Sealed optical path?


#1

The Tech Specs say:

“Enclosed optical path with cleanable and replaceable windows protects the laser optics to avoid cleaning, replacement, or realignment”

That’s a bit non-sensical how does cleanable and replaceable avoid cleaning and replacement?

I originally imagined that enclosed optical path meant that the entire travel of the beam would be sealed up until the final focusing lens. But now I’m gathering that only the mirrors will be enclosed, which solves nothing really. Sealed path and sealed optics are very different situations. Instead of cleaning and replacing mirrors, users will have to constantly be cleaning and replacing windows instead. This saves no time or effort at all. Of course replacing windows avoids the effort of realigning mirrors after a swap, but mirror replacement is a very rare event. Why can’t you just put bellows on it and call it a day? CNC machines do this all the time to protect the linear motion components, should work fine for protecting the optics.


#2

Optics and bearings are vastly different in terms of tolerance to buildup.

Lenses and Mirrors are vastly different in terms of cleaning requirements, and positioning requirements.

There is no way to fully enclose the optical path, unless you have some kind of telescoping connection between mirrors, because the gantry has to move along the X and Y axis. So you would need something which can remain perfectly rigid (absolutely zero drooping, or optical path gets blocked) across 20 inches, and will collapse down to a few mm. Rigid requirement means thick material, collapsed length means thin segments. Combine those together and you will have an insane radius for your outer segment. This will also be heavy, which will mean you need stronger motors, and likely move far slower. And it is more moving parts that can fail. And if you ALSO want it to be air-tight, that adds even more bulk (higher weight, more radius).

If you want to have air streams at every mirror, then you need to have hoses running out to ever mirror, and reel systems to keep those hoses from bunching up under the laser and on your cut target. These are also going to be blowing away from the mirrors, in two directions. And since they are blowing within the enclosure, some blowback will happen, so you have to ensure that it is 100% dust free, because high pressure streams of dust will scratch mirrors, forcing replacement to be needed. And of course having two hoses of air, and two nozzles, once again means more bulk, so slower movement, and possible stronger motors. And whenever you do still wind up needing to replace mirrors, you will have a much harder time taking apart the case the mirror is in, due to the hoses/nozzles. And you will have to keep the entire assembly completely dirt free throughout the cleaning process to ensure you don’t scratch your new (or newly cleaned at least) mirror the instant you turn the system back on.

Lenses on the openings of cases which enclose the mirrors is the most elegant solution, and it does save a considerably amount of work and technical precision for the user.


#3

Windows might be the most elegant solution but doesn’t save any work. Windows will require the same amount of work to clean as mirrors and will need to be cleaned on a daily/weekly basis depending on use, especially with the vent placed on the left of the cabinet pulling smoke toward the optical path. Also, mirrors are cheap. Replacing the windows and housings, however, will end up costing whatever GF decides to charge us…likely more than a simple mirror.


#4

However, windows will be far easier to clean without affecting alignment than mirrors… it doesn’t take much to mess with mirror alignment when you are reaching at an award angle to clean a surface that is at a 45 degree angle and has harness hardware around it… encapsulate all of that and give me a few pieces of glass to clean… its a pretty elegant solution with far less risk of messing it up.


#5

We clean our mirrors almost daily and have never had cleaning affect alignment. The real danger to alignment is bumping a mirror mount when you’re loading or unloading material. Also, the GF claims to self-align so there should be no worry there. The real concern is that the windows and housings are custom parts, but you can get mirrors anywhere.


#6

must be difference in machines, I have a FS hobby Gen 5 and the optics are tucked so far out of the way that cleaning them is the only time I risk bumping them… and the housing around the mirrors makes it such a pain in the ass that I have absolutely caused alignment issues to both my main laser and my red-dot… But I have never once bumped the optics moving material in or out of the machine.