Cracked lens, why?

[Craig Matheny]

I run a california air tools compressor " Ultra Quiet, Oil free with air dry and after cooler" this runs both my machines with plenty of air is quiet it is on the other side of a door and I can hardly hear it. Have not had any issue with water

[daniel coyle]

I have found the 63.5mm (2.5") lens to be best for cutting.

I 3d printed a bracket to hold a length of 1/8" aluminum tubing bent so that it aims the air assist directly at the cutting point 1/2" off the surface. I have a Gast compressor that supplies up to about 25psi. The original air assist connection to the nozzle is now open since the connector is removed.

The combination of longer lens, powerful (external to the nozzle) air assist and open hole on the side of the nozzle has had the result that I rarely need to clean the lens. I need to clean it so infrequently that it is difficult to estimate how many hours of cutting elapses between cleanings, the second mirror ends up needing to be cleaned much more often, about once a week if used daily. Most of what I cut is either 1/4" plywood or acrylic.

Great feedback generally. I put the 50mm lens in and it is doing ok and staying clean with the air assist on. It is still not cutting at quite the level I had anticipated/wanted and am wondering if, Rich (or anyone), setting up an air assist external to the cone with higher pressure would help my cutting of the cork and foam? seems like I would want to keep the cone air assist on as well to protect the lens? but you have had success with bypassing that system and allowing the hole in the cone to act a an excape for dirty exhaust? is that right?