A laser flare solution and initial results

Wow Vince, can’t believe how many machines you ran into that were junk. I would love to know how many machines out there good vs. bad.

To illustrate what I was talking about with resin being mixed, part orientation and possible/probably lens flair effect see attached. (note that one of the junk parts I was testing some coating on after the fact so ignore the shiny gold paint).
First 2 pictures illustrate the part printed with supports at the proper angle where the back became blobs but the peel side was much better but not perfect. The Third pic is the same part printed flat where the details are absolutely clean. There was a small chip I repaired on the edge but not sure what caused that, possible blowout from resin. No holes inside the model.
Fourth model is a part I printed dozens of and only a couple had some small flaws, again on the edge but the majority printed perfectly and across the entire tanks surface.

Keep in mind these were printed on a 3rd party resin and I was told that the bad part failed due to blockers settling too quickly causing the support side to cure inconsistently. I believe that the strange waves are caused by the uneven blocker in the resin in conjunction with the laser’s flare. I say that because the compressed side is better than the side that has lose resin that is refracting unwanted light throughout the surface. I also say this because flat objects print just about perfectly and very consistently. To say it is the laser alone I would have a 0 success rate, small details would be distorted or exposure would be skewed and plugged on one direction always.

I also wonder how much temperature affects the resin, Maybe it is stored in volume in a poor location or the shipping monkeys are killing the product with their poor shipping with extreme temperature fluctuation.

With that in mind and there seemingly no better lasers to replace the ones in our machines then maybe a better resin formulation would do the trick. One that would keep the blockers in place longer (finer blocker pigment) along with a thinner less viscous resin that requires less peel force).

Maybe we need fine tuning ability for the laser’s speed, intensity (if there is such an adjustment) to compensate for the variables on the individual machines.

Down the road, maybe their next generation machine, I would highly suggest to get the laser diodes without build in lenses and do all the collimating and focusing outside the diode. This would allow for fine tuning and much easier laser replacement. To have the lens and collimating done in a consumable part of the machine to me seems to be a bad idea and leaves them at the mercy of the manufacturer (probably over seas cheap import).

@KenCitron why on earth do you think that just because your problem is likely not the laser that other people don’t have problems with their lasers. I mean just because I can walk fine doesn’t mean I can be pretty sure all those people in wheel chairs can too.

As for your prints I agree they show no sign of laser problems. The one blobby one vaguely looks similar to laser problems but only vaguely. However it seems the problem there was your choice to use an incompatible third party resin. Most of the users claiming laser problems did not make that same unfortunate choice so that does not seem to apply to them at all. Your other two prints do not show the problems other users have had so it seems the information you have presented in an attempt to demonstrate that most of the laser problems are not laser problems is just compleatly unrelated. Please if your going to accuse a group of other forum users of being incorrect and that their problems are user error, first attempt to gather some related evidence to back your supposition. In a case like this in particular it might be good to look at the body of evidence they hold and have a counter example or explanation for most of the major points.

Also for your last two prints the chips out of the outside edge are just simple blowouts. You say there are no holes inside the model. I think you misunderstand how that works as I can see the holes in your pics. During the print process the surface of the PDMS acts as a wall. So if you have a situation where your printed part with the PDMS as an additional wall results is a closed off hole you risk blowout. Your prints are almost a textbook case of one easy way this can happen.

In reference to your statements there are no better lasers available. For people that do have laser problems that is not true. If I had your laser I would have a better one as we have already established yours is fine, and I know mine is defective. Also being as this particular laser is only available from Formlabs all that is necessary for a better one overall to be available is for them to have it made just like they had this kind made.

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Did you read the post?
My point of posting the pictures of the part with bobbed back was to show a combination of resin staying mixed and flare. This is a more exaggerated result but similar to what others showed.

If Formlabs is having these lasers then the manufacturer should be able to correct and replace the faulty lasers. If they are off the shelf item then maybe Formlabs needs to find a better manufacturer and replace the faulty lasers.

Yes I did. First you said:

Which clearly suggested that for many who think they have laser problems you believe the problem is not the laser, and it is instead user error. Then in the next post you wrote:

Referring back to your previous post, which suggested the problem was actually user error. However you did oddly mention flare as a possible problem contrary to your previous statement. You then note the following later in the post:

This seems to suggest you believe flare may make some things print worse when the user does something wrong but that, the laser alone will not cause problems. This is where I completely disagree. I don’t think you have severe flare problems from these pics, and therefore I think they are not relevant to a discussion about users who do.

I don’t have multiple machines here to compare how bad my laser is and if it is or is not within what ever QC tolerance that Formlabs has. IMO any flare is bad.

What I do know is I have similar print problems even with the Formlabs resin as others exhibited.

What I do know is for me and my situation I have been able to alleviate some of the problems with the way I handle the resin by shaking the hell out of it prior to use and not storing it in the tank and filtering it when draining the tank.

The blobbing as I had said happens as the blockers don’t do their job and allow light to pass through the new layer and start to expose raw resin that is on the build platform side. This problem is worse as the flair will expose more of that area over a number of layers which causes waves as the exposures stack up.

Without the flare, the parts side facing the build platform would produce a rough surface and less blobs with the same resin.

I have suspect that the resin is getting damaged from being exposed to extreme temperatures. It might be as simple as putting the resin in freezing temperatures is causing the photo polymers to break down and the pigments to clump or separate from what ever suspends them. This is something that should also be confirmed. Maybe start a new thread.

Is Formlabs going to address the flare issue? Even offer replacement lasers?

If this were true, it would be impossible to ship any resin during the winter.

Pigments settle. It’s a natural and normal occurrence - it depends on viscosity of the medium and size of the particles, there’s all there is to it. That’s why you shake and/or stir the resin before printing. Photo-activators typically don’t care about the temperature - it’s the resin that’s influenced by it.

I vaguely remember there being a thread with photos of various people’s spiral cylinder test prints.
I can’t seem to find it no matter what i search for.

Am i going crazy / misremembering or is it gone?

search for ‘Rook’, as it’s a custom chess piece.

That’s not what i’m talking about.
I’m talking about the test object @RocusHalbasch designed and its originating thread.

Doh! nevermind…

Ah! Finally found it.
If anyone else is looking for it: Form1+ laser flare issues illustrated - pics and video

@KevinHolmes tall cross piece tests are in the same thread (alongside all the spot photos - weird, i thought the test print shots were a separate thread).

Previously printed the double helix cylinder test in clear, at 100um and it was almost perfect (a few mottled spots here and there on one side). Now finally tried it with black at 50um and it’s evident the flare on my Form1+ has the same effect as everyone else’s here, except to a slightly lesser extent. The “bad” side starts at 00:10 mark.

Did it as a video, as it’s easier to notice the helical nature of the mottling on the surface than from the photos.
You can see the “ridge” on the “clean” side too.

What i’m finding more worrying is at the very end of the video - the two flats where the helices end are pitted. After the print, those were semi-cured, instead of fully cured. I was very careful not to touch them - the end result in the video is purely due to insufficient curing and uncured material being washed out of them by the IPA.

In case anyone was curious, this is my spot shot:

I’ve compressed the dynamic range a bit so the actual brightness of the center compared to flare is a little closer to what i’m seeing by naked eye. Not very scientific (i wasn’t keeping track of exposures), and shot without a tripod - these were just quick snapshots while i had the vat off the printer.

Your spot looks like ‘Burning Man’ :smile:

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@Ante_Vukorepa could you do a full panel for the DSLR thread.

I will, as soon as i find some free time to dig out my tripod.

here’s my favorite flair shot

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We need to talk about your flair.

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