Laser Flare & the effects on your prints - Part II


Interesting results for sure! Just to play devil’s advocate here, do you have to print this at 50 microns? Have you printed it at 100 yet? Have you tried printing the plate at the same orientations with supports that are less dense and evenly spaced across the surface of the part?

The Test 2 one seems like a peel issue.

It started right between the supports. That span between the central set of supports and the side ones is too long for such a thin peel profile. The supports in the middle and on the sides keep it stretched, but then the peel rips it in the middle.

Think of it like holding a piece of sticky tape stretched between your fingers, then letting the middle stick to something (your table) and pulling. That’s essentially what happens during a peel with this kind of geometry.

I never had these issues with my DIY printer, as i was solely using MakerJuice resins, which cure to a very hard and rigid (but extremely brittle) state - they’ll sooner damage the PDMS than rip like that. Formlabs resins are way more flexible and “floppy”, which i’ve come to realize while trying to print casings with very thin, straight faces the past few days. I haven’t had any rips (because i’ve been printing much smaller objects with shorter unsupported distances), but i’ve had plenty of bad surfaces and completely bent corners and edges - exactly because of the process i’ve described.

Hi @Aaron_Silidker,

For the mold tools, yes I need to print at as fine as I get away with as it greatly helps with post finishing. This part is just a test to replicate the main cavity part surfaces that I previously had problems printing in both clear and grey. I purposelessly grouped the supports on the test piece to test my theory described at the top of the thread.

The cavity mold part shown below was printed in clear & greay resin, in a very similar orientation to Test 1.

Hi @Aaron_Silidker,

I totally agree with you. This is nearly the worse way you could orientate the model, but printed it anyway, as a comparison to the grey resin test.

Not great news.

The first part printed for the client at 0.1mm in clear v2, was a mess. It looks to have failed at about 80% and to me, it looks like the problem is getting worse.

I spent ages orientating this part to insure minimal peal force is required during the print. The wall thicknesses of the part are between 2.5mm & 3mm .

Orientation of the part.

Approximate failure point

Loads of part cured resin on the rearward face (the face perpendicular to my laser flare).

Some serious flaking running parallel with the my laser flare. This large piece was well before the print failed.

Poor rearward facing surfaces

I’m now seeing flaking on the supports again orientated parallel with my laser flare.

@Steve_Johnstone so what’s the word from FL on a replacement machine?

Couldn’t tell from those shots, was there any porosity as well as the flaking?

My machine seems to be behaving very well now with the choke in place; flaking is pretty much gone, and I run prints at one higher exposure setting to make sure I don’t get porosity. That is - I set preform to print in clear when I actually have grey in the vat, black for clear, and so on. See @JoshK’s list of resin exposure times here Resin list in order of exposure/curing?.

Not only do I have almost no flaking, but surface slime also seems much reduced and requires less IPA brush scrubbing to remove. I even suspect small holes are more accurate; I just reprinted my glasses arms and they slotted on first try, whereas previously I was having to carve out gummy surface resin from the fixture slots with a scalpel.


Just wanted to chime in here. Please don’t dismiss the condition of the resin tanks. I just changed my resin tank and got perfect prints. I noticed some clouding on the old tank, so decided to change the tank and try the same test file and it was perfect. I tried it on 50 and 25 microns and got the same perfect results.

I still have the flare on this printer (replacement), however with the new tank, it prints perfectly. Will keep track of how long it last and before I see any issues.

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There wasn’t any porosity in the print at all. Your printed glasses arms look awesome. Are they as printed or have they been sanded etc?

I don’t think fitting a choke to my laser is an option. It’s not because I don’t think it would work, it’s because I shouldn’t have to. For the same reason I haven’t tried using different material profiles.

@Monger_Designs, Thanks for the advice and to be honest I nearly broke out a new tank this morning to retry the print. I’ve decided against it as at some point I need to draw the line. This part was printed straight after printing the Test 1 clear, which printed well, apart from the poor rear facing surface. The only thing I did was strain the resin.

Here are some more pictures and observations of the part now that it’s cured -

The first 30mm of the part printed fine. I expect that this was because early on there is little part cured resin build up. Form this point the print gets significantly worse, as the part cured resin builds up over time, until it fails.

The side of the print facing the hing and running parallel with my laser flare printed fine. In the picture below please note the orientation on the flakes in the supports. They all face toward the rear of the printer, in the same direction as my laser flare. This is the same for all the affected supports.

The flakes on the supports are something new. I wonder if the changed the material setting, longer exposure perhaps, for the 0.1mm clear resin as well???

The poor rearward facing is a lot sharper and has an almost sandpapers texture.

Toward the point of failure flakes appear on the good, forward facing surface.

I think there is more then enough evidence here to prove that the printer hasn’t operated as advertised from day 1.

I’ve had 3 months of this and all the printer is doing is adding cost to my business, not value. I’ve worked really hard with FL support but seem to be getting no where. They’ve had the printer back twice for “calibration / repair” so sending it back a third time, for more of the same makes very little scene. They wont acknowledge what we in the community are referring to as laser flare, so can’t see them changing the laser. Therefore, there is something fundamentally wrong with my printer and I have asked for it to be replaced.

By replaced, I expect a new printer. Not a repaired or refurbished one, but a brand new one. I don’t at all feel confident having a second hand printer and having no idea of it’s history. At least this way I will have a good chance of getting a printer with a decent laser.

I apologize for my rant and none of this is directed at any of the support team. I expect they are just following company policy.

@Steve_Johnstone I agree you shouldn’t have to try repairing the printer yourself and that you should get a replacement - which is why I asked how it was going with FL on that front :worried: keep us posted ?

As for my print - no finishing other than a light scrubbing in the ipa bath with a baby bottle brush.

That awesome and where I would like to be.

Did they oblige? It’s crossed my mind that the circulation of refurbished printers has become the worst ones. When someone gets a replacement that has laser problems they send it back, and FormLabs sends it to the next guy. Since they don’t fix laser issues, the circulation of replacements has to have all bad lasers by now.

I only emailed them yesterday so do expect to hear back until after the weekend.

One thing I notice here: is that if you had oriented the part with what’s at the top switched to be at the bottom, you would not need any internal supports on your critical surfaces.

Hi all, just a quick update.

Formlabs support got back to me on Friday and are going to change the laser at their UK facility. The original laser will be shipped back to their headquarters for testing and investigation etc.

Obviously this is great news.

They also explained a little on the some of the difficulties they are facing with regards to determining form a customer’s laser spot test or print, whether it’s the laser that’s causing prints failures.

This I totally understand. I’ve been guilty in the past of blaming a failed print on laser flare, when it has been down to lack of experience and poor part orientation on my part.

When I first looked at my laser spot test I automatically assumed that the laser was faulty. I was expecting to see a small focused dot, instead and I saw the typical carrot shaped pattern.

I how understand this is a fairly typical laser spot test pattern for the Form1+ and doesn’t automatically suggest a problem with the laser. It’s only the very small, brightest part of the dot that cures the resin. This makes it very difficult for us or Formlabs to determine whether there is a flare or what they refer to as laser aberrations from the images we take.

To demonstrat this, reciently @KjellNilsson printed the minimum feature test and got awesome results. When you look at his laser spot image, it’s not that dissimilar to mine.

@KjellNilsson Minimum Feature Test, FL Black Resin @0.1mm Layer Height

My Minimum Feature Test, Clear V2 resin, 0.1mm Layer Heights

@KjellNilsson Laser Spot Test Image

My Laser Spot Test Image

Formlabs also explained that the porosity I’ve been experiencing has not been linked with the laser or the mirrors. It’s something they’ve been able to duplicate in their labs and are addressing it with software updates. This follows @Ante_Vukorepa theory in his post –

That sounds like excellent news @Steve_Johnstone! It’s great to hear that you’re discussing this issue in depth with the Formlabs team and we’re all learning from this.
It’s nice to see you’ve compared the minimum feature print with that of KjellNilsson’s. Especially as he has a similar laser spot as you have. However, perhaps the minimum feature test is not the print we should be comparing. Of course it’s great to see that the result of the minimum feature test is astonishing, but I think we’ve all noticed that laser flare causes much more issues with taller prints. Shouldn’t a taller print be a benchmark as well? (like the test crosses of @KevinHolmes)? This way we can definitely rule out that a laser spot like yours and KjellNilsson’s is an issue.

Yes @Alex_Vermeer, Its great news. Have you got your printer back yet?

I’ve updated my last post to include a picture of my minimum feature test. I agree that is’s not the best test if to suspect laser flare (aberrations).

I think my problem only affects a very few of us. I just wanted to point out that you can’t take it for granted that if your laser spot test looks like mine you have a laser problem.

Just FYI: I’ve updated the black resin thread (Does this look like a good bottle of Formlabs black resin?) with some shots of rooks printed in black, but at the castable setting, confirming the issues with black (at least in my case) are due to undercuring.

@Alex_Vermeer yes there are several prints that would do a better job demonstrating flare. However, any prints that we the community print with the same orientation and positioning, that result in one printer producing clean and correct results and another producing clearly incorrect results is a good indication that the problem being seen is not due to user error from positioning the part poorly, but instead due to either hardware, or materials, or handling, or environment variables. This is a huge help in the diagnosis process, and any test that may differ greatly from machine to machine is of great value. As for the minimum feature test it seems like it has high potential to come out differently on different machines for a variety of reasons.

You’re right @RocusHalbasch, we can learn from every single print! I’ll be definitely printing both the crosses as the minimum feature test when I get my printer back to check the results!

Try my helical walls as well. :smile:

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