Hello,
Another software I use let’s you choose to cut on the line, inside the line or outside the line.
You can do this by setting a kerf offset for your tool, in device settings for example, then when you set the “Line” settings there would be an option of where to cut and the kerf setting would be applied automatically.
I’ll attach examples.
Would also be nice to see the actual profile with the cut line in the preview window.
I may be reading your suggestion wrong, but we have always had the option to determine inner or outer kerf in LB, this also applies to visualization of kerf setting in the preview window.
Already exists, except it doesn’t show you how the offset applies to the original shape.
Don’t see how it already exists in that link?
Unless you’re referring to applying a kerf offset manually. I’m talking about it applying it automatically by selecting either on the line, inside the line or outside the line when creating the toolpath. So the “line” settings would have those three options in the settings tab, your kerf would diameter would already be set in the device settings and that would be applied by selecting one of those 3 settings.
Yes I get it you can already set it manually but I’m talking about making the software better by having this done for you.
Make sense?
Except kerf with a laser is a fluid dimension. It varies based on speed, power and the material you are cutting. Therefore it needs to be adjusted for every project.
With a CNC, your bit diameter is constant, so a .250 dia. bit will always take a .250 kerf.
If I cut 3mm basswood plywood it may leave a .08 kerf, whereas if I cut 6mm solid cherry, it may leave a .11 kerf. (Theoretical numbers, but based on actual experience) See what I mean?
I would rather not have such an option. That is just one more setting that you have to think about. The manual kerf offset does what it needs to when you need it.
For the majority of my projects, I don’t need a kerf adjustment at all, only on boxes with slots and tabs, or if I did inlay work, which I don’t.
4 Likes
As the others stated, that’s already there. You go to the line settings and set the kerf to inside or outside. Simple as that. As @thelmuth already mentioned, there is no general kerf value for a device, additionally, the spot is usually not square but rectangular, that introduces another dimension.
The kerf of a laser is not fluid. That’s why the manufacturer tells you the kerf in the laser specs. If you’re getting different values, that would be due to focusing.
Thinking is good.
But for your example, you wouldn’t need to think or even look at that setting since “on the line” would be default. So in reality there would be no ‘extra’ thinking needed since if you’re setting a kerf offset you have to add the required settings anyway. The way I’m suggesting is the same except you just choose outside or inside the line and the correct settings are applied automatically.
Definitely no. First, no manufacturer tells you the real spot size, they are exaggerating to the maximum (or minimum). They tell you 0.08 where the real spot is 0.3 etc. That’s very common. Second, the final kerf depends on the material. A fiber-based material like wood burns differently than acrylic, for example. Even different sheets of the same material can have a different kerf. The thickness also plays a role, temperature etc. There are many variables.
4 Likes
This is CNC mill thinking. Although they both can use the same hardware, the “tool” is very different. A mill cuts a slot, a laser cuts a line(comparable to line art), referred to as vectors.
You did not say what other software. I doubt it was for controlling a laser. Was it a CAD/CAM?
Hi.
Interested in something like that, definitely.
Believe it’ll work, definitely not.
True to an extent with industrial scale lasers that have hundreds or thousands of watts extra power available (the matter is more or less evaporated rather than burned like we have to do), a “long” lens (DOF) and a largeish perfectly round dot.
A kerf system like that You’re describing was (possibly still is) a part of the manufacturer supplied CAD/CAM software on such laser systems.
The reason for less kerf fluidity on those systems was simply that the customers demanded that, it was after all the dimensional trueness of the pieces that were cut that mattered, not the means they were cut.
Our hobby lasers are totally different animals though.
In order to squeeze the maximum possible power density onto a 0 thickness surface to be advertized about, rather drastic measures have been taken, not to mention bending the truth.
And those measures make the kerf more or less fluid, while truth bending makes even the fluidity somewhat unpredictable.
More (actually a lot more) with low power visible wavelength diodes, less with higher power CO2’s and fibers.
But fluid to a degree in any case.
I do wholeheartedly agree that the fluidity of the kerf is a nuisance if and when files and designs are shared to be cut with different laser systems, and an automatic kerf compensation familiar for those in CNC machining world would be a neat feature would it work, but I for one can’t imagine what would be needed to ensure it actually worked as intended.
Or at least better than what we have at the moment.
The old but true Krusty Burger slogan IMO holds true in this case as well 
Regards,
Sam
A 0.250" bit will wear as the day goes on. I used to rout a lot of channels in phenolic material (with a ±0.001"), and would have to change the kerf width as the day went on. By the end of the day, the kerf was increased about 0.002" per edge. Tool deflection is also an issue, but can be alleviated by running the channels in the same direction.
This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.