Form3… antialiasing ?!?

I am considering purchasing a Form3. But before, I did a test print at SolidXpert in Montreal on a Form3 printer. It is a small part intended for the realization of scale models and I must say that I am disappointed with the result! The details are good, sure, but I wonder about the smoothness of the part! Is it possible to enable “anti-aliasing” on the Form3 to make the part smoother? The piece is 55mm long!

Thank you in advance for your answers and for keeping me informed of any similar features that exist on the Form3!

Rene

What thickness did you print at?

Most of my parts when printed at 50-micron with a standard resin (white, black, grey, etc) come out visually smooth. If you run your fingernail down the part you can notice the sedimentary lines via a slight vibration. But I can’t see them without a magnifying glass.

My guess is that SolidXpert print was either done at low-res to print quickly, or perhaps the printer hasn’t been properly maintained.

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Thank you for your answer, rybu. The printing was done at 25 microns. I wanted to see how capable the printer is! The small rivets printed perfectly well as well as the structural lines! For that, it’s really great … remains the smoothing.
So it could be because the Form3 was not properly maintained !!! And as for anti-aliasing, there is this function on the printer as we find, for example, in Chitubox?

These printers require a bit more maintenance than I expected. The documentation (IMO) does not emphasize the kinds of regular maintenance owners should be doing. It’s not difficult maintenance, but given the very polished way Formlabs likes to present things, they should be a bit more up-front about regular maintenance items.

I get the impression Formlabs has a hard-core of dedicated users that know all these things, but to people new to 3d printing, if all you are going by is the Formlabs documentation, it can be a bit confusing.

Ok, cool! Thanks for these informations… always good to know!
And for antialiasing ? Does it exist on the Form3 or in the Preform app (I personally haven’t found anything similar)!

I am new to Formlabs and SLA in general, I also think Formlabs does a great job of presenting and maintaining documentation and I am currently trying to learn up front which maintenance tasks are needed for my Form 3. So to which extra tasks are you referring to? The user manual of the Form 3 has a chapter dedicated to preventive maintenance. Even though it’s off-topic here, I’m surely interested!

What do you mean exactly by “antialiasing” here? Maybe what you need are more accuracy in the export parameters of your .STLs, This is independent of the printer.

Hello hoolito,

The anti-aliasing is a software feature that helps smoothing between each print layer!
As explained here (Chitubox software): 5 Settings to Improve Your SLA/DLP/LCD 3D Print Quality : 5 Steps - Instructables

And on this page, we’re talking about the Form 3 anti-aliasing (Yellow highlight)!
But I never figured out how to activate this feature in Preform!

I have a small PhotonS and this function is supported! I find it strange not to find it in Preform.

I don’t know how the Formlabs printers would do anti-aliasing, they don’t use a pixelated light source like an LCD screen or a DLP projector.

The only way to improve stepping is to move the laser in smaller increments, which it is already doing as much as it can.
The Form2 doesn’t have noticeable stepping in the X/Y direction due to how the laser is moved around, which results in very small increments, the Form3 is a bit different in that the X position is not controlled by a galvo but instead the whole laser assembly moves side to side and doesn’t have as fine of movement.

Yes. Antialiasing is a technique for masking pixelation, so I think it applies to LCDs for example (relevant for the Photon). I really don’t understand what they are specifically referring to with the highlighted line from the Form3 webinar… sorry.

The Formlabs SLA printers don’t support anti-aliasing. The laser is on or off and doesn’t have in-between values to smooth out stepping, like LCD printers have.

The benefit of the Formlabs printers is the 25 micron resolution which can make the anti-aliasing unnecessary due to the small detail.

About the yellow highlighted text, I would have used the word ‘mixing’, not ‘anti-aliasing’ since the whole world uses that for smoothing pixels along an edge on a 2D screen. So it’s not ‘anti-aliasing’ but mixing of values, there’s a difference.

Different resins produce different surface finishes. What resin was used for this print?

Thanks Carlissimo and Randy_Cohen for you answers.

I now understand better how this type of printer works.
The small tank was printed with “Grey Resin Tough”
Maybe I would have been better with Grey Pro Resin or Great Standard…

What would you recommend to me?

For surface finish, I think Grey Pro is the best.

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Hey Everyone!

Thanks so much for contributing! Just wanted to clear up a couple of misconceptions!

The SLA printers from Formlabs don’t do AA in the traditional sense, because as it’s been mentioned, the laser isn’t really working on a “pixel” level while printing. Some fancy smoothing math does go on behind the scenes, but aliasing probably isn’t the right term. The quick and dirty answer is that most of those calculations happen before printing rather than during printing.

Additionally, it’s worth mentioning that the Formlabs machines are entirely capable of adjusting the intensity of the laser not only during a print but at any time, even within a single layer. When PreForm slices the part into layers to send the printer, it’s assigning laser intensity data to those layers at the same time based on a bunch of factors about the part, material, etc in order to achieve the best results for that particular object.

Hope that’s helpful!

For the Form1 and Form2, I would assume the galvos are being positioned with a D/A converter. So the mirrors have discrete positions. A circle is interpolated as a series of steps in the X and Y directions, which should need anti-aliasing. But if the laser stays on as the position is changed, which I suspect it does, the laser path is implicitly anti-aliased.

For the Form3, the laser only moves in the Y dimension. X is controlled by a stepper motor. This changes the way the beam paints the print. Unlike the F1 and F2 where the beam path is essentially arbitrary, the Form3 beam path has to be rasterized into discrete scan lines. The motor moves between each line and the laser is off when it does. So conceivably, the Form3 could use anti-aliasing to smooth the X Axis. But if the minimum step distance is a fraction of the beam width, it could easily do this (and, I suspect, it does).

All the Formlabs printers use a stepper motor for the Z axis. That can and does produce aliasing, which is evident in the layer lines you can sometimes see. It’s why a thinner layer height produces a smoother looking surface. Those aliased steps are smaller.

What maintenance do you do to your Form3?

Emptying, cleaning and inspecting the print trays. Filtering the resin.

Cleaning the print platforms.

Occasionally cleaning the roller holder. Sometimes I’ve had to replace it.

Occasional cleaning of the cosmetic surfaces. No matter how clean I try to keep things, invariably there is a little resin splash on the inside of the printer and on some of the surfaces.

Those are the main things. The print tray is the one that needs the most regular maintenance. The roller holder mostly just needs cleaning if your print tray starts to degrade.