I have used the laser offset feature many times on it’s own, and it works well. But recently, when I tried to use it in conjunction with print and cut, it was not working. It was as if the offset was not being taken into account.
Some of us with diode lasers need to use an external cross hair pointer due to how the diode laser module is constructed which shields the laser from exposure, and thus makes it impossible to see the laser dot to make alignments.
I have seen a few posts on here and here about this, but none of them have been ansered. Is this bug on the to do list?
To use this you need to install a laser pointer in your laser module.
I don’t know if you laser module has one already equiped, but if not you need to install and set the pointer offset.
I’ve struggled with this same issue a bunch - basically the laser module shielding makes it very challenging to see where the laser hits the target. For me this is especially a problem when the target is close to the y-axis origin, because the laser (Ikier K1) frame blocks the module “window”.
My work around has been to lift the z-axis out of focus and fire the laser, the end results are not quite as precise as using the focused laser to position. This is mildly annoying, but works for me. If you don’t have a motorized z-axis then you would have to manually lift and refocus the diode and then home before / after to make sure you didn’t move the laser accidentally. I don’t think this work around would work if you don’t at least have limit switches to get an accurate home.
To make things easier, I have purchased (but not yet tried) a little wifi “spy” camera which has a tiny camera on the end of a ribbon cable. My plan is to mount the camera inside the laser module so that I can see the laser fire and hit the print and cut target. I do not expect to use this camera from within LB, but even having to use it from a separate phone application will hopefully make this process more accurate and convenient.
I’m not sure how long this camera will last due to heat and smoke/debris, but it was about $30 which I regarded as a reasonable cost for the experiment. If I have success, I will report back here.
I tried to make offset targets (think something like an Ankh with a circular target that would center the laser with an external cross that could be lined up with the cross hairs O–+) that I could use the cross hairs to set the locations, but I think there might be rotational issues that would affect accuracy. Additionally losing the ~50mm of work space meant that I would have to do an extra burn (3 instead of 2, 4 instead of 3) and I gave up on the idea.
I couldn’t put it better myself!
I’ve also considered cutting my laser modules’ front face so that I can see the dot, but that would mean I would have to invalidate the warranty… not ideal.
It would great if the LB devs could incorporate the offset into the print and cut feature… hopefully they will look into it soon enough. And on that note, how do we raise a bug request for this?
I also have a sneaky suspicion that the offset won’t work with a rotary tool either… might have to check that later.
This is how I actually do and what happens time to time.
Only problem is, my laser focal point is 0.08mm so, many times when cuting the end point of the cut don’t match with the start point. Thinner edges cut thru also.
In my opinion this will work fine, but only while the camera lens still clean and don’t get burned by laser reflections. If the camera is assembled too close, laser beam reflections will burn camera.
I am thinking more in a external laser pointer and use “laser offset” feature.
In addition to this you should have into account it will happens laser beam reflections from there. If those reflections accidentally hit your or someones eyes,… some reflections can blind a person instantly.
That protection is so, but so annoying, but at the same time so useful.
I thought it also worked with this function. But since I’ve never used it…
But you can leave your suggestion thru https://lightburn.fider.io/
My comment about “rotation” wasn’t for a rotary. I think this plan doesn’t work because the offset has to be exactly inline with the center p&c marker. If the material is rotationally different, then the distance (and direction) from the p&c marker center to the offset pointer changes.
Consider a laser offset pointer that is exactly 1" offset on the x and 0" on the y axis’. Now as long as you can keep your board perfectly aligned on the y axis then you could use the offset pointer to determin the P&C center - it’s 1".
But if you rotate the board at all - now you have an x and y offset - at 45 degrees (obviously not a real case), your offset would be ~.71" on the x axis, AND ~.71" on the y axis.
I haven’t worked through the math, but given that Lightburn should know where the markers SHOULD be relative to each other I think this could be computed…
In short, I think the idea is sound, but I couldn’t just print out a shape and have it work (that would not take any angle change into account)
Ah ok, I see what you mean.
You’re right, some diode lasers have a rectangular output in that the x-axis is not the same as the y-axis, and this results in inaccurate cuts even if kerf value has been set correctly.
This video shows a good explaination of this, and how to work around it. Hope this helps