Form1+ laser flare issues illustrated - pics and video

Ok so in reference to the quality of the print varying between the hinge side and peel side I haven’t verified it my self but now that multiple people have all verified it I assume even if it is not true on my printer there is a commonality between all the machines that do exhibit it. I’ve also been trying to make since of it. So previously @Monger_Designs suggested it was due to different distances and focus due to @KevinHolmes findings about the laser not being collimated. However the moment he suggested it I thought to myself that doesn’t make sense, the hinge side and peel side should actually be equidistant since the Y galvo and the X galvo are centered in the optic path, as you can see in this picture.

[Laser at right, Y galvo coming from top, X galvo coming from left, small mirror on bottom]

So I thought about it a little more, and realized that basically the severity of the artifacts is not a function of the distance from the laser, but instead a function of the Y coordinate (Y being the top galvo which handles left to right position). This led me to think that the variation is probably due to something involving the X galvo, as it is more likely to exhibit some problem or flaw that results in a seemingly roughly linear change in severity along the Y axis than either the mirrors, or the tray, or the Y galvo. In terms of the X galvo the hinge side is the glue side, while the peel side is the free side.

I also considered in this what @Ante_Vukorepa mentioned about point compression due to angle of incidence, however it seemed unlikely to be the culprit as most peoples flare seems to run parallel to the Y axis.

@RocusHalbasch Ok I am clearly wrong about there being levels in the support team. I think you are over thinking the optics issue here. If you are correct and there is something special in the geometry the laser beam is going through then why did @JoshK’s “laser choke” work?

I can not comment on the effectiveness of the support team as I have not called on them yet. I will later. Perhaps with more unhappy users they will cave and accept the reality of a design flaw in the optics of the printer.

Have you given any thought to my idea of making a print they can’t rotate into working around the print flaw?

@RocusHalbasch - I never suggested that laser spot focus might be responsible for the issues. The reason I mentioned and documented the nature of the F1 laser focus - was to show that a simple aperture placed close to the laser outlet would not be sufficient to prevent the flare - or at least not for my laser.

The problem is - and always has been, flare. - as I proved in the OP. My focus has been, and remains, figuring out a way to filter off the flare. But my research showed me that a simple aperture close to the laser as put forward by @JoshK would be extremely unlikely work in my laser - and hence was not a repeatable approach - whatever success he had.

As to why the hinge side is typically the worst - I haven’t thought about it much - maybe @Ante_Vukorepa has it, but I didn’t immediately understand his point and to be honest - at this point I’m not interested. If we can block the flare, then it shouldn’t matter.

@RocusHalbasch You could also try asking them to look at this thread on the forum specifically @KevinHolmes posts at the start of this thread.

Have you given any thought to way I said about a model that would show printer failure irrespective of orientation?

@EvanFoss and @KevinHolmes I think you are reading more into what I was saying than was intended. I am still very strongly of the opinion flare is what is causing the over-curing, so I still believe eliminating the flare with a choke or collimating lens or other method resulting in a sufficiently powerful point without the flare, would and will fix the problem. I just think if there is indeed a common trait that flare problems are worse on the hinge side of the print area than on the peel side clearly “something else” is having an effect on how much effect the flare has. I do not however make any assumption that if you change or fix this “something else” you would be able to fix the problem without also fixing the flare. I was also not saying there was something special in the geometry the laser beam is going through that caused the problems we are seeing as opposed to flare. I was also not saying @KevinHolmes suggested that the non-collimated beam and focus caused the problems we are seeing as opposed to flare. I was simply trying to figure out what the “something else” that was clearly having what appears to be a roughly linear effect on the severity of the flare problem across the build area was.

When I said “the severity of the artifacts is not a function of the distance from the laser, but instead a function of the Y coordinate” what I meant is simply how badly a given print comes out depends on how close to the hinge it is. That is a really strange property, and I just wanted to account for why that could be.

When I mentioned @Monger_Designs suggestion, I was saying he thought that focus combined with the increased distance from the laser due to the path were the reason the effects of the flare were worse toward the hinge side of the build are than on the peel side.

So to try and explain it more clearly, since some systems seem to exhibit the common trait of printing worse on the hinge side of the print area than on the peel side suggests that something is having an effect on the severity of the flare’s effects with a clear property of handedness. If you follow the optic path on the left and on the right they are the same up until the Y galvo. Once you get past the Y galvo they are basically perfect mirrors of each other where any flaw is just as likely to occur on the left as it is on the right, except for the the X galvo being connected on the left hand side. Since that is the one thing that exhibits a clear handedness, it seems like a likely culprit to account for the variation in the severity of the flare’s effects.

I redid the earlier test just to see that the phenomion really does get worse when you set the printer to the smallest layer thickness. The one on the right is from the hinge side and the left is from the peel side. Please note that I did this with the freshly filtered resin just to be sure this is not junk accumulating in the tank.

The same two parts only rotated 90 degrees.

I have asked them read this thread specifically, you can see how much that helped their understanding. As for a different model that would show printer failure irrespective of orientation, I have thought about it, but I’m not sure it would help. I think the problem here is that they do not want to think of this in terms of why a print prints incorrectly, or how the printer works, or whether it is behaving correctly. Instead of looking for the root cause and evaluating if that could be a problem with the printer they just try to find some way to work around whatever the single problem they currently face is. They seem to usually do this through trying various all purpose fix-up techniques, like add supports, or rotate the object, till something works, without ever really analyzing the problem. I think the result of such a model would likely be something like them telling me to print the part in multiple pieces and assemble them with resin and a laser pointer, or some other single case workaround. The real problem is they seem to think this is acceptable, and that a printer that can be made to produce a decent print with enough workarounds for the assorted manufacturing and design flaws the printer has is a perfectly good one.

@EvanFoss so what is the resolution of the top image and what is the resolution of the bottom image?

Oh those are the same part just rotated to show how bad it is. Probably +100 posts ago I did the same prints at 0.1mm instead of 0.025mm just to see if I had this problem. I wanted to repeat the experiment at the finer resolution to to satisfy in my own mind that the issue is flare related.

@EvanFoss that was post #176. And they do look way worse at 25um. So like I stated earlier I still think it’s flare, but I don’t see how the fact that the artifacts are worse at lower resolutions confirms it. Could you explain?

@KevinHolmes Do you also have a support ticket in and if so how is it going?

@RocusHalbasch We all payed for printers that could print the full volume stated in the printer specification. If you show that a print irrespective of orientation fails with in that volume I think they would have to take our issue more seriously. I know that it is frustrating but it is the way of the world.

@RocusHalbasch At 25um the laser is retracing the same area of the tank more so the flare is applying more energy and as the experiment showed causes more resin to cure.

@Sam_Jacoby I realize it is impossible to prove a negative but if the problems @RocusHalbasch, @KevinHolmes and I are all having are not caused by flair then I have to ask what does FormLabs R&D think causes them?

@EvanFoss - no ticket, initially I thought it might be an easy problem to solve, and that it would simpler than going through support for a replacement - which I guessed going by other comments from @RocusHalbasch, @JoshK, and @Monger_Designs would be a tortuous process - and that even in the event of a replacement there would no guarantee of the replacement being an improvement.

However - it’s actually proving very difficult, initially I assumed the beam was collimated, and it that was a simple mechanical aperture problem to remove flare - as I show in post 225 however - that’s not the case. So it requires at least one more lens - and I knew nothing about optics, the learning curve is steep. I may end up trying for a replacement machine in the end. @SachaGloor’s results prove that some lasers are worse than others - case in point, mine.

But I’m still working on a solution for now.

@EvanFoss what we bought was an SLA printer with a given print volume, the specs don’t claim any object that can fit in that volume is printable. All 3D printing techniques have limitations, SLA included. In order to print some objects correctly you do need to make concessions and do workarounds. Supports are an example of a necessary workaround for some objects to be printed correctly on an SLA printer. In order for the model to actually force them to “take our issue more seriously” we would have to make a model that can’t be printed correctly on the Form1+ with reasonable workarounds to account for limitations of the SLA process, that should be printable with reasonable workarounds using the SLA process. Or we would have to demonstrate that any workarounds required to print the model correctly on the Form1+ should not reasonably be expected to be required of a device using a variation of the SLA process. I really don’t think it would add much pressure on them.

@RocusHalbasch The specification is there for max print volume, min feature size and resolution. If there added limitations they had to be stated. While I have a lot of sympathy for FormLabs they gave hard numbers and I expect them to be met. I understand that I can not of course print a solid block occupying the full print volume but other than that unstated limitation I see no room for compromise here.

@EvanFoss should it be able to print a sphere without supports?

@RocusHalbasch Obviously the supports are an exception and so are the issues with how much surface area you can peel of the resin tank in one go.

Thanks for everything (and to everyone) who’s been posted here! This is probably our longest thread and one of the most interest (and informative).

I wanted to toss in a few points into the mix — as well as close this thread off (see below for reasoning). It and all of the attached files will remain available.

To the concerns of those who’re worried that we’re not reading this thread, I assure you, we are. Probably too much :D. We’ve got other work to do! Not just myself, but folks from our engineering team, R&D, etc. We’re listening.

For those just visiting this thread, concerned about their own printer performance — please contact our support team. While there are genuine concerns being raised here, in all likelihood, the printing issues you may be seeing can be solved elsewhere.

@RocusHalbasch — our entire support team works extremely hard to make sure you, and everyone else, are successful. We can always improve, undoubtedly, but I know it hurts them (and everyone), to be so singled out and I’d appreciate it if we could keep it to a minimum here, in our forums at least. I know that they’re discussing the issues you’ve raised quite a bit. I know that you’re frustrated, but in the interest in keeping things cool, it’s a small thing to ask. You’ve been here for a long time — I’m not trying to dampen your voice, just asking you to consider the feelings of others. They’re trying hard. I promise you, and there may be other ways to let your feelings be known.

@EvanFoss — I don’t think anyone is dismissing anything here out of hand, here. As @CraigBroady notes in #41, these are some of the basic constraints that we operate with on the engineering & design side of things.

The artifacts you’re seeing in the various test prints are are a byproduct of some of challenges that we face, and we do our best to design around them.

To that end, I think it’s worth explaining a little bit about how we approach what we do. We’re working to build and support a remarkably powerful machine and make it available at a price point that allows for businesses of all kinds to get into 3D printing. I think we do it well, but it does mean we need to focus on what we do best. Do all prints come out uniformly spectacular at every orientation? Absolutely not. Does any resolution work for any model? Nope.

What our team focuses on is getting successful prints— that is, can you print your part successfully for your needs? To do so, we look at all of the tools are our disposal — orientation (and auto-orientation), layer height, build platform position, etc. The fantastic work done here highlights some of the challenges that we tackle—but doesn’t necessarily change that focus. I understand that’s frustrating for those of you looking for the perfect machine for all situations—and believe me—we want that too and we’re working towards it.

The group here are some of the smartest folks I’ve come across, and you guys have a deep knowledge of the machine (and how to make it better). I hope the above makes sense to you.
And of course, if you’re just not getting usable parts from your machine, I do encourage you to open up a ticket, and we’ll do the best that we can to get things fixed up.

I’m going to close this thread. It’s grown difficult to work with and covers many topics. I encourage you guys to keep the conversation going in more focused threads. The optics stuff has been fascinating. We’ve been discussing adding an ‘R&D’ section or something similar in the forums, which might be a better home for these discussions. Let me know if you’d like to see that!