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View Full Version : Are Chinese mirrors and lens good?



Peter Jones
08-12-2012, 1:25 PM
I am reading conflicting stories on this. Some say there is no major difference between the Chinese stuff, and some say there is a big difference.

Has anyone replaced their Chinese with better ones? Got any details around the difference (cut speed/power) and durability data?

Lucy Lee
08-12-2012, 10:14 PM
most Chinese mirrors are made of silicon (Si) with many different coating on its surface. There are tmainly wo types for 50mm and 63.5mm. The reflecting rate for them is 99.85%. The mirrors can increase the cutting speed obviously.

Best Regards
Lucy Lee
G.WEIKE LASER

Bruce Dorworth
08-12-2012, 10:32 PM
Has everyone seen the link(on this forum) about making your own mirrors from hard drive disks? If not just search for mirrors hard disk.

Bruce

Rich Harman
08-12-2012, 11:38 PM
I have a couple methods for coarsly evaluating the "goodness" of a lens or mirror.

The job of the mirror is to reflect - and not scatter. The more it absorbs the hotter it will get.

The job of the lens is to let the IR radiation pass through - and focus. The more it absorbs the hotter it will get.

After running for extended periods at full power both the mirror holders and lens holders are cool enough to touch. My air assist is routed outside the nozzle so it provides no cooling. For the mirror holders I can detect no heat, the lens holder does get a bit warm but not hot. Some of the heat is going to be from the fact that it is so near to the work piece.

Another thing I do is lower the table several inches and fire the laser at a piece of thermal paper. If the spot it makes is an evenly filled in disk then you know that the mirrors and lenses are doing their jobs well. If it is a donut then your tube is could be on it's way out and if it is any other shape then either the lens is damaged, installed incorrectly or it needs to be aligned.

I too would like to see a comparison between the cheap and expensive lenses. My feeling is that the difference, if any, will be slight.

Rodne Gold
08-13-2012, 2:24 AM
The $30 ZnSe lenses I got from china work as well as the $500 replacement I got from my GCC agents. There might be some drop in quality , but we can't see it.
Evidently these are "imported" lenses according to the suppliers , imported from where is the question.
I doubt it would be worth your while to buy much more expensive optics, I would rather spend the money on spare optics and different focal lengths.
None of our cheapy mirrors get at all hot over extended full power cutting/engraving.

Gary Hair
08-13-2012, 10:31 AM
Rodney,
What diameter lenses did you buy for your GCC? All I can find is 19.5 or 20 mm and I want to get the best fit. I have a ZX like yours.

Gary

Rodne Gold
08-13-2012, 12:04 PM
I bought 15mm diameter lenses for my spirits , had spares for my Explorers
My staff, no matter how I train them , can really mess up lenses with heavy handedness. I caught one of my guys spitting on a lens and using toilet tissue to clean. (He is no longer with us- I mean the co)
They dont seem as robust as the OEM lenses , we have gone thru about 2 over 3 machines in the last year , but at the price , who cares..... :)
I bought 9 of them...

Peter Jones
08-15-2012, 2:13 AM
Thanks for sharing the knowledge, will probably pick up some cheapies.

Albert Nix
08-16-2012, 8:44 AM
Rodne do you mind sharing your source in China and the person that you would recommend contacting. It will not be long before I buy a 2.5" lense and a spare mirror for my MII. Thanks