Mirror / Lens upgrades

[Mike Syv]

Hi all,

I'm curious about replacing my mirrors and lens on my 50W laser. I've read some information on it, but am really wondering if the lens and mirrors you can get on Amazon are a worthwhile upgrade.

If it is indeed worth it, what can I expect in terms of improvements?

Also, one thing I've been trying to track down is what the ideal water temp should be for the laser? I have a 5Gall igloo cooler and aquarium pump that I use. I basically fill it with ice water and try to keep it as cold as possilbe. Not sure if too cold is an issue. I need to figure out some ice pack solution with distilled water as I'm changing the water once the ice water melts. I know it's not ideal.

Thanks all.

[sebastien laforet]

you can get quality mirrors and lenses on cloudray (https://www.cloudraylaser.com/, also present on aliexpress https://fr.aliexpress.com/store/1513187 ). they are probably not "the best" but very good and cheap.

you should not expect any real improvement if your actual mirrors are not utterly crap. probably at best 1 or 2% more power... you can get a real improvement (or mainly "restore" normal output) if your lens is dirty and not cleanable (*)

as for water temp, i have run as low as 12°c and no more than 25°c, and i never saw a difference in the laser output. you should just avoid setting temperature too low when it is hot and damp, as i might create condensation on the tube (and water + high voltage = not good)


(for example when your coworker failed to use correctly air assist and there is a large clogging on the lens that refuses to wash out even with alcohol rubbing)

[Gene Uselman]

Cloudray sells quite a few parts on Amazon in the states BTW.

[Mike Syv]

Thanks all for the tips. Good point on the condensation. I hadn't thought of that one. I'll have to check that one to make sure it's not condensing on the tube at all as the water does get pretty cold as I have a pretty high ice to water ratio.

Also thinking about some of the different focal lengths. I have the 1.5" which I believe is the default. If i go to a longer focal length, can I effectively cut thicker material in one pass with a more straight kerf? Is that the idea behind changing the lenses?

I feel I should probably know most of this stuff as I've had it for a few years, but only recently got it where I feel like the system is pretty dialed in...Prob going to lightburn next to see if some of my cutting mismatching goes away.

thanks again!

[sebastien laforet]

Also thinking about some of the different focal lengths. I have the 1.5" which I believe is the default. If i go to a longer focal length, can I effectively cut thicker material in one pass with a more straight kerf? Is that the idea behind changing the lenses?

that's the theory, BUT with a longer focal length, the "dot" size is larger so your cutting capacity may slightly decrease (as more matter shall be destroyed by a larger beam). you gain on the verticality of the cut, and also on the adjustment of the focal (more tolerant to not completely plane table). if you have a powerful tube, that's ok, but with a weak tube (say 40W), you may have to decrease speed to achieve the same cut, even for shallow materials where you will have no gain using a longer focal length.

be careful ; when changing focal lens, you probably have to change the nozzle and/or the lens mount in the head! otherwise the longer beam will hit the inside of the nozzle.

[Bryan Kelly]

I use a 2 inch-50.8mm focal lens, not sure, but I feel a good all around.. as for ice, I use freezer packs, put in a couple and add one here n there as needed, to maintain 18-20C, when done, take them out, wipe/dry them off, re-freeze...