@Ante_Vukorepa hmm - not sure about your orientation; to me - front to back has always been the Y axis, and side to side the X axis, I thought that was pretty much a universal standard for CNC and 3D printing…
Agreed on the glossy area shown above - I also noted that it appeared solid.
As for the sealed bearings - yes of course they “shouldn’t” leak - but given it’s not dust, and the assumption that you had not removed the back from your machine until this happened? Ergo - a leak from a part in the F1 seems the most likely explanation.
The reason I’m interested is that it seems like it could be another “common” issue - going by the other post that specifically mentioned “grease” on the “small internal mirrors” and the number of times I’ve seen FL recommend checking the galvo mirrors.
You say the spot was in the very centre - does that mean you’re sure there was no trail from any edge of the mirror? ie it was a delineated spot with no path of origin?
Well - just checked in preform - and it seems I’m the one who’s turned around - far as I can tell - rotating parts in the x-axis rotates them around an axis that stretches from the front to the back of the machine. And rotating in the y spins the part around an axis that stretches from the hinge to the peel.
Is it just me again? isn’t that the other way around from how everyone else does it?
Would it be possible that the “smudge” on the mirror is the result of the laser affecting the fumes of resin inside the F1 and deposit the cured resin fume on the mirror. In that case it would make sense with a spot in the center of the mirror. I used to let the filled resin vat sit in the printer in between prints (even for weeks) but when you open the cover the smell inside the printer is very strong after so long time - now I remove the resin from the printer in-between. Have no idea of the relevance of this thought…
This actually does happen. I had a set of galvo mirrors once that appeared to have small burn marks on them where the laser hit. But it came off during cleaning. So I am sure it was airborn molecules (fumes) that had been bombarded against the mirror by the strong light beam. Apparently it is just one chemical though, because all the resin chemicals together would have cured.
It doesn’t really work that way. Laser doesn’t carry or bombard the molecules onto the mirror surface.
And resin “fumes” are mostly the evaporated photoinitiator - AFAIK, the actual monomer does not evaporate.
It might be possible for the photoinitiator to somehow end up on the mirror, but the laser actually wouldn’t have much (or any) effect on it, as it’s inihibited by oxygen.
When I search on Google for “Does light have mass?” it says:
The first point to make is that while photons (little packets of light energy) do not have mass, they do have momentum, and a change in momentum yields a force, so in actual fact light is able to physically interact with matter.Dec 26, 2013
I vote for theory number 1, and have been pretty sure of it for quite some time. Every printer I have received from Formlabs came with dust and smudges. Once cleaned the smudges didn’t return. My bet bad Quality Control and careless assembly, leads to smudges which on their own don’t cause a huge problem, so calibration and testing pass. Then during packaging due to being packaged in a dusty environment and into a dusty box while not being sealed against that dust they pick up lots of dust, I imagine this gets worse in shipping. The end result is you get the machine and open the box and unpack it, and it is already filthy inside.
If this seems harsh keep in mind it’s the nicest explanation I could come up with to explain why every printer I have received from Formlabs has arrived with all of the surfaces in the optic path being filthy. They really should look into doing something about that, or add cleaning the surfaces to the unpacking directions.
As for why people’s printers work for a while I’m guessing in a lot of cases it takes a while for the smudges to accumulate enough small particles to really mess things up.
Another vote for theory number 1. I think you’re spot on
In another thread re:quality control, the first response I got from support regarding failed prints that tracked to a filthy mirror was, “we’re very careful, have great QC”. So whatever they’re doing, it’s not catching the problem.
After some pressure, the second response was “escalated to management”.
I may send them a couple of screeds from Deming. They have good intentions, but a broken process.
Well - I suppose we have to rule out number 3 - the horizontal galvo isn’t underneath the vertical one - it’s beside it, and also the reflective surface is pointing downwards at the small mirror.
I have a question; of the others who’s printers performance degraded (ie it was fine out of the box) and who then fixed their printer by cleaning smudges/spots (not dust) off their galvo mirrors, and specifically the galvo mirrors, not the small stationary mirror -
which galvo had the spot/smudge? vertical or horizontal? or both? @JoshK? any others?
Also how about a slightly different option 1 - a transparent residue/film that gets burned into a haze by the laser over time. Maybe some kind of cleaning fluid or something left over from manufacture - either of the galvo itself in china, or during printer assembly at FL?
That’s possible too. And it was on the first mirror. Remember the second, third, and forth mirror never get hit in just one spot.
Also, since it was a refurbished printer and I found that on the first cleaning, who knows how long it had to do that. It could have had a massive amount of hours since it’s last cleaning.
@JoshK - so yours was a very well defined small spot right in the middle of the vertical galvo mirror - something around or maybe even less than 1mm square?
@Ante_Vukorepa - how big was your spot/smudge? given that it was on the second galvo - the horizontal one - if it was due to some kind of interaction of the laser with stuff on the mirror - then we’d expect it to be larger than the one @JoshK had.
Would either or both of you be able to draw a representation of your spot/smudge on this image to give us an idea of scale?
I know its not the greatest shot in the world but I also have a spot that no matter how much i have cleaned it wont come off also the the third mirror was covered in finger prints and had lots of smudges all over it resulting in many failures I was able to clean all but this one damn spot but i have not had any further issues since taking the time and really cleaning them.
@KevinHolmes and @JoshK. As for the theory about it appearing over time, in my case I have always had smudges on the various surfaces before I have used my printers. From my second printer till my last one. The current one is still sitting in the box, unopened as I’m so disgusted with Formlabs I haven’t gotten around to opening it. So I don’t think they ship them out looking clean. It may still be true that it progressively worsens with exposure to the laser, that I can’t say as I clean them up first thing.
Sorry, i somehow completely missed this post.
Can’t be very exact, as this is from memory and after a few weeks, but here’s what it looked like to my recollection:
If i remember correctly, it was slightly displaced to one side (as depicted).
I’m now sorry i didn’t take a photo.
