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Form 3L Issues


The Rigid 10K test I made came out perfect and also easy to remove from the build plate.
Out of 8 resins I tried so far only the white gave me issues.

I do want to try a test in height and possibly across both LPUs to see if I get some of the layer shift issues reported here. I’ll do so when I get something to print vertically and keep you posted.

Overall I’m happy but also always scared of the outcome. We’re dealing with lots of resin per print (plus 1L+ for the tank) to have it randomly fail.
The only concern I have are the tanks which, as most of us described, are a lottery when it comes to quality.

I do have to state that while I usually use 0.35 of touchpoints in the Form 3 I’m conservative when it comes to the 3L and use a higher 0.50 setting. Probably it would work with 0.35 as well but I’ll keep those tests for another day.


I’ve been using 0.4mm on all my prints without issues thus far in terms of support failure on the 3L

Interestingly I feel like the supports are harder to remove and more cured than my Form 3 parts in the same resins.

I noticed this when the Form 3 first launched as well. I’m not sure if Formlabs is over curing on purpose to minimize failures and then dial back the laser power or exposure over time…although it’s also true that when I got my Form 3, my Form 2 laser power was probably dwindling so this could just be conjecture.

Here’s another pictures of some of the deformation I see on the bottom of my tanks (enlisted the help of my wife to grab the pictures because it’s so hard to do my oneself). This is brand new, only one print done on it.


Does anyone have this kind of issue with their build plate?
It seems mine (with only 128 hours of printing) is starting to lose the sealant. Never had this happen with Form 3 build plates so I wonder…

(sorry about the crappy exposure)


Hello Eks,
I have just checked my build plate and I don’t see any sealant or something else. The joint around is clean and flush.
Do you think it’s resin residu, or another type of build plate V1 with sealant? Because I don’t have any sealant or gap around it… This is weird. Maybe ask support for this? Because it will be full of IPA I guess?


It’s not resin, that’s for sure. It feels like some sort of sealant.
Here’s some photos:

  1. After removing it (it was peeling away anyway):

  2. This is the opposite side of the build plate (you can see the sealant there):

  3. A lateral side. Doesn’t show much sealant, only a few bits here and there:

I’ve contacted support but still no reply.

If you look at the photo I posted before you can see that it actually has a hole beneath the supposed sealant. So yeah, it will get filled with IPA :confused:


Ok thank you for the explanations and photos. I think we have seen this on the forum but for the Form 2 build plate?
Of course, you should ask for a free replacement if FL don’t have a solution for you. Annoying… I understand.
For now, maybe cleaning everything and putting a sealant, again, which could resist more… It looks like they have patched some badly fabricated build plates by this.


Here is the first print on my brand new Form 3L printer. Laser Calibration Test Piece - Default


All looks good so far.

Then I printed the test piece - default.

Then I printed the test piece again - rotated 90 degrees about the Z axis. It failed 3/4 through the build. But what did print is showing the same issues as the first test piece.

There is a serious depression on these parts. Is this the result of a defective tank/tray?



I have been sent 4 trays now and not one of them reads correctly.

Pretty soon Formlabs is going to have to admit there is some serious flaws here. I get that some are printing ok with it but i am not impressed.

Sucks big time.


I would say yes, it’s possible. Please see the picture below. This is what I was obtaining from my first Tough 2000 resin tank. Just in the front of it. Severe deformation. After replacing the tank, everything was printing fine. You should try something else to print. And note where the issues are occuring. Which zone? At the beginning, I tought it was a front LPU problem, but it seems to be more a ''not visible on the membrane" defective tank. Because it was not occuring on my 2 others resin tanks. You can read ( if it’s not done yet ) all the posts here, in order to learn what problems or success we are obtening. You can open a ticket with the support team. they will answer the next day, approximately.



Question for the masses…brand new tanks. Is the film underneath tight when you look at it before you print with it or is already sagging?


I posted about this above, some of my tanks brand new always have deformation, significant sagging, or wrinkly areas brand new.


I’m also curious for those who are getting successful prints - have you printed something really tall yet? All my failures or noticable artifacts are on tall parts.


Most successful user here that I can see is All On Scale with good prints


Yeah his models looked like they were perfect. I’m curious specifically about tall, thinner models.


Tech support looked at my parts and said that I might be getting a wrinkle in the tank film. They are sending another tank.

Too much sag, and the film might wrinkle. Too little sag, and the layers may have a hard release. At the very least, Formlabs probably needs to better control film tension during production. This is probably why some tanks work, and others don’t. I would die cut the film oversize, including alignment holes around the perimeter. Then, I’d attach the film to an assembly fixture that would maintain exact dimensions or tension during tank assembly. After the film has been bonded to the tank, the excess film could be trimmed away. The vacuum formed tank is also too flimsy to maintain predictable film tension. Perhaps they could add ridges to the longer sides to increase the frame stiffness.

If you try to measure the width of the film, it would measure the shortest along the edge, where it is bonded to the frame. It would measure somewhat longer in the middle, where there is maximum sag. Now imagine running the LPU back and forth accross the film; how can this possibly happen smoothly?


They are for sure.

I’ve been successfully using 0.3mm at around 0.8 density on my Form 3, 3L and Form 2, with a few slightly larger manual ones in key locations (e.g. minima). The 0.3mm ones on my Form 2 detach way easier (sometimes accidentally) and examining them the ones from my 3L almost look like they’re slightly bigger than the ones from the Form 2. But that’s just anecdotal - I haven’t attempted to measure.


To be honest they look the same to me and, besides the issue I had with white (hard supports, raft stuck hard to the build plate), they’ve been quite easy to remove in a single go most of the times. I don’t have a Form 2 to compare but they’re behaving the same way as in the Form 3 (both the support removal and the raft removal).
Again, the white sucked for me so I guess it depends on whatever voodoo we may face.


There’s something bugging me since day 1 and I couldn’t find anything about it.
Do any of you happen to know what this thing is for?:


Their response was that the “wrinkles” shouldn’t cause any issues and that the failures are happening from invisible tank issues. But I agree, I can’t imagine how a deformed or wrinkled secondary film could not impact things when the LPU is rolling across it. My analogy was that of tensioning a crumpled up piece of paper. It’s not going to behave the same way anymore.


Interesting to hear all this from you and @rkagerer. This is definitely all anecdotal of course, but I do remember when switching from the F2 to the F3, supports were more difficult to remove in the beginning and parts felt harder out of the machine.

The Form 2 has a lot of laser issues that could result in soft prints though, so not really a fair comparison…but so far my experience is that parts on the 3L feel more cured than on my F3.

Maybe I just haven’t done enough prints to break in the machine yet and I’m going on a small sample size.