I have been cutting a specific puzzle for a couple of years without any issues. In the last couple of months or so, this puzzle is not cutting the same. The pieces usually fit in different configurations, but now they are no longer interchangeable.
I clean the mirrors and lenses in the morning before I use it. I had a basic and it cut fine. I have a HD Pro and it used to cut fine. Is there anything I can adjust to fix this issue? This puzzle was one of my popular items.
Kerf is determined by the material and by the settings you use.
Have you changed your materials or settings?
No. The material is the same material I’ve been using. It’s even the same batch. I use the same settings every time. Maybe kerf is the wrong word to use. Laser diameter might be better. At first I thought I might have inadvertently glued the border wrong, but I’ve tried 6 times now and the pieces are so close to fitting, but not without sanding the edges.
It’s really strange for your kerf to get smaller.
If you have your lens in upside down it can cause the beam diameter to be larger where it hits your material. This is the opposite of what you’re seeing.
If your auto focus system reads a different height for your material then it used to then theoretically it could cause the focus point to change and you might see a kerf size change as well.
In general using less power leads to smaller kerf size. If your overall power level is dropping for some reason it could potentially explain a smaller overall kerf. It’s possible that in the past you were using more power than was absolutely necessary to get through the material and you had a wider kerf as a result.
You sound like you’re pretty seasoned at using your laser, it seems almost silly to suggest that you’ve missed some sort of cleaning step. It sounds like you’re dialed in… But it is possible even after doing this million times to miss something. I would go through the official cleaning instructions just to be sure that you haven’t missed some step. On the performance models there are seven critical things to clean for optimum performance. If you don’t know those seven spots off the top of your head I would suggest reading the cleaning instructions just in case.
You say that it’s the same material, but materials change. If this isn’t an actual same piece of material that you’ve used, I would be curious to see if you get the same results on a different sample of the material, especially one that you’ve used before. Take something like Baltic birch — it can vary greatly from sheet to sheet, the thickness can range enough that your settings need to be adjusted. You are making puzzles so it’s possible you’re using chipboard. Chipboard tends to be consistent but it’s not all made the same so it’s possible that if you have a new batch even from the same distributor it could be a different overall material.
if you do go through a new cleaning step and try other tests and find that it’s still not fitting I would probably go back and see if you can replicate that problem on other materials as well. If you can then you’ll know that there’s a power problem with your machine. Over time the performance models will lose power, it takes quite a while but it might be that you’re at that stage if you’ve had your laser for a long time. It’s not great news but it is possible.
Good luck. This kind of issue can be really difficult to track down. If I had to guess I would say that the most likely candidates are focus issues and overall power decrease either from fouled optics or tube life.
The official cleaning instructions are linked in number 17 on the FAQ:
Another possibility is if the material is wood, it can absorb humidity over time and that can change the kerf.