Crashing in CNC mode

I’ve used the Luban CNC mode with an a couple SVG images that have worked out more or less like I wanted (assuming I’d actually chosen the bit that I told Luban that I was using). So today I tried something a bit different, using a png image I wanted to do a relief “print” to put a half inch round bevel on a piece of wood. I can load the image into the editor without any problem and when I press process it goes to the process page without any issue. I set up the parameters and find that apparently it won’t let me generate g-code with first doing a preview. I do the preview and after hanging for a couple minutes saying “Generating Tool Path… 0%” Luban crashes.

Here’s the image I’m working from:

Doesn’t crash mine with default settings.
But I don’t know what your settings are.
You have to share your settings if you want help.

The file only shows left and top beveled when I open it, and in Luban preview, but the g-code shows all four sides.


Sorry, here are the settings I used. Figure scaled to 228.6mm x 304.8mm (9" x 12")

A couple of points: The target depth is set to 8mm and your step down depth is set at 0.5mm. You will need 16 passes to complete that instruction so you need to click on Multi-pass and set that number of passes. As it is; your settings will only permit a single pass of 0.5mm. The density setting of 5 will leave you waiting a long time for each pass to complete. Your mill bit is presumably 3.175mm in diameter.

Half of that diameter is 1.59mm and a density setting of 1 equates to the mill bit moving sideways after its cut by half of its diameter. If you were to set a density of 10, the mill bit will move sideways by 1/10th of its diameter. This would mean going over previous cut areas too many times just extending machining times unnecessarily.

Okay, apparently it was the fact that multi-pass wasn’t checked that caused the crash. I’ve got the g-code now but I’m not quite sure what’s being cut.
So, a related question, for CNC purposes does the white area of an image indicate removed material or the black?


It depends on whether ‘invert’ is checked.
If checked white is lower.
After you load the gcode to the workspace you can tilt and zoom the preview there and double check that its doing what you want.


So, I rescope my test project because of clamp issues. The second try was just a 6" x 6" piece with 0.25" round bevels. The g-code generated fine but it’s got to be just about the most inefficient code possible.

Using these parameters:

It produced code that does this (and will supposedly finish running in about 10 days):

I’d post the g-code equivalent but it weighs in at over 38MB.

Is this just an artifact of the way that Luban handles relief images?


My guess is that it is the software. Try Carbide Create. Free, logical and highly recommended if you want to do CNC.

I designed my own clamps that are easy to use and give you a lot more room.

Yeah, another great piece of software that won’t run on my 11 year old but otherwise still very functional Mac Pro. :frowning_face:

VMware is a wonderful tool :wink:

I’ve been running MacOS for many years, but I prefer Linux as my desktop and I have clients who demand that I use their MS environment to solve their issues, so I installed VMware over 20 years ago and have never looked back.

Now I just create a new VM every time something needs installing. Disk space is cheap.

I agree with @ITmaze on using some sort of VM software. The age of your machine will preclude much software that is helpful. Have you considered buying and dedicating a cheap PC to the tasks you want to complete? I dislike the idea of using an OS like Windows, that is unhelpful in so many different dimensions. I started learning computer use with a Mac IIci and system 7 in the early 90s.

I don’t particularly care for the current direction that Mac OS has taken and preferred the earlier varieties of OS X. My MacBook Pro dates back to 2014 and it is starting to show its age. Linux is nice to use and the Unix underpinnings give it functionality and configurability.

With a Win2k machine, I started out with an early iteration of Slackware’s Red Hat Linux and used Motif as my X Windows desktop. The joys of configuring the Kernel! Today, MacOs has its foundations deeply rooted in BSD Unix so it ought to be usable with many varieties of software and open and free foundation software is probably where you will get the most help.

It speaks volumes to me that Luban runs on your 11 year old Mac. Rather than praising the robustness and longevity of the Mac (which has been absent with the passing of Steve Jobs in my opinion) I suspect that Luban is constructed in a manner that is not on all fours with current programming methods.

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luban does nothing but crash for me when i try to use large files. not that fusion is taking away the milling feature im not sure if ill actually be able to use my snapmaker. I have been struggling with using the cnc part of the software.

Try something else. Carbide Create id free to use as explained above or Easel, which is online and very easy to drive. Fusion is going to change its use very soon, if they have not already.

That’s not the point. Snapmaker is pushing fusion 360 because their LuBan was not designed to handle laser or CNC. We get that. But they need to fix this software. It crashes bad. It’s not my computer ha ha lol we hear that all the time. Trust me though it’s not I have more then enough overhead and resources. We shouldn’t need to look for other software to do simple tasks.

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Yes, I agree with you @Gysnst2. Unfortunately I have been saying that Luban is inadequate for a long while (at every opportunity) and there is nothing being done about it. The CNC segment is alpha software and proudly states that when you try to use it! I have written about that aspect in the Lounge and other threads. The rest of Luban is barely beta software and it is a mystery to me why team Snapmaker feel that they did not need to support the hardware with a decent software offering.

I have been able to run Carbide Create and it it is very capable for simple tasks (2.5D) and I am now a convert to Lightburn for the laser work. It is 3D capable. I conclude that Luban will remain poor because the attitude of the team Snapmaker folk is use Fusion 360. It is a pity but the software not supporting the hardware is a mistake and the company will run out of sales steam.

I have just bought a Carbide machine (Shapeoko) rather than SM2 because the Luban software is so very poor. I do not see sufficient evidence of the commitment to either bin it (it is dire) or improve it. In my view Snapmaker team should buy in the programming skills to rewrite Luban from the ground up.The Lightburn development team is just two people and they are very responsive to their forum of over 7,000 users.