Alignment issue or something else?

Hello,

If someone has a moment, I would really appreciate some input. As the picture shows, I’m trying to cut two shapes out of a block of wood. I have tried numerous times unsuccessfully to cut the shapes out of the word in the manner in which I have laid out on the screen. The cut shapes always end up being off to the right as seen in the photo. I’ve tried print and cut. I have tried setting the origin from numerous points on the laser cutter. Still unable to get this to cut the simple shapes correctly including the center of the registration marks and still the same result over and over. If anyone has any idea what I am doing wrong I certainly would appreciate a helping hand. Thanks in advance.

The green square is what Lightburn is using as the origin…

What is ‘start from’ set to under the lase window…?

I have never used cut/print but I deal with jigs on most of my work… I also use absolute for jigs…

Is the outer line a ‘tool’ layer ?

:smile_cat:

I changed all objects to tools with the exception of the cut outs. The start from is set to user origin. I changed it to absolute and got the same result. The cuts shift over. The attached pic is in user origin. As you can see the green dot shifted to the cut out, but when I run the job the finished piece still prints off center. I use the laser printer to set my origin on the registration mark on the left. Every solution I try include resetting laser brings me back to my cut outs being off center in what appears to be a centered cut.

I am probably missing something here, but why are you using print/cut?
Are you trying to set your cut to a specific position?

Are you using a head-mounted red dot pointer to align with the registration marks? Is that pointer exactly in the same place as your actual laser beam?

Unless it’s in your ‘work area’ at the exact right location, you should get different results…

You do have to ‘re send’ the file to the laser…

:smile_cat:

Yes, I am using the head mounted laser to set location. Yes it is in the exact location of the center of the registration mark which is also on my pice of wood I am cutting. The only reason I was trying print/cut was because I was unable to successfully complete the cut. I thought perhaps it might help. As to “start from” just trying all of the different variables so see if I get intended result. Yes after each iteration in changing the laser setting I send an updated file to the laser.

Is there an offset for the alignment laser?
If so, did you set that?

Yes there are offsets. I have redone them twice just in the event I missed something the first time. I’m uploading the file. Mabye someone can see something I can’t. Just to reiterate the piece of material that I am cutting has a registration Mark in the upper left and lower right hand corner which I used to make sure my material is in the correct position for the laser. I’m gone so far as to delete the registration marks and the bounding box representing the material to be cut in an effort just to isolate the center pieces which I’m trying to cut out of the material. Still no luck.
PunchOut.lbrn2 (19.5 KB)

Couldn’t you just use framing to align the material?
Unless I am missing something, it seems you are over thinking this.
With that file I would just align it with framing. I have saved positions for most everything I do and use centre job origin. Saved positions are to the centre of my material.

I use the red box as a tool to represent my material and the I use the alignment tools to center mu cut pieces in the middle leaving equal space for height and width. For whatever reason my laser is not cutting what is on screen. At least not on my laser. I’ll be the first to admit I could be aligning incorrectly but this is the first time I have had this problem.

This thread is a little confusing because you keep changing the conditions.

In the original annotated screenshot what you’re getting is pretty much what I would expect. If you have your origin set to the center of the registration mark but the origin indicator is on the top-left of the border area then you would expect the burn to shift down and to the right the distance from the green square to the origin location.

Trying to use Absolute Coords should be an entirely different game and should be very straightforward. It should burn where the material is located on screen. Are you saying this doesn’t happen?

I think you are doing everything correctly, but I’m not entirely sure if you confirmed whether or not the spot from your head-mounted visible alignment laser is in perfect alignment with a pulse from your laser - it has to be in alignment in order for print and cut to work.

My guess is that your visible pointer spot is slightly to the left of your main laser beam (and is probably travelling over the previous cut perfectly).

YES!!! Your comment and several youtube videos have me checking that very thing this morning. I will get let you know the outcome of that. Thanks for the tip.

Laser red dot alignment out of alignment. 3-5mm is my best guess. Which is about the amount my cut is off. Thanks for all of the help from everyone who answered.

BTW is there anywhere in Lightburn that tells you where your laser (current origin point) is in relation to the table? Coordinates?

Is this a new laser for you? 3-5mm between red dot and laser dot would be a surprisingly large gap not to notice. It sounds like you have one that’s mounted on the head at an angle. Keep in mind that red dot alignment in that case is only good for one focus height.

Two things to try:

  1. Enable the “Show Last Position” button in Laser window. That should create an actual cross on the Workspace of the last position of your laser
  2. In Move window push “Get Position”

Yes, the laser is only a few weeks old. Thunder 63. Burn test was spot on, yet red dot was out of sync. Lasers are great, but there is a lot of OTJ learning that comes with it.

I’ve had similar problems when the zero point wasn’t in the bottom left corner. However, I only have a small cnc3018 plus. But I would try to set the zero point to the lower left corner (coordinate 0,0). Then draw a rectangle of defined size and write an nc file; you can read it with a text editor and calculate whether the position and size of the rectangle is correct. Since I’ve been doing this, it’s always true.

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