrained:

https://bengler.no/grbl

which means:

- no loops

- no branching

- no variables

One work-around for that is:

https://github.com/NRSoft/GSharp

(I took a very different approach in my project linked elsethread)

I don't understand this comment- gcode never had loops, branching, or variables. And most folks use more capable controllers now based on ESP32 or whatever.

Update: I guess gcode does have loops, branching and variables: https://www.fictiv.com/articles/cnc-machining-macros-subprog...

Actually, in LinuxCNC dialect the gcode does have many features most machines will not understand.

This is why these machines can drill and helical-tap plates with thousands of holes with ease. Also, some folks will cut gear-profiles with a slitting saw, and 4th rotary axis...

https://www.youtube.com/watch?v=HI27vSoxCeo

Trying to pull these things off in a CAD/CAM package is usually a fools errand the old guys prank kids with... oh that sounds easy... lol =3

To be fair those features are pretty irrelevant these days. They really are a relict of times when gcode was handwritten. A skill i learned not even 10 years ago in high school.

cnc vendors are still bringing out new machines with new conversational g-code features though

really? got a link to that, im kinda curious.

i mostly see it on the 'titans of cnc' channel on youtube, but i don't have any of their videos on the topic bookmarked. take a look if you can stomach the shouty macho. in less arrogant alternatives, here's an abom79 video i have bookmarked: https://www.youtube.com/watch?v=-EyAWZuY7I4

I used to have some machines with Fanuc 6 controllers circa 1981 - 1983. They had variables, macros, branching, etc. I haven't been able to find what processors were in those old controllers, but I'm certain the single board computers of the last decade have more ram, more flash, and way more processing power. If GRBL can't do it, it is a software issue, not hardware.

Do you not consider Mach4/UCCNC/Masso/Centroid Acorn to be hobby? I’ve never encountered a hobby grade controller without loops.

They are the high-end/legacy-end of hobby CNC.

The Grbl/Arduino stuff seems most prevalent/commonly sold.

That said, I was remiss in not mentioning LinuxCNC, &c., and as you note, they do have a more traditional G-code implementation w/ loops and variables and branches.

But, I don't think that this simulator supports all of that --- could someone post a sample program which does that sort of thing and test it?

Yeah - I guess as a someone who considers my machining "non professional", I've never even really consider GRBL for a machine because "running G code" and "running a mill/router/lathe" feel like different categories. the lack of a reasonable GUI and access to the configurations and macros to handle things like tool changes etc. has never made me interested in GRBL. (I've only ever played with GRBL in the context of a router that needed to be run by UGS) and that felt so limited as to be useless.

That said, I'm on the brink of converting both my mill and router from UCCNC to Centroid just to be into some software that is more "machine operator aware" meaning that it offers more features targeting making my life easier as an operator, rather than simply running gcode in a machine-agnostic way.

which features are the ones that interest you?

G41,G68, S curve acceleration, and basic things for parking positions, pause, resume, single block, separate feed rate and rapid rate overrides, etc. Those would be pretty basic and important. Also, good gui driven probing routines, TLO calculators, and a sane tool library.

i see, thanks! i wouldn't have guessed those at all

Yeah, i think hobby CNCs should be going in similar direction the 3D printing does with klipper...

what if I want to learn CNC programming as a hobby, where one can go and learn and practice, without purchasing CNC equipment? (in NorCal/bay area)

lets say I want to emboss hello world on a piece of foam

One thing I'll suggest - if you ever want to cut anything metal, you'd probably do well to learn how machining works in general and by that I mean on a manual lathe and mill. The coding part is going to be easy for you (and probably anyone else reading this), but knowing what you want the thing to do is a MUCH different task than being able to tell the machine what to do.

Everything about how you move that tool through the work matters. Materials, workholding, spindle speeds, tooling, tooling coatings, feed rates, plunge speeds, all of these things need to be worked out and they all change when you swap a tool or a part etc. Speeds and feeds are dynamic, you need to learn about conventional-vs-climb milling, you'll need to know about cutter geometries and the materials the cutters are made of, when and how to deploy coolant, the list just never ends.

GCODE is, by far, the easy part for a programmer. It's a very simple language that hasn't changed much in the past several decades. "Knowing machining" is that tougher hill to climb.

My recommendation? Check your local community colleges/trade schools! I took a couple semesters of machining classes as a 40-something grown-ass dude and I learned a huge amount of stuff that would have been expensive or dangerous to learn by trying. You'll get hands-on access to big machines with someone over your shoulder helping to make sure you keep your limbs attached to your body.

Second this. My work occasionally deals with Gcode files. The coding is simple, knowing what to do (or not to do!) is harder. My first foray into the world of Gcode I named "Smokey" because it was a quick fix for another program generating bad Gcode that quite literally caused smoking on the work surface and could have lead to a fire had the operator not been paying attention.

And note that while Gcode is consistent it's meaning isn't always--is Z positive going into the work surface or going away from the work surface?

Z in a positive direction should always be up on a 3-axis machine --- the only time it might even appear not would be if the machine was already even higher than that position.

One would think so, but apparently it varies between manufacturers. Our machines are all carving up a flat surface resting on a table. I think what's going on is that functionally that means that the working head is permanently upside-down. Is Z measured in the context of the whole machine, or is Z measured in the context of the cutting assembly?

GCODE is not so easy in industry. Thanks to manufacturers having their own take on everything.

If you literally want to emboss hello world on a piece of foam, you can buy cheap CNC kits on Amazon like https://www.amazon.com/dp/B08HRLGL6C/ which will execute G-code.

They're weak and imprecise by the standards of CNC machines but if you're only looking to learn a bit and cut foam? That's a low price.

Search term for that is "makerspace"

Perhaps:

https://www.humanmade.org/

3x the price of Techshop. I miss TechShop.

Very cool project. what kind of post processors do you test with?

That's an excellent question.

Also, how are tool definitions to be handled? Each program seems to have their own approach, though some will place the tool description in comments. CutViewer is notable for doing this, and is the example I have been following in:

https://github.com/WillAdams/gcodepreview

(which is quite a different project)

EDIT: Note that the comment system which Cutviewer uses seems to be something of a de facto standard --- Carbide Create uses this same scheme.

I was thinking about implementing some tool management in that simulator... What system would you reccomend? I can't really find example of what cutviewer uses... Can you please send me link to sample definition?

Try GRBL post processor.

has anyone tried making a mastercam/solidworks replacement?

Mostly interested in looking at some code, not taking on the challenge lol

FreeCAD and its CAM Workbench?

For the light version maybe Solvespace?

I'm still amazed by Dune 3D: https://dune3d.org/ where the Github page has the footnote:

>I ended up directly using solvespace's solver instead of the suggested wrapper code since it didn't expose all of the features I needed. I also had to patch the solver to make it sufficiently fast for the kinds of equations I was generating by symbolically solving equations where applicable.

Dune 3D is made by the same guy who did Horizon EDA (https://horizon-eda.org/). A really talented and productive person.

Very nice thank you!!

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