Bad prints out of brand New Form 3


I don’t think there’s anyone with any experience doing small detailed prints with any other SLA printer, including the Form 2, who isn’t disappointed and kind of regretting buying a From 3. It’s especially rough for those of us who got rid of a From 2, and spent thousands of dollars for a downgrade. I don’t know what to tell you. I’ve had a Form 2 since they came out, and before this, had nothing but good things to say about Formlabs. They are burning through that goodwill as this goes on though.

The only tip I can give you, is I’ve been able to get somewhat usable prints, as long as I design around the knowledge that I’m going to have a good side, and an unusably bad side, and carefully orient my part accordingly. That said, I will still end up with details softer than my old Form 2.


That doesn’t sound optimistic. :frowning:


I assume this forum is monitored by Formlabs, so would be good to get some ‘official’ response to all this.

I’m currently engaged with support trying to resolve, and my experience to date mirrors that of others. It’s a process that needs to be gone through so that either the problem is solved (best outcome, but unlikely given the experience here) or unresolved (in which case I’ll return my printer).


Yes that is the frustrating part about this whole thing. I have seen any number of threads that got an “official” response from Formlabs… but not this one. And this is a HUGE problem, and my thread blew up WAY MORE than I expected, yet not once has there been an official Formlabs person responding here. Very frustrating.


8,500 views on this thread - I guess you’d say that was a reasonable level of interest.

Presumably some of those views are from prospective purchasers who will be discouraged (wishing I’d been one of those, but I only engaged here AFTER purchase).

It’s not like the thread is entirely negative - there have been some ideas as to cause and possible resolution. Issues are specific, documented and reproducible (though not entirely consistent). So lack of response on this reflects in the worst way on the company and its products.


Correct, I agree. When I was speaking with support directly they mentioned that they have seen the thread and they seem to be monitoring it. The support contact specifically mentioned the “shield” method of nearly eliminating the problem. That interested me a lot, but obviously it is not a practical form of resolution for this problem. If anything I would think it was more helpful in identifying the cause rather than serving as an actual solution.

But as you said, and as I have been saying, and as many people are now seeing… this is not a minor issue. The reproducability and widespread reports of the SAME PROBLEM but amongst different users and different models implies there is a serious and inherent flaw in the hardware and/or software that appears to have no clear cut or timely resolution. And I am utterly dumbfounded that this could get through testing without being noticed. Just another thing to show how rushed the rollout truly was.


I’m not sure you are right here. I’ve had two Form3s now and looking back through past prints, it seems the first way very much better than the second. The second has some of the surface artefacts that have been shown here and was not able to print fine slots that were no problem on the first.

So I’m coming to the conclusion that the problems lie at a machine/calibration level rather than a systems level.


I have had 2 form3 now and both have exactly the same issues and we have also seen on this very thread people passing files around and seeing the same defects when they print the shared file so I doubt this is a machine/calibration issue.if it is then there is a serious issue with calibration because it is affecting many mahcines.Secondly I have had correspondence with Formlabs where they have admitted this is an issue that they currently dont have a fix for.




So given that we seem to be on our own here:

The ‘resin flow’ theory seems like a good one to start with. Formlabs suggested it and Donnie’s shield experiments seem to support the idea. By the way, not only do the shields look like they avoid the wavy artifacts, but the print also looks sharper. So how do you stop the resin moving around? There is obviously a gross driver of flow early in the print due to the immersion of the bed with each layer. But there is also an ongoing (and probably inconsistent) influence due to the movement of the print unit against the flexible tank base.

  1. Donnie shields. Can certainly test to see how well these work under a range of conditions, but definitely a cost in resin and print time. I don’t see them as a practical fix in most circumstances, but useful in exploring the problem.

  2. Allow the tank to equilibrate before firing the laser. Not sure how practical this is as I’m not familiar enough with the exact sequence of events. I’m guessing print times would REALLY suffer. However Formlabs could certainly do this under test conditions to test the principle (and maybe they have). Sidebar - Resin movement is a stated issue on the Solus, they have a delay variable prior to layer exposure, adjustable to cope with differing resin viscosity and generally around 2s. Not so simple in the Form3, but does support the idea that this may be the problem.

  3. Lower the resin level in the tank. Movement is driven by head generated mechanically. A film of viscous resin would be less susceptible I think. Is it possible to fool the float sensor? This would make Donnie shields more viable too.

  4. Slow the x speed of the print unit. If the print unit moves more slowly presumably less impact on resin flow (and increased print time).

  5. Reduce the distance the print unit moves the film upwards. This would presumably impact the low peel force feature - but frankly that’s not very useful if prints are soft and artifact ridden.

Any other ideas?

Not a lot here that users can do here other than play with Donnie shields and maybe trick the float sensor. It may be possible to shim up the tank to test #5. Either of the latter will probably invalidate warranty - which I’m not willing to do at this stage.


Has anyone tested whether these artifacts exist if they turn the fan off, or redirect the airflow? Not sure if that is actually the problem though since the artifacts don’t happen everywhere…but seems like an easy thing to try.


A glimmer of optimism here…

I did a print along the lines proposed by @donnie. Basically lifted the model up higher from the rafts and arranged two donnie shields to preserve it’s modesty.

The resultant print isn’t perfect but I do feel it is a bit sharper and it is usable, the ripple artifacts being quite minor.

I’m not getting too excited, but I’ll report back once I have some pics and maybe another run.


So here’s the set up.

Two shields each 0.5mm thick approximately the same height as the model. Lifted the model higher than default on the supports. 0.3mm supports at more or less default settings.

Obviously this takes longer and uses more resin than simply printing the model on default settings.


I want to update this as there’s nothing worse than threads that stop without any closure.

Formlab’s tech staff have confirmed that my Form 3 is working to the standard they expect. They acknowledge the detail resolution is not up to that of the Form 2, and that the issues reported here are real. That’s a big deal for what I’m trying to do. Good on them for being up front, though that doesn’t change the facts.

So to anyone reading this who is considering a Form 3 purchase, I’d say make sure you get a sample model first and confirm that it meets your needs. I expect that over time results will improve. Doubtless Formlabs are working on it, but they are not offering imminent solutions to the problems described in this thread.


Yep. You’ve simply found out what many of us already have, both through this thread and our own conversations with support. It’s simply unacceptable to me that they state it’s working to the standard they expect… while acknowledging the issue with print quality is a real thing they’re working on but with absolutely no timetable on a resolution whatsoever.

Although the shield scenario is interesting it is in no way practical nor acceptable to have to do it. It not only uses excess resin, but it increases print times while putting excess wear on the tank.

My warning to potential Form 3 buyers is to absolutely stay away if your main need is small, accurate, detailed parts. They simply will not be acceptable at this point.

Sharpness of print from WaxCastable resin

quick questions to the experts :slight_smile: with his issue-

as we know that printer is capable in printing smooth surfaces (I see the same issues you are all reporting on) doesn’t it reinforce the idea that its an issue with a sequence of events that are happening in different stages of the print, and issues with Preform creating support for the model? if there was a flow with the mechanism itself we would not be able to get smooth surfaces at all…
or am I completely wrong here…

New to Form 3 and new to this issue


Not an expert by any means. I cant really fathom what the problem is.I printed a large figure with dental model resin at 50 microns and it is spectacular.I try to print a simple box with clear resin at 100 microns and it looks awful.I printed a large figure in clear rein at 100 microns and the surface is very smooth.Who really knows


I understand the theory at play here, and why people come to this conclusion, but I really don’t think this is a flow issue.

First of all, the space between the build platform and the tank membrane is very small, and I don’t think there is much flow there.

Secondly, it seems pretty clear to me that this is something happening after the layers in question are initially cured by the laser, as the tank-facing surfaces, which have nothing below them, are clean and smooth.

I really think the issue here is one of light control and over-curing, not one of the movement of resin. My theory is that the laser is scattering, and non-coherent light is refracting and setting up interference patterns, which is the ripples you see in the part. This scattering would also explain why the detail isn’t as sharp as the Form 2, with a clear optical path, as opposed to a translucent-bottomed tank.

Under this theory, I’m not sure why the “shield method” would improve the quality of the print, except maybe that the adhesion of the tank membrane to the shields would keep the tank bottom flatter, causing less refraction and diffusion, but that’s just a guess.


I agree that this is more likely to be a problem with light control and over curing. But I note that if auto-orient is used Preform seems to orientate most pieces with one face parallel to the build platform, and not at the odd angles that we have become used to using.


Giving second thoughts to buying a FL3.
Maybe I’ll hold on to my FL2 for a bit longer.