Form3 - let's do a proper comparison with Form2 - how good is "LFS"?

Hey All,

I wanted to see a proper comparison of F3 vs F2 with the same part, showing how the F3 can achieve equal or better results but with significantly fewer supports and finer contact points.

There hasn’t been a lot of feedback from F3 owners here, but what there is has been only mildly positive through to negative , so without any solid evidence of the F3 benefits above the F2, I asked FL to cancel my F3 order.

The conversation with FL sales surprised me - they said let us send you sample parts first, I said sample parts aren’t much use, what I’d need is a proper comparison with the F2; an F3 part with supports still on, and the Preform file for the F3 and the STL file so the community could validate the F2 could not achieve the print without denser supports. They’ve just replied: “ok send us STLs”

Game On!
So this is an appeal - do any of you have a sample part you’d like printed that you think would be a good test case for the F3’s Low Force Stereolithography ?

For example a part with thin fragile sections that you want to minimise support contact points on. Or perhaps a section of a mould that currently needs support contacts on a cavity surface - maybe the F3 could print it without those supports.

A part you want printed with fewer supports than you can currently achieve on the Form2. A part (and Preform file) that you have already optimised for stable printing with the fewest possible supports.

I’ll pick one of mine and if you guys can come up with another one, lets see what FL sales can do on the F3.

Then I’ll post the results here, and maybe some of you could confirm you can’t print the same parts on your F2 without denser supports.



Let us know what STL you end up sending in to the sales team. I’d like to try running a similar set on prints on my machines (Form 2 from January 2015, refurbed December 2018; Form 3 production prototype from April 2019). I’ve been doing a bit of direct Form 2 / Form 3 comparisons over the summer.


This is exactly what I would like to see, I also want to hold my F3 order until I see convincing result.

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No-one has a sample they’d like to put in the F3 F2 shootout?

I emailed the sales team yesterday with two candidates. One I’m currently printing a lot on my Form2 - I’ve attached a picture of the best orientation and support scheme I’ve been able to create - The teeth are the essential feature that really cannot affort to have supports attached, but in this orientation the quality of the tail suffers because it’s so thin and that flat-on orientation doesn’t print very well.

[EDIT: you know how talking through something often answers your own problem? I’ve just realised that tilting the fish on another axis - on it’s side opposite the fin curl should help with bad results on the tail, it does mean a couple of extra supports on it’s side, but that’s ok - anyway - I’d like to see how the F3 does with the Fish in the orientation pictured]

The STL and Preform files are about 10MB so here’s a download link for the STLand also the Preform file

The other file I sent them is something I threw together in 5 minutes as a kind of torture test, lots of thin processes pointing in most directions. I haven’t tried to print it on my Form2 - I’ll try to find time over the next few days for an attempt - I’m hoping it’s nearly of on the edge of printable on my Form2 - but we’ll see, maybe it’s not hard at all…

the thinnest process is the lower middle rod at 0.75mm - here’s the STL test.STL (166.1 KB)


So FL sales replied with a Preform file for the fish that they were going to print on a Form3 - however nearly all the support contact points were 0.6mm and a couple were 0.45mm: sales F3 Preform file1

This is a huge backward step from the support structure I use on Form2 which uses 0.3mm and 0.15mm contact points - and I said so.

They responded very quickly with sales F3 preform file2 in which they have changed the contact point size to 0.2mm for new supports, but left the existing contact touch point sizes unchanged. No actual support changes have been made to the file.

This exercise now seems at risk of devolving into a large waste of time with no useful conclusions - so apologies to those who might have been interested in an F2-F3 shootout - it’s not happening in this topic. I’ve asked sales to cancel my order.


I’m reaching out to our EU sales team to see what I can figure out for you. I want to make sure the test we’re doing is actually telling you the information you want to know.

I thought I’d give the Wolfish a try just to see how it turns out on my Anycubic Photon.

Here is the model with the supports already generated. I used the default “Light” supports, which have a contact diameter of 0.40mm.

Print time is 2:47 hours, whether I print one, or if I pack the whole surface, with 9 of them.

And here is the printed model. My phone camera simply doesn’t do well with small items, but here are a couple of views with the supports still on, and without. I think it came out nearly perfect, and without anywhere near as many supports as preform tried to add, hence a lot less dimples to clean up.

I primed the fish this time, and took a few more closeups. The model was not cleaned up, so the small dimples left fro the supports are still there.

Can you export the supported file as an STL? If not, I will try to copy the support points based on your images and print on Form 3. Unfortunately, the most precise resin on the Form 2 (Rigid) does not work on Form 3 so I am stuck with Grey.

What was your layer height?

Are you asking me or Kevin?

The reply does not do a good job showing which comment I replied too, sorry. You, Dudemeister.

No problem. Here is the supported model. I couldn’t upload it, it was larger than the 7.5MB allowed here, so I put it on Dropbox.

My print was done at 0.05mm

White, 0.05 mm z resolution. Form 3. I put in my own supports points to mimic Dudemeister’s since his file directly didn’t print. Touch point size was 0.4 mm. The file supported by Formlabs also printed fine, but definitely over supported. Resolution looks great, definitely hard to tell from just pictures and the fact that it is a different material from the translucent green. Supports removed just by twisting part and came off pretty cleanly. Residual support areas look similar to Dudemeister’s pictures.

Curious that the file I posted didn’t print. It should have.

I exported quite a few supported models from ChiTu Box and printed them on my F1+ directly on the platform without any additional supports.

One of my problems with Preform is that you don’t have control over the size (diameter) of the support branches, nor do you have control over their placement.

I’m not referring to the placement of the contact point, rather the placement of the vertical branch/stem, which sometimes is so close to the model that it fuses to the side of it leading to a ruined surface. With ChiTu Box, you can literally grab the branch and move it outward if you think it’s too close.

Additionally, you can control the size of the branch and save it in 3 different defaults (Light, Medium and Heavy)

I purchased black resin just to test it out. I can happily confirm, that Form3 25um black looks almost identical to Form2 grey 25um. The test part is 17x9mm.

Its not “crisper” than the Form2, but at least I have hopes that the From3 can match the performance of the Form2 in the future. Now they just need to get all of the resins to the black performance!

Just as a reminder: most resins are still terrible on the Form3!
These are my findings:
Grey: 100um is nice, 50um and 25um are terrible
Clear: 100um is nice, 50um is OK but worse than F2
Rigid: 50um is OK but worse than F2
Black: I cant compare to Black on F2 but 25um is very nice and as good as grey on F2

Hope this helps!


I’d say with recent versions of firmware and Preform, Black on the Form 3 is about as good as on the Form 2. There might be some minor remaining edge cases with surface ripple, but they’re barely noticeable, and I’m starting to see cases where LFS enables overhangs that would require more support on the earlier model. Here are a few comparisons:

Form 3 vs. Form 2 Faceoff!

Bad prints out of brand New Form 3

Bad prints out of brand New Form 3

I’m hopeful Formlabs can achieve the same level of improvement with other resins.

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Am I missing something here - The Form2 at 25 in Grey looks WAY better than black. I haven`t used black - is black inherently soft for details and usually bubbly/pitted? I mean Grey is leagues better.

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I’d say it’s a mixed bag. Surface finish on the From 2 definitely looks better on that test, but it looks like edge sharpness might be a little better on the Form 3. My problem is, the difference is certainly not clearly $3500 in the From 3’s favor.


In the beginning when the F2 was released black would be better than grey.

However, these days grey and model resin print the best on the F2. So a best comparison would be F2 grey and F3 grey prints.

I’d be happy to run a comparison if someone wants to buy me a Form 3 tank for my Grey resin :wink:.

I’ve done many test prints with every firmware since I use mainly grey:
with 100um the Form 3 is very nice and quite accurate.
50um is bad
25um is terrible.

I dont have the images on hand but might follow up; but grey on Form 3 is only useable at 100um.