Yesterday I wrote about issues I was having with mirrors on my laser cutter. I mentioned that I couldn’t get to the lens to inspect and clean it up. Well today with help of some great CNCZone forum members I finally figured it out.
Below Owen Hedger’s video on how it’s done. I’m also adding my own comments and photos after that.
My head assembly looked slightly different (it’s black, air assist connector also different design and I have mount of laser pointer) bur other than that it’s identical.
Issue with mine was that it was screwed in extremely tight, and no way to unscrew it with bare hands. So I after taking off laser pointer and removing air hose from push to connect valve, I removed whole nozzle assembly. It’s easy to remove by unscrewing it from under the 3rd mirror holder. Had to lower my table to take it off.
After that I removed push to connect valve, wrapped head in some cloth and using two small pipe pliers was able to unscrew it. Cloth didn’t prevent me from stripping some paint 🙁
I immediately noticed that when it was screwed in at the factory, they did it so hard that aluminum color holding lens cut into the metal above it. There was ton of debris and oil.
Aluminum color is what’s holding the lens inside the nozzle. It was easy to unscrew by hand. I inspected and cleaned the lens with 99.9% Isopropyl aclohol and cotton swabs.
I also cleaned all threads and inside of the tubes to remove oil and metal shavings.
Lens itself is 18mm diameter with focal length of
43-45mm (I got focal length information from person who posted the video above, but I guess I can measure it myself someday) 2 inch or 50mm (I finally measured it myself).
Then I just assembled everything back together.
Note: Make sure you place lens flat side down and convex side top. I actually made mistake of installing it wrong way and couldn’t cut anything 🙂