Laser Advice Appreciated

I posted a question in the hardware forum yesterday and it's had quite a few views, but no replies, so I thought I 'd try here as maybe it's more appropriate?

I'm an FFL that is looking for a fiber laser primarily for marking NFA items we manufacture, as well as firearms. When doing a lot of searches many of the results were posts here. I've searched "firearms" and read all the threads I could find. I've also read the "ebay guinea pig" thread, and all I can find about the various lasers. From what I've learned, I think we would be well served by a 30 watt fiber laser.

Looking at the available units, it seems most are using the same, or similar equipment. I'm leaning heavily towards an ebay unit and would appreciate any recommendations on a good seller. SFX lasers has been on ebay in the past, and currently has an Amazon store. Their pricing is higher than other ebay sellers and the listed specs are identical to other, lesser priced units. It sounds like what you get with them is pretty good customer service and a 2 year warranty.

It sounds like getting different sized lenses to fit the common units is pretty easy? What would be a good size to start with? 150x150? We don't have any areas larger than 5 or 6" we need to mark.

Any advice or recommendations would be very much appreciated.

You CAN ( I didn't realize it at the time) find SFX's website and buy direct from them.. Would be cheaper due to them saving the ebay or amazon fees. They helped me when my source failed earlier this year and replaced it. So far no issues with the new source either.
MY first was from Ray Fine and I bought direct. Just watch the sellers that sell a lot of other junk items. Stay with companies that look to be assembling the laser.

I bought a 50 watt and already had a 20 watt. A 30 is fine for the NFA ( My 20 is also perfectly fine and I use it for most of the firearm marking as I have settings correct)
It takes about 10 minutes or less to set up, enter the info and engrave a firearm. If you are doing in house stuff, I would expect about a 2 to 4 minute cycle depending on how long your company's name, and city name length is with a 30 watt. I just finished a batch of p80s for a local company and cycle was 2 minutes and 15 seconds. Plus 10 to 15 seconds changing out the part. If you want to do uneconomically viable things like port slides or barrels with a fiber, then go with a 50 watt. I say this as a mill will be several times faster than a 50 watt laser when cutting through thick steel, they are, even at 50 watt and engraving machine, not a replacement for a mill. Good luck.

Thank you for a very informative reply John Lifer, I genuinely appreciate it. That was the kind of information I was looking for. I will look for SFX's direct website as well.

I would like to be able to offer custom graphics on firearms like AR's as well, and have no doubt there is a learning curve as it's been a while since I worked with Adobe Illustrator.

What size lens/work area would you suggest as a good starting point John? It sounds like changing them out isn't difficult and they are readily available?

Changing lenses is easy, though it can take a bit the first time to get them calibrated in the software (after that, it's all saved... there's a bit more to it than that, but it's easier to explain once you start using the laser). A 110 or 150 lens is a good middle of the road one-- my 110 is on my laser 80% of the time. Lots of folks use a 300 for tumblers (larger work area does mean less power, but the lens is more forgiving of curved surfaces as it has a wider "in focus" band). A 70x70 lens is about as small as I'd recommend. The work area is limited, but the laser dot is smaller, allowing for effectively higher power. A short focal distance than that (like a 50mm lens) puts your lens so close to the work piece you start to have to worry about splatter hitting the face of the lens.

Lenses are about $70 a piece for decent ones (if you buy from Asia, double that for US sources that buy from Asia and mark them up), so they are easy to add to your arsenal down the road once you find a need for them.