Issues with cutting through materials

[jeffokelley]

I am experiencing a problem that seems to be getting increasingly worse. I’ve read through other posts but can’t find any tip I haven’t yet tried.

It started with having issues with cutting thicker material such as 1/4" walnut plywood. In the past, I have been able to cut with no problem but is has become hit-or-miss lately. I thought that maybe it was just the material but now I am having issues with thinner material. Today, I had issues cutting light basswood. I’ve attached a couple of pics to show what I mean. This happened when using the Proofgrade Cut setting (224 speed, full power). I had to slow it down to 200 speed to get a clean cut.

I’ve tried all the tips I can find. I’ve taken the machine apart and cleaned every component including removing the carriage, cleaning the air assist fan, and all the moving components. I cleaned all the lenses and the mirror and vacuumed out the exhaust fan. I made sure the materials were completely flat and even used a few pins to make sure. I’m using Glowforge Proofgrade material. Still running into issues. I’m not exactly sure where to go from here. Any suggestions or ideas would be greatly appreciated.

[rbtdanforth]

There is a window here that is sometimes missed:

but the slightest crud on it will cause what you are seeing. In addition, if the cut is impefect and a bit of fiber is likely to hang out it is better mess up the scrap side that the good side. I also keep a scalpel knife for when there is little such “almost cuts”

[jeffokelley]

Thanks for the tips. I did clean this lens as well. My question is, at what point do I need to consider replacing this and the main laser lens? Is it possible that smoke and such might damage these lenses?

[rbtdanforth]

It is possible for the laser to heat up the crud on the lens to thre point it damages the lens/window, though usually before that the baked-on crud just needs a more vigorous rubbing and be pretty obvious as in this case…

If a lens is damaged, it can be replaced from the Glowforge catalog

[jeffokelley]

Thanks for the input.