Bad prints out of brand New Form 3

I might be wrong - but I think what you see on the bottom is not over curing- was your model parallel to the build platform? Is so- you should angle it slightly and that will prevent this situation along with adding more support

‘Over curing’ was just my interpretation of previous reviews of the potential cause for this phenomenon. Happy to be corrected on the terminology as this is a specialised area. The top surface issues are not a problem from my perspective but thank you for the reminder about angling. I think the bigger issue is that, for some prints at least - for example where there is no surface that is out of view to users, any problems of this nature with the top surface rendering will continue to affect the quality of the prints.


Here is the top surface, nearest the build platform. You can see the scalloping effect of extra curing between the support connection points.

This is due to the peel forces that “pull” on the thin first layer when it is parallel to the build surface. The support touch points do not pull because the supports are much more resistant to the peeling forces. These slowly equalize from layer to layer and the surface eventually becomes flat. Hence the “pillow button” effect.
Note that this effect is a lot more pronounced on the form 2 ( higher peel forces ) and is one of the main reasons why the Form 3 can get along with smaller touch points.
The solution is to tilt the part.


@lmlloyd - very interesting post. Similar to your experience, late last year, I had an early Form 3 that did not fully print models. It would only print the rafts. The rest of the model was just a thin wafer stuck to the bottom of the resin tank with other debris swimming about the resin. This required wafer removal and resin filtering after each of the first three prints I attempted and a call for help from Formlabs. Removing the wafers stuck to the tank damaged the tank. Formlabs quickly swapped that machine out and replaced the tank, too.

The replacement machine does not have that problem. It sounds like Formlabs was able to correct whatever was going wrong with our early machines.

New tech is high adventure.

The problem I am presently experiencing with the Form 3 printing in black V4 is that it takes a considerably greater force to remove black models from the build platform than gray V4 models. So much more force is required to remove a model from the platform that I am breaking 1 out of every 3 models trying to free them.

This has been talked about in other threads.

I’ll be contacting FL support. Hopefully there is a fix.

See my post in the other thread - but i don’t have the same adhesion issues if you sand and clean the build plate well between builds and also specifically use side cutters & the metal spatula to get parts off.

What grit?

400 or 600 grit works well for me without taking forever. Just make sure you clean it really well afterwards to remove aluminum particulates.

Even if I don’t do this - I always clean the build plate with generous amounts of IPA and several paper towels to remove residual resin. I have a pretty OCD process, but it seems to be working really well.

Very helpful information about adjusting wash times and about prepping the build plate, thank you.

Some more pictures of the latest build - Grey v4 at 25 microns:

Some tidy up still needed, as you can see with the remnants of supports around the base edges, but I am very pleased with the print.


Hi Alexander. Your orientation is wrong. I’m also making model railways (with form2) and I’ve experimented with orientation a lot to get best results. My first attempts were as your here. You should tilt locomotive to 30-45 degrees to the platform. That will result in supports on the front (or back) of the locomotive but it just cant be avoided because otherwise you get really big surfaces parallel to build plate and they get all messed up while peeling off. This way your print surface will be minimized and with that chances of layers peeling off or getting garbled are getting lower.

Grills like the ones you’ve circled won’t print good ever if every single one of them isn’t supported. Even if they print they’ll get messed up either by IPA or agitation of IPA so I advise you to make them from etched metal (I use service from If that is not an option print them as relief. I know that doesn’t look the best but it is better than this surely.

Here is how I orient my models:

Here is further proof of the improvement with Grey resin from the last PreForm software update. @larsenstephen provided a sample file that I printed before and after the update. The first photo shows the two prints, both at 25 microns:

There has been a very significant reduction in layer shifts. Closer inspection shows that the issue with the port holes is still not quite right - there is still a flattening of the top of the circular holes. The following photo is a close up of a second print at 50 microns:

Still some tweaks needed but kudos to the FormLabs team for making such a big improvement.



Whoa - that’s a huge improvement!

you should support those window headers and the top of the round opening. I Am sure those can be fixed that way. Otherwise the print looks good. It hard to tell how big it is in real life, that would be helpful.

Looks like a totally different resin. Wow, well done!

Hi Boris. Your model looks nice! You are making definitely H0… My models are smaller - 1:120. I have been making on Wanhao D7 in the past and now I am lucky starting it with F3. I oriented models on Wanhao so as you wrote - 30-35° because otherwise I nave had no chance to have a little bit acceptable quality. And now according my little experience with F3 I see an absolut hight quality nice and no roughness surfaces so that now I would let it so… An another point: If I place it under 30 -35° I have to print about 30 hours and if so(parallel to a platform) - only 18…

Thank you for the link about etched metal. I will try.

It is interesting, the printing quality can not be compared, but… the same grills printed good my old Wanhao. I will more “close” the side grills in CAD, use more supports inside and test… The grill on the roof can be printed separately.

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Thanks, Robert!

Hi Cesar,

Regarding supporting the openings, the openings are very small. The model is a ship’s superstructure in 1/350 scale. The round openings represent portholes. They are just 1 mm in diameter, too small for supports.

It should be noted that misshapen openings are occurring mostly in the vertical plane, and most noticeable in gray V4, not black V4. The model does print perfectly on a Form 2 in gray V4 with very precisely shaped openings all around. You can see that Robert’s test print compares very favorably with the Form 2-printed gray V4 model shown below.

Since the Form 3 prints this model very well in black V4 resin with excellent opening shapes, it can be sold in that material. Customers, however, prefer gray for easier painting.

Robert’s test print indicates that the Form 3 update has achieved a much improved print quality in gray V4. This is extremely welcome and encouraging. Once FL is able to improve the shape of openings in the vertical plane, this model will be sellable in gray V4 resin, too, not just black, which is what my customers want.

Very happy with this new update.

@Cesar_Rullier, the highest point of the model (ie the point that is closest to the ‘e’ in the word ‘release’ on the left of my first photo), is 5cm above the base of the raft:

The widest dimension of the raft is 5.5cm.


Last night’s Form 3 test prints in black V4 indicate that Form 3 print quality in black V4 is approaching Form 2 print quality in gray V4 for small models with detailed surfaces (see photos below). The Form 2 prints are a bit better, having sharper detail and smoother surfaces.

Hopefully, future Form 3 firmware and PreForm updates will bring further improvements.

Test models are two different kinds of cannons in 1/100 scale, a pair of 1790 Royal Navy 12-pounder Blomefield guns and a set of seven 1790 Royal Navy 18-pounder Blomefield guns, each about 4 cm long.

On the top of the barrel is a decorative King George monogram (a stylized “GR” below a crown), a very challenging detail for 3D printers to reproduce accurately. A rendering of the actual 12-pounder model from which the prints were made is shown first so you can see what the model and the monogram are intended to look like. The 18-pounder is similar.

Form 3 prints in black V4 at 50 microns. Form 2 prints in gray V4 at 50 microns.

Hi 3d printing professionals,
I am interested in purchasing the Form 3 as my local resellers do not have the Form 2, so I decided to do some research before doing so.
From what I am reading in this thread, at this moment the gray v4 resin is still not as tuned in as it is for form 3 right? I want to print 1/6 scale headsculpts like this (sculpted by Sean Dabbs and printed in Form 2)

From your experiences with the Form 3, can any of the resin achieve such level of details as of now?
Thanks for your help.

There have been improvements in grey over the most recent firmware versions. I have not done testing to see how much it has improved, but it has improved some. That said, at present I would say you might get that quality out of black, but I would doubt it out of grey at this stage.

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Newb here.

I’ve been following this thread with interest over the past month or so. We’re looking at purchasing a 3D printer for scale models we sell. Right now we’re sending our parts out to a service bureau to be printed on a Projet 3600. The quality is great but the costs are quite high, so it’s my hope that the Form 3 is up to the task of doing our stuff. Some of the detail is extremely fine, such as panel lines at 100 um as well as other small features.

Would any of you with the black V4 resin mind printing a sample at 25um? I’m happy to pay for your time and resin. The sample is a small piece of a wing in 1/72 scale. The part is 33x43x6 mm with a volume of 1.4 cm3

attempt at attaching a picture: