It crossed my mind, but it’s just a class1 laser. You shouldn’t be able to cause any damage even with a direct shot to the eye. But for the heck of it let’s be careful.
I thought it was only class 1 because of the enclosure - see wikipedia:
Class I[edit]
Inherently safe; no possibility of eye damage. This can be either because of a low output power (in which case eye damage is impossible even after hours of exposure), or due to an enclosure preventing user access to the laser beam during normal operation, such as in CD players or laser printers.
Nope, that’s class I like Indian. The laser says class 1 like One.
Hmmm - pretty sure it’s still not what you think - see also this from http://www.npl.co.uk/publications/good-practice-online-modules/optical-radiation-safety/lasers/outline-of-laser-classifications/
You may come across equipment labelled as ‘Class 1 embedded’ – this means it is in fact a higher class of laser that is within a setting that effectively reduces its potential harm to that of a Class 1 laser. A Blu-ray player is a good example of this.
Just checked the back of my machine and it doesn’t say “embedded” - but even so, given that the original F1 was talked about as using a blu-ray laser, and the F1+ laser is now more powerful - I’m pretty sure it’s NOT safe to look down the barrel when powered.
Plus - I’ve actually partly melted cut out bits of red plastic bag when I was trying to take spot-shots.before I had my red camera filter.
2 Likes
It’s fine as long as it’s not hitting anyone’s eye directly.
It’s a good practice to not look at the hotspot on the wall / ceiling either with your naked eyes - it might not be necessary in this case, but like i’ve said - good practice.
DISCLAIMER: Despite what i’ve said - always wear laser safety goggles if you can. ALWAYS. Not because you’ll damage your eyes by opening the cover once or twice and having the laser shoot in free air, but because you’ll be sorry about that one time you forget to wear them while playing with some laser somewhere and it rolling on the table and shooting straight into your eye or reflecting of an inconveniently placed shiny metal coffee cup. It’s not because wearing the goggles once or twice will damage your eyes. It’s because it NEEDS TO BECOME A HABIT.
1 Like
Considering i can see specks in the square, i’d say you’re looking at the leftover back-scatter from the paper (there’s still plenty of laser hitting the area around the cutout, it would seem), reflected off the main mirror. The specks are likely dirt on the mirror.
Try folding the paper slightly and peek inside from the side - see if the insides of the printer are lit bright blue.
By the way, the fact you can see the shadow of the Z axis slide leads me to believe the ambient lighting is way brighter compared to the laser and the square projected on the paper, in comparison to the previous photo.
Which leads me to believe cutting out the hole reduced the amount of backscatter significantly.
I might be totally wrong, though, this is just my take on what i’m seeing in the photos 
Nice pictures @SachaGloor, good to see that the paper template is working 
I’m going to run the rook test today at 0.25mm layer height in clear v1, with no supports.
The shadow of the Z axis is actually coming from the reflection of the laser off my ceiling! All the lights in the room were turned off for the pictures.
Hi
I have tried to print the rock in black at 0.25mm without supoprts. First time i print with the black resin. Two fails in a row. See this picture:
But it looks perfect at 0.10mm:
I did not tested it with clear resin or at 0.05mm. Or even with supports. A lot of combinations that takes printing time.
Sacha
Wow @SachaGloor that is worse than I expected. Mine prints in it’s entirety just has a rough side. Did you print the rook I gave the link to or the one off of thingiverse? Did both of yours fail the same way with a big expanding hole in the center? Have you attempted to adjust your platform height so things printed directly to the bed print at the correct thickness?
I’ve used the one found from thingverse. Both failed the same way @0,25mm. I did not adjust my platform. Because i did not saw any problems before.
Will try to print the model you gave me the link.
Sacha
This all brings me back to @Monger_Designs comment about wanting a more thorough test print for our use and more importantly FormLabs product testing. How do people feel about making that a new thread? It does not cross me as a simple problem.
here are my laser spot tests:
laserspot-test-19122014.jpg - the test before I had to send my printer back for repair
And here are the laser spot test of the repaired printer. (Arrived yesterday evening):
laserspottest-13012015-1-4sec_5-6f.jpg - test with steve Johnstones pdf-file - exposure: manuel 1/4 sec f: 5.6
laserspottest-13012015-magenta.jpg - test with an old resin tank (silicon layer removed) and an old agfa magenta filter
Klaus
a
@EvanFoss he printed the wrong one that is why it failed. However I am working on some better prints just don’t have much time at the moment.
@SachaGloor yeah that is why I made ky own version with the hole in the bottom filled in. Try the one from my post earlier and it should print fine at 0.025. Also if you have trouble getting it off the platform just pull it off. Pulling at an angle. It’s strong enough to take it.
Couple of thoughts on this…
The carrot flair looks like there is an alignment issue with the laser tube, am I correct on this? If so then I would think the laser should be replaced if it poses a problem. Are there other suppliers for this laser, maybe someone that manufactures them in Europe or the USA rather than if it is made in China? Wondering if there is a compatible laser from someone else that could be just plopped in.
Many show a glow around the dot itself when projected on paper, I think that could be the paper itself diffusing the beam.
Restricting the laser dot as Josh did seems like tricky business, changing the spot size seams so critical that it could leave a pattern on flat surfaces if restricted too much and if not enough you may have an over exposure where the beam overlaps. I have this pattern if I don’t have my focal point dead on and have the ppm to match the dot size when engraving large areas. Even cutting can cause saw marks if not set just right on my co2. It’s not like we have fine controls on the pulse rate, speed and intensity on this.
Someone else suggested positive airflow, I think this could be a nice little aftermarket item that if designed correctly could be put inside the machines, seems like there is enough room to put a small filtered fan inside to keep dust from resting. Dust seems to be the biggest problem outside of poorly mixed resin.
Again I do have a flair but it doesn’t seem to be hurting anything, recently printed out my makers mark to make a mold from and the total height of the smallest letter was .027" and perfectly legible. With a min feature size of about half of that this seems really good.
I even have a light haze on the mirror where you can see a square background. So the oddities of the laser spot and shape don’t seem that critical in most cases. Of course some have outrageously flawed beams that indicate something is broken.
And yes I do use Silly Putty to test impressions on parts before blasting through a bunch of mold material. Helps when touching up parts to see if there are flaws that may show up after painting etc. too.
Considerng @JoshK’s earlier post about the size of a 300um point and the underexposed shots taken by @Christopher_Eyhorn, I don’t think the 300um laser point is hitting the barrel. I think the laser has a lot of spread at different intensities and some of this spread is hitting the barrel. However more exploration will make this clearer.
Have you printed my rook at 0.025um directly to the bed yet? If so how did it come out? Anyway fine details and tiny minimum feature size will not in a lot of cases exacerbate flare problems. So your stamp print is not likely a very good test for flare problems.
Hi all,
I managed to print whack23’s Rook Sample on the 2nd attempt @ 0.025mm, in clear v1 resin.
To cut a long story short, there are loads of defects on the rear, some on the front, but the side were perfect. The part exhibits the exact same issued as in my previous posts.
I also got my wife, Sharon, to take some macro photos off the Tall Thin Calibration test peice.
For a more further details please see the video I’ve just uploaded -
Rear Face of the Rook
Rear Face of the Rook - Lower detail
Tall Thin Calibration test
This also seems mostly unlikely as @KevinHolmes blob test to show the flare exhibits the same glow around the dot itself, and no paper is involved at all with his method. It’s possible the resin diffuses the beam about the same way and amount, but that seems unlikely.
1 Like