Bad Surface Finish on Form 3 Prints


Had a Form 3 for just over a week now and every part I print has a melted appearance on surfaces that have supports attached. Attached are some samples. I’ve done maybe 50+ parts and they all have this really poor definition on supported surfaces.

I’ve had a protracted e-mail exchange with the German sales office for Formlabs, who don’t seem to have much technical expertise. They suggested reorienting models, which I’ve tried, but still the same results. Surface finish on areas without supports is very good.

The German office referred this to the US engineers and their view is ‘there is nothing wrong with the printer - try removing supports and/or reducing the touchpoint sizes’ which seems like BS - I’ve used autosupport and auto orient features in PreForm and still the same crap surface finish. Am I missing something here? is it just normal that supported surfaces look like someones blasted them with a hot air gun?

Anyone with similar problems or have any ideas whether this is a bad printer or just me being dumb?

Any help/advice would be really appreciated.




Hey @GraemeWatt!

I’m so sorry to hear you’re getting some results you’re not happy with!

It sounds like you’re still in contact with our support team, but I’ll add here as well on one aspect.

You mentioned that you’ve been hesitant to do much manual support adjustment which I totally understand! That being said though, it’s worth mentioning that while the auto-orient and auto-support tools are a terrific guide, but not necessarily the absolute best possible way to support a part. It will often err on the side of caution rather than the minimum viable supports.

For this reason, it might be worth editing some of the supports, whether that’s less density, smaller touch point size, or less supports in general. A little trial and error to see what gets you closest can really help! :slight_smile:

Which resin are you using? It’s typical that supported surfaces have worse surface finish that other sides, but the amount varies, and the gap has generally been reduced significantly with the Form 3.

Sometimes, to better reduce this effect, I will find the local minima on the parts and ensure that there is a support on each local minima as well as three supports around it, generally 3-5mm away. Then I add another three around those. Because I now have the most important areas supported, I can often turn down support density across the model.

1 Like

This has not been my experience .if you look at the Form3 evaluation post you can see the surface quality of the Form3 is much worse than the form2 for small flat surfaces.There are ridges and layer shifting.

In my case adding supports did not help and the more supports you add the worse the surface quality is because of the dimples left over from the supports.the general recommendations form the formlabs engineering team has been to add more supports and/or change orientation and not rely on preforms automatic placement. What I have found it that models that print fine on the Form2 have issues with the Form3.I cant reconcile how that could be a support issue.

regardless of how much support there around the minima I still get layer shfiting or “wobble”.Just look at the form3 evaluation post so see what I am talking about.

have you printed these files on a Form2? If so did you have any issues?

1 Like

Any downward facing surfaces or surface where you place supports will have issues, the best way to avoid it is to orient the part in a way that the supports are located on areas that are easier to sand afterwards. Honestly, it works better if you do it yourself and practice figuring out the best orientation and placing enough supports in the right places. The automatic orientation/support placement isn’t going to be as good as someone doing it manually who has some experience.

I have the same mistakes and the German support says the parts need more support or / and other orientation.
All these parts have been printed very often on my Form2 without any problems, super fine surface and sharp contours.
The Form3 parts have stripes in the model and the edges are all round and washed out, nothing sharp-edged.
All these parts I print with Grey V4.

A test print with clear V4 on the Form3 without changing the supports from the Form2 shows very fine details and sharp edges.

So were is the difference between these two resins?

The form 3 I have now 5 weeks and still no good part as from Form2.
That’s just frustration.

1 Like

Thanks for the advice. It’s black V4 resin I’m using. I’ll try this. I guess I may have had unrealistic expectations about how well the machine would perform out of the box - and have been relying on Preform to make support decisions. I guess more experimentation that I expected is required. I’ve got grey V4 on order which may perform differently.

It’s certainly a shame if the print quality is worse than the Form 2.

Appreciate the advice - it is just really time consuming (and expensive) to have to experiment in this way with supports. I figured the PreForm would do a better job. It seems a shame to have such a slick piece of equipment where resin handling, process and anti print failure have been so well engineered, then find that the software implementation simply doesn’t give good results out of the box.

1 Like

At least I’m not alone. But hardly confidence inspiring.

Many thanks for the advice. Some experimentation/learning clearly needed.

I didnt mean to suggest the form3 print quality was worse than the Form2. I have done some larger pritns on the form3 and they are really nice with a smoother surface than the form2.What a bunch of users have found is that for some small parts there are problems with the form3-namely layer shifting or “wobble” of the part during the first portion of the build.We were told this was an orientation and/or support issue.I have now used almost a liter of resin experimenting with printing some simple open boxes and despite manually adding supports and trying multiple orientations including with direction for the formlabs engineering team I am still unable to get perfect prints of small boxes.At this point I have been told they are working on firmware updates to address it but for me it is a problem because the parts that I generally wanted to use the form3 for dont print well on it yet.

Maybe I was spoiled by the Form2 since everything I have had issues with prints perfectly on my Form2-even just using the preform generated supports.For me the form3 is a step backwards not an improvement.

I did print a large figure and it came out great and I have seen some other really nice prints on the forum here, but it is not as reliable or consistent as the Form2.I have used about 10 l on my form2 and I am on my second Form2 so I have a ton of experience , but despite a lot of experimentation I cant get rid of the problem with the small prints.

The reason I bought the form2 was because I needed small highly detailed parts that were impossible with an FDM printer.The form2 has served me very well and I was hoping the Form3 would be at least as good.I hope Formlabs can figure this out otherwise I suspect they will lose a lot of customers to the smaller and much cheaper machines like the anycubic.

I think the release of the Form3 was premature and it should not be left to paying customers to essentially beta test and waste resin to make the Form3 perform as well as the Form2.

Grey V4 is among my favorite resins. Black V4 is among my least favorite resins. As for the expectations, what you’re observing is not far outside of what I would expect, performance wise, from these inverted SLA printers. There are some tricks that can be done, but bottom surfaces generally worse quality than other surfaces. I’d be curious to see your prints in Grey. I suspect that they may come out better.

I’m using 0.2 or 0.3μm touchpoints at 80% for most of my prints. So the engineers seem to be correct suggesting smaller sizes.

Preform 3.2 has a trick to help with smaller touchpoints:

If Auto-Generate is used with small touchpoints Preform will usually accept all the touchpoints, however if the touchpoints are edited and one is deleted questionable minima will light up in red. Increasing the size of the touchpoints that have been marked will usually be accepted by Preform and the print will work as expected. Occasionally increasing the size doesn’t work and some minima remain red in these cases I usually leave the point at 0.6μm and Preform accepts it when the support edits are applied. I have not had one of these prints fail yet.

1 Like