CNCOLETECH CO2 Laser Lens Dia:15mm FL:2 or 50.8mm Laser Mirror CVD ZnSe Focus Focal Lens for CO2 Laser Engraving Cutting Engraver/Cutter 40W-200W

I bought a 2.0 focal length CVD IIVI ZnSe lens, 19mm diameter. This lens is thicker at the edge than OEM lenses from universal laser, but it just barely fits, and cuts well enough so far. I bought another one that is listed as plano-convex like the OEM lens, but it is out of spec and too thick to use. The plano convex lens from universal laser is about 2.3mm thick, and 1.75mm thick at the edge. One caveat, which may or may not apply to all replacement lenses, is that you will need to re-calibrate your height adjustments to match the new lens. This one works best for me when I change the calibration from the original lens and set at -0.100 and re calibrate. This makes the table a bit higher, and makes the laser focus tighter than if not calibrated. I made a bunch of test cuts, going first with the calibration that worked for the OEM lens, and moving the table up in 0.050 increments. the kerf got smaller, at .050, smaller still at .100, and then started to get wider at .150 as I raised the table above the ideal focal length.

k40 lasted 2 hours crap

Not a good discription

I had red reviews about the dimensions being off. Mine was dead on, as checked by my digital calipers.

This was a great replacement Focus lens for my 40 watt unit. I would buy it again

The product description claims this is 2.2-2.3 mm thick, however it is much thicker, like 3.2mm, which is a problem for mounting in a Universal laser cutter. I can sort of make it work by adjusting some things on the whole lens holder assembly, but thats not the greatest solution for my situation, since I run a space with 6 lasers that are used by hundreds of people and its possible the lens assemblies can get swapped. As far as the lens function, it seems to cut great, so I would give that aspect 5 stars, especially for the price. However the thickness is really a problem, and it would be fine if they accurately stated the thickness in the description, but the fact that the description is just wrong is hard to get over. In the image Ive attached, an original Universal lens is on the right, and this replacement lens is on the left, so you can see the difference in thickness.

Quality product. Far superior to lens supplied with K40. Certainly made a vast improvement on cutting and reducing burn.

12mm lense is head and shoulders above the one that came in my k40.

This was a great replacement Focus lens for my 40 watt unit. I would buy it again

12mm lense is head and shoulders above the one that came in my k40.