[ELaser]

no, should be held in mechanically, eg a screw / collet arrangement

[bratan]

Here's what mirror looks like. Just to confirm, it's not supposed to look like that, right?
I could be wrong, but it looks like a piece of polished metal which corroded... WTF?

[itmaxx]

Uhhmmm.... that mirror doesn't look the way I guess a co2 mirror should.
This is the picture of a brand new mirror, found on the web.
Attachment 269446

I just received my 350 but still not able to put it at work nor test it. After this, first thing will be checking the mirrors...

[bratan]

I just received my 350 but still not able to put it at work nor test it. After this, first thing will be checking the mirrors...

Yeah let me know what you discover! I'm pretty sure it's corroded over time as it was probably in storage for a year or so. There was some water in the system too, that didn't help...
I was just researching about which mirror to get. There are various types (i.e. Silicone (Si), MO, etc.) some are gold plated, some are not, but I'm not sure, there's very little description... They are quite pricey about $30 per mirror. But it also looks like one can make mirror almost for free with a HDD platter . I'm going to try that, already ordered 25mm diamond tipped hole saw from Amazon. They say it's for glass, but I'm hoping it will be able to cut metal too...

BTW it's 25mm diameter mirror if anyone curious.

[bratan]

Small update. I started writing about my experience on my website. You are welcome to follow along, I'm hoping I don't procrastinate too much and keep updating it. Unboxing video is up.

[miketola]

SI mirrors is OK, dont buy cheap K9

Si Mirror:*Silicon Glass Gold coated, great reflective index, not good for anything 80 watts or over (not too hot on 60 watts either)
Mo Mirror:*​Molybdenum, very tough but the lowest reflective index, great if you miss cleaning or have a habit of dropping mirrors or if you have over 80 watt sources.
Cu Mirror:*Copper, Below gold Si for reflective index but tough and better index than Mo
K9 Mirror:*Close to worthless gold coated glass (likely from re-melted milk bottles), anything much over 35 watts and a spec of dust and they break. Designed for the "Hobby" series K40 lasers (the $500 ebay junk)

[bratan]

SI mirrors is OK, dont buy cheap K9

Si Mirror:*Silicon Glass Gold coated, great reflective index, not good for anything 80 watts or over (not too hot on 60 watts either)
Mo Mirror:*​Molybdenum, very tough but the lowest reflective index, great if you miss cleaning or have a habit of dropping mirrors or if you have over 80 watt sources.
Cu Mirror:*Copper, Below gold Si for reflective index but tough and better index than Mo
K9 Mirror:*Close to worthless gold coated glass (likely from re-melted milk bottles), anything much over 35 watts and a spec of dust and they break. Designed for the "Hobby" series K40 lasers (the $500 ebay junk)

Thanks! Great info! I ordered Si mirrors.