My experience with the Form 4(B) so far/ Semi-Review from a Semi-Industrial User Perspective

[eaglechen]

Alrighty all, I appreciate the efforts of everyone still reading this, this will probably be one of the last larg-ish updates I will make on this thread. It is about 3 months since I have met with Formlabs representatives to discuss feedback, no meaningful changes in Form 4 printing behavior and print setting profiles have been made as of end of September 2024. I did a little more printing and testing, and here are some conclusions I will draw for now.

First things first, I will pretty much completely backpedal on Precision model resin, it does not fix most problems of dimensional accurate through some more testing. It is a little better than most general purpose V5, but more like 10-20% better and not the previously though 75-90% jump in accurate. Here is what I mean:

Firstly, here is a thin and square thing in precision model that the $500 FDM printers today will eat for breakfast, if you look closely you can see that in reality none of the edges are straight:

About a 2-4mm curvature away from a straight line on both axis, drew some dramatic red lines to illustrate the warping direction:

For reference, model was oriented like this:

Form 4 has so far struggled with this in every material I have used, the expanding area where the
model first attaches to the supports bends from the rest of the part. The expanding areas that are supposed to be straight instead forms a curvature that results in 2-5mm of inaccuracy over just 100-150mm. This also occurs in chunky models:

Left side of the building is lower than right from orientation.

Btw, this is all with precision model, of which exhibits by far the best stability behavior yet still does not achieve the 0.2mm or 0.15% advertised. Every other material is much worse. Furthermore, I discussed above about how presion model and general purpose material spontaneous warps over time, and here is an example of something I got mostly flat but curled itself after being in a room for just 1-2 weeks:

Also I did dip my toes into Tough 2000 and realized it has similar poor accuracy as general purpose V5, and declined a client project. See examples below, obviously this part is supposed to be square and flat:

Could not get it to print straight or cure flat despite being on supports.

So where does this leave us?

So far, my experience has showed these materials do not print the advertised accuracy:

1. Grey V5 (consistent 2-5mm warping on straight edges, expanding area print issues)
2. Clear V5 (by far the worst, even worse than grey v5)
3. Tough 1500 (warping almost as bad as grey v5, added curing reliability issues, poor overhang and bridging performance worse than general purpose materials)
4. Precision Model (slightly better than grey v5, still consistent warping across 100mm edges of 1-3mm)
5. Tough 2000 (warping about as bad as precision model, added high difficulty in warping during curing).

By the way, I will add the reason I rarely print directly on platform is this:

This did came out mostly flat printed on platform, but curled dramatically during curing so much so that the model cracked from internal annealing forces. Angling on supports and curing on supports helps a lot; furthermore, a lot of geometries lead to much easier supporting on angel and I think this is a big advantage of SLA to print weird geometries.

Speaking on internal annealing forces, I do have a hypothesis of a potential cause of this warping, Form 4 flashes an entire layer at once, generating a lot of internal forces that seems to add together across many layers, pulling into the part and bending (Form 3 obviously does not do this as it scans each layer slowly and progressively so I have never really have seen this issue on Form 3). Coupled with v5 general purpose materials that are designed to print and polymerize fast, well, perhaps here we are. This might mean a long road to a true fix to this issue. But hey, I’m not an engineer and this is speculation at best and conspiracy at worst. I do think this means a long, long road of software and hardware optimization before useable reliability for me.

At the moment, I cannot live with a near 10K system that has delivered about 30% reliability of client deliverable parts. I have already begun conversations to look elsewhere. This all may change, but I do wish Formlabs best of luck with improving this system and you all to hopefully not be having too much headache.

[ytw]

I bump into this thread after I saw the Form4L news. As a former Formlabs user - Form2 and Form3, I find your comments very interesting and I definitely share a lot of your feelings and pain.
I’m in model toy business, semi production and semi hobby, my first printer was Form2 and it was great for doing prototype. So a few years later when Form3 is out, I bought it with confidence and thought it would help improve things. It did not, lots of lines at contact area. Their support has been good at throwing free consumables to me but no fix to the issue (I had three years printing experience back then). So I ended up selling the printer.
Now I just use cheap printer like Elegoo and Phrozen and I never complain since they are so cheap and do the job for me as prototype. I recently used the Elegoo Saturn 4 for massing printing two hundreds model pieces and then send them to paint, predicable outcome and not much to complaint either.
Now just sharing a few cents for the warping issue. I have the same problem at bottom as you. and I doubt there’s a good solution. Your piece seems bigger than mine so your issue may be worse, but for something like the US flag, I would print it straight standing up with the shorter edge parallel to the resin tank. It would not bend on X or Y, I will see some tilting at Z direction at the contact areas at the corner, so I will sand it later, of course sanding will eat part of the model, so I make a bit more in design and even pinch the model a bit in opposite direction, just to compensate the printing tilt. But, to get a perfect straight bottom line, it always requires sanding in my workflow.

I also hold my expectation for making production pieces using any 3d printing, it just don’t compare with the traditional mold injection, especially for something smooth and straight, it just won’t come out easy and nice for me. I’ve come to this conclusion after trying a few times printing inhouse and also outsource to industrial printer in China. I see all kinds of problems, first batch is good, second batch turns bad, etc.
I’m still curious to see if Formlabs can come out with a stable machine/workflow, I’m been looking at their automation and seems very interesting and worth the investment as long as they can produce predicable pieces as advertised.

[eaglechen]

Morning!

I think you are absolutely right. pretty much currently it is about an identical experience honestly between printing on the Formlabs machine versus $250 printers. Those things are so cheap that a couple of failed printed I throw away from my Form 4 from can buy one of those… If anything, you can probably tune one of those things to actually achieve something a little better than anything I have seen off my Form 4 in terms of accuracy. I have seen some parts off a $500 printer from Loctite materials with straighter edges and sides better than anything I have printed off Form 4… Of course, if something fails it’s a couple of dollars and a non-event.

I am convinced 3D printing is becoming two polar opposites – either go buy a $250 printer to get some occasional working parts and do all tuning yourself or you will need a $250K machine to actually have any reliability to get what people actually think a 3D printer should do. Trying to go in the middle like Formlabs to get an industrial experience for cheaper usually ends up being paying consumable costs similar to $6-figure machines for an experience not much superior compared to the $250 printer one.

The issue is now client expectations are absolutely insane. Ironically, everything I have shown you above can be easily made on an industrial FDM machine (or even cheap $250 ones I can build in my bedroom) WITH much straighter edges and square sides. I almost bought one of these industrial FDM machines, the issue is now people are so used to hypothetical results from desktop LCD machines and injection molded parts costing $2 I cannot sell and hope to make money with FDM at all. The surface finish and accuracy of an industrial SLA/ MJF machine is a minimum expectation of most people.

I have already printed the American flag in the orientation you described and more. I am also aware that it can actually be printed straight on platform. The reason why you see some of the weird orientations above is curing – if I just toss something flat like that into the cure it will curl upwards like a potato chip; ironically these orientations I have posted above allow for the most detail to be preserved, good support material interaction, and the best chance of the support material pulling the model into an accurate cure. The issue is also I am not at liberty of designing/ redesigning my client’s parts. Everything I have shown you above is more from a part of what I can do that I can publicly disclose. Client parts suffer the same issues, I just cannot easily disclose those here; the problem is if I tell someone who have been regularly outsourcing with large service bureaus with large SLA/MJF machines with a lot of success I need to redesign their parts and basically machine them down/ extensively sand to get them to work, no one will do business with me… I don’t think I am asking for too much in terms of getting 0.2mm+/- accuracy like Formlabs advertises. It does not need to be perfect, but selling an “industrial” 3D printer and then having to post-process that part and carve it down to make it work is not worth it and destroys the point of a 3D printer in house completely. I might as well go get it machined or outsource the part from a bureau with good printers that can actually do it at that point…

Again, I have seen even desktop FDM printers deliver straight edges and reasonable results for everything I have shown above. I have outsourced some of the results to professional service bureaus on polyjet and MJF machines with excellent results. Additive will never be as good at injection molding; but you can get somewhat close with those machines to at least a visual scrutiny. Formlabs claim they can outprint those machines at a fraction of the cost and it seems that is just not reality.

The Formlabs automation solutions seem to be essentially putting a robot over a Form 3 printer… therefore any problems of the Form 3 itself (which are many) will be present. I am not convinced anyone beside dentists who print little teeth on platform (no support material required, super easy parts) would ever realistically benefit from this. I am even less convinced of reliability from this.

Curious that essentially problems of warping and a lot of problems of the Form 2 are still even present today. In the ideal world the new 4L is the perfect printer for me – large volume, fast material swap. The issue is I am even more skeptical of the 4L’s ability to achieve a remote amount of accuracy or reliability. I don’t see any obvious design or print setting changes between that and Form 4, meaning pretty much every accuracy and warping problems I have experienced here will essentially be amplified.

Perhaps the true path to “industrial” reliability Formlabs keep pushing is complete material and ecosystems changes and we are truly years and years away before that becomes reality. Sad I went from cautiously hopeful from the beginning of this thread to now looking elsewhere.

[rkagerer]

Thanks for all the detective work and documentation presented above. It sounds eerily familiar to when the Form 3 first released.

I owned the Form 1, 1+, 2, 3 and 3L, and was an early-adopter for most of them. The 3 was released prematurely, and the first 6 months I owned that printer I produced very few successful production parts, but many hundreds of test prints in an effort to characterize issues with accuracy and print quality, and to explore how to work around them. Ultimately I’d say it took at least 2 years before they dialed in the print settings - and provided the needed adjustment knobs - to the point where I was content with the product.

I was preparing to pull the trigger on a Form 4L, but am going to hold off for the moment. If anyone from Formlabs is reading this, the warping issues eaglechen described - namely at the corners of prints, and the photos showing how straight edges aren’t straight - are a red flag for me.

I hope your engineers are working aggressively to make improvements. I really would like to upgrade, as in many respects the Form 4 seems like it’s engineered to be a solid platform and it closes the gap on some of the annoyances that make me love my Form 2 more than the 3 (like more leak-resistant tanks).

In the meantime, has anyone come across other posts from Form 4/4L users with alternative feedback, analysis or in-depth accounts of their experience?

@eaglechen, have you tried some of those prints on a Form 3 (or Form 2)? If so, I’d be curious as to how the results compare. (When the Form 3 first came out I did a whole series of comparison tests).

I’m wondering to what extent the warping phenomenon is exacerbated in the new process, or if it’s similar to the earlier generation printers I’m already familiar with. I’ve often been able to mitigate by adding supports (sometimes even chunky custom structures), printing direct-on-base where geometry allows, reducing post-cure temperature or curing in liquid, etc. but it sounds like you’ve tried all that.

[eaglechen]

Evening!

Form 4 hardware and cartridge system is much better, feels a lot more like an actually seriously engineered piece of equipment vs in 2 or 3 that felt like something a startup built (because it kind of is).

I owned and used Form 2 and 3 both extensively, the best (recent) results I have obtained is V4 general purpose material printed on Form 3, which seems to do better than Form 4. A lot of more exotic materials like tough and high temp have the same warping issue across generations.

Unfortunately my current belief is that is this a problem inherent to inverted vat polymerization method, and cannot truly be solved without big material and setting changes. Printing direct on base or partially curing are things I have tried, and only really works on case-by-case basis and is pretty experimental depending on part geometry. I am unfortunately not at liberty to redesign a lot of the parts I print (which are in all honestly not very challenging and a desktop FDM printer can even do very well now). I do custom supports and a lot of work as well for most prints, which large has no effect on this issue as the warped parts seem to usually stick to the support columns but bends entire columns; again, don’t expect perfection but the accuracy is pretty disappointing when a supposedly turn key cannot make a straight edge. Formlabs have promised a fix, but did tell me there is no timeline for that when I met with their representatives (this was 3 months ago now).

I have said somewhere before Form 4L on paper is the perfect printer for me: large volume, good material choices, high-ish speed (no doubt a lot of work accounting for post-processing). Unfortunately I don’t really anything on 4L to mitigate this issue at all. When you print large, peel forces and no doubt warping and curing pain amplify greatly as well (as was my experience with 3L). This is the reason I am very skeptical of 4L accuracy and have no bought one yet.

[Friedl_1977]

Hi @rkagerer

Disclaimer: VERY new to SLA printing!!

My advice, which is only that, is that it depends on whether you want to print square corners and 4 straight edges, or whether you are printing ‘curvey-thingies’.

If it is the former, again in my experience which is just that, you might have a difficult time getting things the way you want them to be. At best I get three straight sides, but the side attaching to supports closest the build platform, well let’s just say I doubt it be straight.

I have tried to print a sacrificial “breakaway tab” on the parts to ‘absorb’ the initial warping, with mixed success. This does add to you post processing of course.

As the only reason I bought this printer was to print enclosures for PCD designs and parts that had to be dimensionally accurate, I at this stage, have no other option than to print directly on the build platform. This of course has some advantages (fewer supports, less resin) but the downside, you will have to deal with artifacts such as elephants foot and ugly surface finish (depending on the condition of your build platform). I have wasted way more resin than I’d care to admit on trying various angles, tilts and stupidly many supports which did not, in my case, yield any positive results. If you plan on printing directly on to the platform, I would suggest investing in the Flexible Build platform if you can, it will make your life a while lot easier. I am using the normal one, it can be tedious getting the part off the build platform.

There are some articles on how to reduce the elephants foot (flashing) effect, but I have not been able to dial it in perfectly yet. I really do not mind being one of the early adopters of the Form 4 providing of course support will work with us (aside from giving us the stock standard “refer to these guidelines” and “refer to those articles”) and give us the support (and listen to feedback) needed to help make this printer what I believe it could be.

Now the good news, if it is ‘curvey-thingies’ you want to print, you are in luck, the printer does a very good job at that

On the left is Astronaut Phil printed with default settings in Grey V5. On the right is the FDM version printed on an Ultimaker printer.

Regards,
Friedl.

[jakabasej4]

@leonhart88

I have a friend who works with 3D Systems machines and he mentioned that none of the industrial grade machines or resins require a thermal cure to reach their maximum mechanical properties, so they don’t experience the same issues as Formlabs users.

A quick google showed this: here 3D Systems Support

That’s an interesting insight!