I’ve been looking at the laser module whilst waiting for my A350 to ship.
I cannot determine from the information in the forum if the laser works in 3D space.
The specifications states a flat area to describe the laser work area, but it seems strange that once you’ve focused the laser that you cannot follow the work piece which you may have carved before with the CNC - meaning that you have a model of the piece.
Is there any documentation or experience on this anywhere that I’ve failed to locate?
Has anyone done this?
It does not at this point. The most it does is a step-down for cutting that lowers it’s height for each layer as the cut becomes deeper.
There’s no reason it couldn’t though. I haven’t played around to see, but I would think by taking g-code created in Fusion 360 for milling it would be easy enough to substitute the code for the laser instead of the cnc. Just need to figure out how to set your z-origin to match your focus point. (or height in Fusion)
In theory it’s no different than swapping out the cnc bit for a pen or drag knife.
Have to put that on my ‘to try’ list if someone else hasn’t already.
Thank you for that explanation, would love to hear how you go.
Reading between the lines I get the distinct impression that the three modules, 3D Printing, Laser and CNC are not driven by the same codes, but domain specific languages.
The specs say that 3D printing uses GCODE, Laser uses NC and CNC uses CNC.
Is that correct and is there a way to “translate” between those, or are they essentially the same with minor differences for different tooling?
Hello Onno; I suspect that what you want to do would provide too many challenges. The one that comes immediately to mind is the 2.5D representations offered by the laser beam. If you change the laser beam’s height in the Z axis, to replicate the act of CNC carving, it is probable that areas of variable height next to each other will leave scorch/burn/smoke marks on bits previously carved.
Secondary to that is that it can be extraordinarily difficult to represent anything in 2.5D with the laser beam in a single plane, where the workpiece is variable in moisture, hardness and surface. It is also not exactly clear what the point of focus is for the laser beam. I am currently awaiting answers from the Snapmaker team which can speak to absolute point of focus of the laser diode used and then the lens array used to change that to some manageable range.
I would be delighted to be shown otherwise but I suspect that for all practical purposes, the application of the laser beam to 3D carving is beyond the pocket of most hobbyists. You probably are going to be talking CO2 laser to get the wattage and the user controlled variability of the power of the laser beam during carving.
@jepho, thank you for your insights. I did see your comments looking for details on the laser and the lens configuration. I’ll be watching to see how your query evolves.
Are you saying that the power of the laser cannot be controlled whilst the job is running?
Hi @ITmaze; Yes… and no. I have been less than impressed with Luban as a piece of software over the last 6 months. It appears to be beta, at best, for some things like laser work and it has been acknowledged as alpha (in the dialogue box when it is started in CNC mode) for CNC work. It is probable that 3D printing is where much of the programming effort was expended.
Until I get some hard facts about the laser beam focal length and the lens array that is used with it, attempting to program any kind of Z axis movement is futile. (@Edwin @JKC20 - please note that the delays in getting these questions answered is difficult to understand… it feels as if Snapmaker don’t want my custom) Luban has been a source of more than mild frustration to me. I have recently moved my CNC work to Carbide Create, which is free, logical and very capable and I will shortly be the possessor of a Shapeoko CNC machine from Carbide.
I have only just moved my laser work over to Lightburn, which is not free but relatively cheap to buy at £31 and it seems to be very well thought out and extremely capable. It permits the beam to be fired at one half percent power while focusing the beam. I am too new to the software to have covered all of its capabilities but I am very hopeful. Each aspect of a pattern to be engraved can be placed on a different layer very easily and each layer can have its own specified power and movement settings.
I am writing about my experiences with it and have just started to produce a piece for the forum. Not to blow my own trumpet but you will be able to read it here: SM1 Laser (1600 mW) and working with Lightburn I will be adding to it as time and knowledge permit. It is hoped that it will then become a resource for people just starting with laser and Snapmaker.
technically the Laser uses the same G-Code as Milling or 3D printing for movement, i.e. the laser can move in all three dimensions, and it should be possible to “abuse” G-Code generated by other programs, if you are willing to dig in and replace the tool commands. I suppose in most cases this would be a tedious job, so it would be better if you find a program that supports it natively (I don’t know any, but I’ve just started using the laser myself). I could see very good reasons to have such a program: Imagine the object you want to engrave is not flat and you want to compensate for that. I myself did a bit of laser testing that involved moving laser in Z, and I can therefore confirm that the device accepts Z-movements in laser mode.
I get that the code is essentially the same, @Hauke . The software I am using includes a component for rotary movement so that round things can be engraved. I was trying to address the general question from a Luban point of view for @ITmaze, then I tried to expose some of the issues that 3D laser work entails. I am sure that a layered approach may help to provide an interesting intermediate diversion, where every section can be placed on its own layer with its own power and movement settings. Lightburn permits this and the sequence of cuts can be placed in any order.
In some senses we were previously looking to understand the nature of that possible variability of power in relation to greyscale and dithered images here in this particular forum thread. Laser: True grayscale instead of dithering?
The attraction of an infinitely variable power sourced laser would be that it could help to permit better engraving of images. Turning the power of the laser beam up and down, in response to computer bits increasing or reducing in value is not the problem. Doing it very rapidly may become an issue depending on the hardware limitations placed upon software solutions. Doing it for portions of workpiece that are spaced at intervals just 0.1mm apart from each other, with a laser beam that is projected through an imprecise optical system, may mean that your efforts would be wasted before you begin.
A very precise high quality optical system may permit very close placement and approximation of each ‘bit’ of laser energy. The workpiece material will have to permit surface temperature changes that cannot and will not migrate to the next closest area if your 3D laser carving is to be a practical reality. As an aside: it looks as if fibre based laser cutting is superceding CO2 in terms of precision and wattage.
The link details machine specs with 500 ~ 3000 watts of energy. https://www.durmark-machinery.com/High-Precision-Laser-Cutting-Machine-Laser-Cutter/
Interesting to note that 90mm is the workpiece height for all of the machines mentioned. Most homegamers are going to struggle to accommodate machine weights of around 4.35 to 6.25 tons, even if they can find the space and the money.
Here is a screen-grabbed specification sheet for the Durmark machines:
Edit to say: I hope Durmark’s machinery is better produced than their typing.
Definitely could edit cnc g-code and would be able to make it work.
Whether the result would be worth the effort is questionable.
Just need to change the .cnc to .nc to make it accept it.
Here is start of cnc (not including some comment/header stuff):
G0 Z10.00 F120
G0 X-60.00 Y60.00 F120
G0 Z5.00 F120
G0 X-60.00 Y60.00 Z0.00 F800
G0 X-60.00 Y59.90 Z0.00 F800
G0 X-60.00 Y59.80 Z0.00 F800
G0 X-60.00 Y59.70 Z0.00 F800
G0 X-60.00 Y59.60 Z0.00 F800
G0 X-60.00 Y59.50 Z0.00 F800
G0 X-60.00 Y59.40 Z0.00 F800
G0 X-60.00 Y59.30 Z0.00 F800
G0 X-60.00 Y59.20 Z0.00 F800
and here is a bit of laser:
; G-code START <<<
M106 P0 S255
G0 X-21.05 Y-22.80
M3 P50 S127
G1 X-20.95 Y-22.80
G0 X-13.60 Y-22.80
G1 X-13.55 Y-22.80
G0 X-6.10 Y-22.80
G1 X-6.00 Y-22.80
G0 X1.35 Y-22.80
G1 X1.45 Y-22.80
Both files use the same commands to move the toolhead, although they go about it slightly differently. Laser has a Z0 as it’s z height (which I assume corresponds to auto-focus calibration) and then adjusts from that point for multiple passes at start of pass. CNC gives z for each movement.
Big difference is when and how often they turn the toolhead on. Laser is alternating moves with laser on & off.
But I think most of it could be edited with find/replace and made to work.
Whether all those adjustments would be accurate enough to provide an acceptable result would take some testing.
As much as I love a challenge I can’t think of a project I’d need it for at this point and not worth the time to me at this point.
With the right post-processing file you could have Fusion 360 create the tool path automatically, (not sure if it would only do 2D) but that’s beyond my understanding at this point.
When I read the title of this post, I immediately thought of a CNC video I watched on you tube recently: Carving a Bald Eagle (I set the time to the finished product near the end of the video).
@sdj544, that’s the sort of project that I would want to use CNC and Laser Engraving together on.
I think it should be doable!
I’m relatively new, but here’s my thoughts.
- Slice the 3d form into layers as if you were making a stackable cardboard 3d cutout.
*using a program like “Slicer for fusion 360”
Each layer will be a ring that is all the exposed surface area of your object at a specific height.
The layer height will be decided upon you by how close in density you want your laser engraved lines together.
It will look like a topographical map of your object.
- Compile each sliced layer as your z-step.
You may have thousands of layers depending on your density of fill. In luban the fill density is caped at 20 dots(lines)/mm. if you have a 10 mm deep 3d object at max density, you will have 200 layers.
Lightburn has max "Line Interval of 0.010 lines/mm. And at that density for a 1 inch deep 3D relief, you will have 2540 layers or z heights to compile.
Your laser depth will be limited by the proximity of the relief higher up. If a higher level hits either the ring or the laser housing, it will not go down further in any valley.
If someone thinks this will not work, I’d love to hear why.
I’m not set up at the moment to test this out.
This software appears to do curved surfaces
Combined with the community regex/postprocessor that should be a viable option.