What is typical laser lens life and other lens related ?'s 2

[gewing]

Hello,
I am running 2 Mazak sheet lasers. 1 2.5kW and 1 2.0kW. Both machines are the STX510 S/C. We are using II-VI ZnSe Plano Convex lenses, 5" focal length. We run both machines around the clock 7 days a week. We cut mainly 16 gauge mild steel. Occasionally aluminum and S.S. We noticed that the lifespan of the laser lenses in our laser tube cutters is far longer than the lenses in our sheet cutters.

1)How often should we be cleaning the lens?
2)What is the average lifespan of a sheet laser lens?
3)Where can you get laser lenses refurbished?
4)Do refurbished lenses last as long as brand new?
5)Are there benefits to running a Positive meniscus lens instead of Plano Convex?

Thanks everyone for your input!

 

[msandoval]

The lenses in a flatcutter see more action than a tubecutting machine first and foremost. Most OEM recommend cleaning the lens once at least every 8 hours.

5" Focus Lenses usually get hit quicker with spatter because they are closer to the nozzle and if piercing parameters are too aggressive or not optimized this will create a lot of spatter and eventually hit the lens. There is no way to predict how many hours it will last (I used to tell customer it could last you as little as 2 minutes (reflection) or as much as 1000 hours (mainly cutting thin steel). Reflection from aluminum (yes, I don't care what anybody says, aluminum reflects and can kill your lens), copper (mirrors are made of copper), not cutting through stainless (welding on top of the material).

1. Once every 8 hour shift would be the least
2. Depends on what you are cutting and also the mode of the resonator (prefocusing will destroy lenses as well)
3. Laser Research Optics
4. Not really but they are cheaper
5. The meniscus lens will probably give you a bit more speed on thin materials (small waist) but the plano convex will probably be better on thicker materials (longer waist) and they are cheaper since they don't have to be ground as a meniscus. Also, the OEM's usually design their system with one lens in mind, so you may check with Mazak first and see if they have experienced with this type of lens.

Hope this helps.

 

[laserman16]

I'd also recommend you use one of your older lenes to dedicate for S/S and Aluminm. These materials tend to have a larger impact on the lifespan of the lens.

We applied this in the shop I worked in intially and found it improved lens life overall. We use one lens for hr/cr etc and then another for s/s and aluminum.

This way when cutting s/s you don't have to worry about doing any damage to a newr lens used for hr processing.

 

[JayMaechtlen]

This may be obvious, but here are some factors that affect the lens:
1. how much power it is transmitting.
2. how clean it is, and how good the surface is.
(3) how reflective is the material being cut.

Combining (1), (2), and (3) determines how much power the lens absorbs, hence how hot it gets.
The hotter it runs, the shorter its life is likely to be.

How quickly does it get dirty? Depends on loots of factors, like Mayron mentioned above.

how close is the nozzle to the surface when piercing?
how large is the nozzle orifice?
how often does it pierce? (lots of holes and features, or mostly long cuts?)
What piercing parameters? (gas pressure at pierce, beam intensity at pierce, etc)

Lots of factors- ympwv.
(your mileage probably will vary)

(Mayron- please contact me?)
cheera
Jay




Jay Maechtlen

http://home.covad.net/~jmaechtlen/