I have made many cuts of 3mm MDF wood, with the following configuration:
Speed 820mm/min
Passes 1
Power 100%
Air assist activated
But now suddenly it no longer cuts the same, I have had to lower the speed to 500mm/min so that I can cut exactly the same design with the same wood. Why? I don’t understand what is happening.
I have disassembled the entire laser head to clean it, but the problem remains the same. When I bought the 40w laser module it came with a part like a replacement lens. What is that or what is it for? What is the lifespan of that part? I have been cutting with the described configuration for about 8-9 hours until it started to fail, it doesn’t seem like a long time to me.
What I write is not based on personal experience, so please take with a grain of salt.
If you say it’s the same wood: Is it really the same piece of MDF, or another piece of the same brand? I ask because the glue they use in plywood or MDF can or cannot be good to be laser cut - so even the same brand may have variations. The exact same piece however I’d say should be consistent… I yet never cut MDF, but considering how fast and easy the 40W cuts plywood, 820mm/min is already slow and for me an indication that you have very resistant glues in your MDF
The lens protector that comes as a spare with the 40W is indeed a wear-and-tear part, as this lens gets dirty over time from the fumes and degrades. However, 8-9 hours is IMHO very fast degradation, which may hint on the fumes from your MDF being aggressive. If you put the used and the unused lens protector side by side: Do they look very different?
All that said, of course another option is that one or more of the laser LEDs have failed and the absolute power of your head decreased due to that, which would be a warranty issue.
My recommendation would be: Exchange the lens protector, try again with a piece of scrap MDF from the previous jobs. If it is OK with 820mm/min, choose some other MDF - the fumes are aggressive and might even be hazardous to your health. If with the new protector you still need to go at 500mm/min: Contact Snapmaker support, I’d assume that you have a faulty unit.
I have changed the lens protector and cut another one from MDF from the previous batch and another from the new batch, and I cut everything without problems at 820mm/min.
So the problem was with the lens protector, I have only lost an afternoon of my life and some wood hahaha.
The lens protector that I have removed I do not see visually that it is so dirty or in bad condition that it would not cut.
The questions would be.
What useful life should the protector have?.
Can the protector be cleaned and used again? How should it be cleaned?.
Is this replacement protector expensive to buy several?.
If the MDF glue is so corrosive, what other type of wood is better in 3mm to make Christmas balls, models and small figures?.
Expected life span: No Idea, would be a question to Snapmaker support.
Can it be cleaned? Yes: https://wiki.snapmaker.com/en/general/maintenance/clean_laser_lens_protector_of_10w&20w&40w_laser
Is it expensive? A set of three sets you back 10€: 20W/40W Laser Lens Protector Kit For Snapmaker 2.0/Artisan/Ray – Snapmaker EU
Is MDF corrosive? The answer can be all over the place, because it depends on what glue the manufacturer actually used. It seems that there exist plywoods and MDFs specifically made for laser cutting - a Google search should set you up here.
What other materials? I guess MDF is quite OK - I personally like plywood more, because it looks like wood with grain etc., but plywood also has glue, so same problems.
Just had a similar issue - I’ve had the 40w laser for a couple weeks now. Cut MDF, walnut, and maple no problem. Halfway through an MDF cut and engrave today and the laser just stopped cutting. After some investigation, soot had built up blocking the laser path and also filmed over the protective lens cover. I have thoroughly cleaned everything and replaced the cover because cleaning it did not bring it back to the clear state of the spare.
All that to ask: How do you personally set your height for the laser? I’m troubleshooting why this happened so quickly (4 hours of use) and trying to see if we are doing things the same.
I calibrate the laser height with the bed, without material, using the calibration mode of the configuration. Then, when I send it to cut, since I know the height of the material, I set it to 3mm in this case. I understand that it is the correct height. How do others do it? It could be a problem with that. I changed the protector that came as a replacement and had the same problem. After 6 hours of use, it already asks me to change it for another one, because it is impossible to clean it properly. It is clear that something is wrong and I do not know how to fix it, without buying hundreds of protectors.
I was calibrating mine in a similar manner. However, I tried the focus lever calibration and it gives a different height. I’m wondering if our laser nozzles are too close to the material and not allowing the smoke/soot to escape before filming over the protective cover. I will test with a new cover and increased height and see if it lasts longer.
