My Form 3 is currently running at about 75% success rate. The main reason for that is just prints failing to adhere to the build plate. I’ll end up finding a partially or completely formed raft, stuck to the bottom of my tank. I’ve tried various different settings, I’ve tried three different build platforms, and I’ve tried moving the parts around the build envelope. Not much seems to help, except it seems to happen a little less often on the edges of the build platform. Anyone have any suggestions, or seen this problem themselves?
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Hey @lmlloyd!
I’m so sorry to hear you’re having a little trouble with BP adhesion! That’s not what we like to hear at all.
Honestly, for this sort of issue, the best thing you can do is contact our support team. They’ll be able to dig in a little deeper on the actual state of your printer and what might be going on.
If you shoot them an email you should hear back shortly and they’ll be more than happy to get you back to where you should be! 
I just got my Form3 and have had the same issue. First print was great. Super happy. Second print only half the parts printed. Cleaned it all up and had another good run and now back to being useless again. 
Did you ever get to the bottom of the problem?
It all about how you clean the plate after each print - any residual semi cured resin will result in worse adhesion. Personally I clean the plate few times (at least 4) with pure IPA and paper towels.
One other possible reason - when printer not used for long time, because the resin is kept at 30 deg Celsius and evaporates, after 2-3 weeks a very thin layer of condensed resin may occur on platform surface which for sure will compromise the adhesion. The solution is - clean the plate before the print if you left the printer for a week or two.
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Thanks. I just bought it so age isn’t an issue. I did clean the plate with fresh IPA after each test printing session. Not 4 times though I think! I’m going to clean off the rafts from the tank and try a small part to see what happens.
I’ve found a razor blade scraper works well for cleaning the build plate without using chemicals.
Something like this:
Also works great as a tool for removing prints if you use mini rafts, razor blades can get underneath which the normal removal tool can’t.
My post-print workflow is a silicone kitchen spatula to wipe excess resin off the plate back into the tank, remove the print, then scrape the area of the print with the razor to clean any specs of cured resin off the plate. I’ve had a couple of print failures due to inadequate supports, but only a single adhesion failure to date.
Thanks much … so, I tried a simple part. Still printing at 25um. This time the raft adhered to the bed and then half way through building the raft that layer stuck to the mesh. End of print! It had started to build the supports so I guess there is now tiny bits of cured resin floating about now. This leads me to suspect the Z is off as there must be a gap between layers. I await an answer from Form support to see what their ideas are.
So, 100um same print in same place on the bed … limited success. A cluster of 4 parts out of which two printed, a third has half a raft and the fourth has no raft at all on the bed. More tank fishing required! I shall try again!
Ref adhesion, i have had this issue almost constant for last 2 weeks, (had machine since october 19, and suddenly started this issue 2 weeks ago). with occassional success Have had many discussions with formlabs, still not successfully printing every time but has improved.
I think it is to do with preform rafts, have tried creating my own rafts and had more success. PS my parts are all small. Have tried merging rafts , some work. Best bit is some small rafts work, and larger ones say 50mm long can fail. So not consistent.
Any other thoughts please. Tray cleaned, build platform cleaned.
So I didn’t want to say anything until I had been able to test. They replaced my printer, and that seems to have fixed the problem. That said, I have also had some parts that print just fine with mini-rafts, but will delaminate when using a full raft. That is clearly a software issue, as the same part, with the same orientation, and the same supports works just fine with mini-rafts, and only half the raft prints with a full raft, and the rest of the print fails.
Print adhesion from the part to the build platform seems greatly increased when using mini rafts (at least with small parts). Since switching to using mini rafts for small parts, there has been no adherence issues so far. Although this does make them drastically harder to remove from the build platform. They need to include a small tab on the side of the mini raft so you can get the tool under!
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I’m having exactly the opposite problem with black V4. The rafts are stuck so hard to the build platform that I am breaking 1 out of every 3 models trying to get them off the build platform.
Is anyone else having this issue?
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I’ve found that the best way to ensure this doesn’t happen is to sand down the build plate and wipe it very clean with IPA for each build. This solves the issue almost every time for me.
Also, the best way to get parts off is to snip off a corner using side cutters and then use the thin metal spatula to get under said corner and then work your way under the rest of the part.
Thanks for the suggestions.
Doesn’t sanding down the build platform actually increase adhesion? That is the opposite of what is needed.
Cutting a corner of the raft to gain a better foothold for the spatula will be impractical for most of my designs. Nearly all of their rafts have a very irregular, scalloped shape, with no discernible corner.
Cutting the raft to remove it from the build platform should not be a requirement to safely remove the model. It certainly isn’t for gray V4. All of my gray V4 models easily pop off the platform using the spatula.
Hopefully, another solution can be found.
But thanks!
I would suggest trying it out. Intuitively you would think that sanding would increase surface energy and improve adhesion, but practically this isn’t what happens. I’ve seen very obvious noticeable improvements after doing so even with a rough grit like 400. I actually see adhesion issues less often on my Form 3, but with my Form 2 and specific resins (eg. Tough), very very small particulates of cured resin stay on the build plate. What you end up seeing is that subsequent builds get harder and harder to remove. Sanding the surface to remove any build up particulates helps refresh the build plate for easier raft removal. You just need to make sure you clean the build plate with IPA very well after every build (you should do this even if you aren’t sanding).
I have zero issues snipping the bottom of an edge and then getting a spatula in. I print a wide array of objects and encounter a lot of weird raft shapes. I’m not actually cutting part of the raft off, I’m snipping an edge to release it from the build plate, see this really old post: Different part removal technique. Very often small parts will just pop off after doing this, but large parts won’t and thus require sneaking the spatula under to remove the entire model.
Like I said, I do this all the time with zero issues. I’d suggest at least trying a proposed solution that’s working for others rather than just brushing it off.
I’ll give it a try. Looking at the old thread you linked to, I now see how to orient the cutter to get a toehold.
When I’ve tried using just the spatula to pry the model off the platform, the spatula is able to lift one side of the tray. But the rest of the raft is so fixed to the build platform and so resistant to the lifting/prying force being applied, the raft breaks, then breaks the model, too, leaving the remainder of the tray and model still fixed to the build platform. Seeing a model and raft broken in half on the build platform after a 9-10 hour print is not a happy moment.
I’m sorry to have been dismissive, that was not my intent. The suggestion to sand the build platform is what people have recommended for some time on other threads to increase adhesion. It seemed very counter-intuitive and inconsistent with my experience. What I should have done was asked for clarification. No disrespect intended and I am thankful for your thoughts and explanation.
Please be advised I have had a superb experience with the many Form 2s I have had (still have 2). The Form 2 has become the basis for my business and a significant source of revenue for a family of 6. But over the last nine months I have become disgusted with the Form 3 having lost so much money and time trying to get the Form 3 to produce a single model I can sell. After being publicly scolded on this forum by gas-lighting participants (not you) in response to my posting photos of unsatisfactory Form 3 prints following firmware and PreFrom updates, I have become very cynical with respect to any suggestions that the Form 3’s significant, very real, harmful and costly problems can and should be solved by owner/operators. I should not have responded to your thoughtful post as though you were one of those people.
It was good news this month that in another thread that Form 3 owners were finally achieving good print quality using black V4. It seemed worthwhile to try what was being reported as working well for others, though a costly try. So, after throwing another $340 at the Form 3 last week buying a black resin cartridge and a new V2 tank in the hope that the Form 3 will finally be able to produce a sellable model, I was exasperated to find that I am breaking 1 out of 3 models trying to get them off the build platform. It seems that while Form 3 printing with black V4 does achieve the desired print quality, it does me no good breaking the models to get them off the build platform. While black V4 goes very far towards solving Form 3 print quality problems, black V4 creates a different, major problem that has to be solved.
But your suggested solution to the new problem sounds practical and helpful so I will give your technique a try.
IMHO, there’s a lot to like about the Form 3. For my business to continue to succeed, the Form 3 needs to print models as well as the Form 2 at all resolutions in all resins, without breaking models. It is getting much better.
Thanks!
Just a second to using nippers under the edge to remove parts. This is the only way I have ever removed parts! I don’t remember where I saw it, but early on with the Form2, that just became my standard way of removing parts, and I swear by it.
As far as sanding the platform, it is balancing act. A pristine new platform is very smooth, and has decent adhesion. But as it is used and scratched up, it can get rougher, and actually have more adhesion. Sanding will lower that adhesion. On the other hand, if you use the same platform with lots of different resins, even cleaning it thoroughly, It can get a thin film of cured resin on it, that actually makes parts not stick to it hardly at all. You can tell when this has happened, because when you sand the platform, it smells strongly of cyanoacrylate, and you can actually see the discoloration on the sand paper. When that happens, sanding will greatly increase your adhesion.
If the point sizes are reduced to around 0.3mm the prints can be removed from the supports before the rafts are removed from the build plates. This works well for small parts with relatively simple geometry.
I presume every one has seen the Form 3 intro video where the part is just twisted off the supports?
I’ve definitely encountered situations in which I’ve had to hammer and chisel the raft off the build plate. Those were stressful times. Without fail, every time that’s happened, I sanded the build plate down and the subsequent build was perfect. Sometimes I get lazy and don’t sand the build plate regularly and then eventually will get a build that’s harder to remove. Again, without fail, when I sand and clean the build plate, it always “resets” back to a good build.
And no worries about feeling dismissive - that’s definitely how it felt, but I understand the situation and I’m just trying to help.
Oddly enough I’ve actually had pretty good successes with the Form 3. I’ve had 100% print successes so far. I did have to RMA my initial machine at first due to some weird artifact caused by dust in the LPU but since then it’s been good. I definitely have seen some of the same artifacts present in these threads and I also do see softening of edges a bit. Quality has definitely improved over updates. I don’t use Grey so maybe it’s much worse. There are still pain points like long print times and resins that haven’t been fully dialed in yet (I use all the engineering resins and standard black). However, I will say that - at least for what I do - the ability to push support touch points down to 0.3 or lower and the elimination of peel forces in shear have a huge benefit for me as an engineer. So I’ve actually been printing mostly on my Form 3 and I prefer to over the Form 2 right now (even though the F3 isn’t perfect yet).
I agree that when the build platform gets scratched up that can increase adhesion.
I don’t agree with your last point. At least from what I’ve seen, it’s usually the opposite - subsequent builds get MORE adhesion and not less.
Maybe this depends on what resin you’re using. I use almost all different resins and so maybe they have some weird cumulative effect, or this only happens with engineering resins or something.
If you sand the plate down with 400 grit, clean it thoroughly with IPA and then run your finger along it - it will actually feel very, very smooth.