Prints Sticking to LT tank FEP

I’m having repeated issues with a 3rd party resin sticking to the tank FEP (I assume the LT tanks are FEP film?). When I use a new bottle of resin and a new tank, I get a few good prints. After a few prints I get failures, and now I can’t seem to get anything to work.

I’m using open mode, and if I use one of the faster profiles like White V1, my prints either break off part way through, or pull off the platform. If I use something like Clear V2 or Gray V2, it sticks to the build platform, but also sticks to the FEP. It’s obviously taxing the Form2, making loud banging noises and barely getting the print to break loose. I sometimes get successful prints, but I get a lot of junk stuck in the print that looks like torn off layers.

So here’s my question - what can I do to make the peel easier? When I hear the loud banging noise and see what looks like missed stepper motor steps, am I hurting the machine?

I’m using 3dresyns, and I have light blocker and fine tuner, but neither seem to help. I’ve also used an external heater to make sure it’s warm 25-30 C. It still seems to be a choice between tear-offs and extreme sticking to the FEP.

The banging sound is skipping of the stepper motor. It should not damage the machine.
Several 3rd party resins have issues with the LT tank. Did you try the orange tank with this resin?

If you have an empty cartridge, try running the part in “closed mode” and see if it works better. The wiper can reduce stick. However, the release force will be higher with LT tanks than the orange PDMS tanks.

Thanks for the info. I haven’t used them for this resin. I’ll give it a shot, going through more tanks is better than failed prints…

PS - FormLabs if you’re out there listening - I find myself really liking the ‘low force’ idea. If your open mode on the Form 3 has at least heater and wiper/mixer/whatever, I’ll order one. On the other hand I’m getting more annoyed by the day that I can’t use the heater and wiper in the machine I already own.

Fantasy 2 mentioned in one of his other posts that there is the option of a third party universal cartridge. Its a great piece of kit and restores the functionality of the printer with the dispense system, the wiper and the heater. Resins work much better with it. than just open mode.

What type of resin are you having the fails with (not the make - the type, ie flexible, grey clear ect.

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Thanks, I’ve ordered a universal cartridge, it’s on the way.

As for the resin type, it’s this semi-high-temp resin:

I just changed my tank (new LT, didn’t have a spare PDMS tank handy) and put in fresh new resin, and got a great print. When I get good prints I like this stuff - not their most heat resistant, but good enough for what I’m doing and not quite as brittle.

I’m scratching my head, wondering if I did something to ruin the resin, the tank, or what.

Is it possible the resin itself is going bad after a couple days in the tank or leaving the resin in hurts the FEP?

I started off with good prints, and only started messing with things after a few days when I started getting repeated failures. And as I mentioned, now that I went back to new tank new resin, it all seems good again.

I just made a really interesting discovery. I shined a light through the window under the tank, and the mirror underneath looked strange. I took off the window, got some lens cloths and wiped the mirror with 99% IPA. With one wipe it became dramatically apparent that the entire mirror was covered in some kind of gunk. Whatever it was, it wiped clean easily.

I noticed small extra bits of cured resin around the base of my prints. The main body of the print was fine, so I didn’t pay much attention. Now I’m wondering if that haze on the mirror was spreading out the laser, and partly curing the whole tank every time I printed. Is that a thing that can happen?

Are my galvo mirrors likely to have the same haze?

If something managed to haze up your whole main mirror (an unidentifed volatile compound in a 3rd-party resin?), it’s quite possible it hazed up your galvo mirrors too. It’s not a bad time to try an optics test print (ideally with Formlabs Clear v4 because that’s what’s standard, and having it standard makes it easier to interpret).

With regard to the tank film, even though LT tanks generally last much longer than regular Form 2 tanks with Formlabs resins, Formlabs doesn’t make any claims when it comes to 3rd-party resins, because anyone can sell you anything. Can you get any information from 3dresyns about whether they test their product with LT tanks in Form 2 printers, or whether they recommend the standard tanks?

Form 2s don’t need 3rd party resins to haze up. At least the optics window is notorious for hazing up from inside.

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It’s true, 3rd-party resins aren’t the only thing that can get the optics dirty, and they might not necessarily do it faster than it happens from other circumstances.

Just an update for anyone interested, I’ve had pretty good success since cleaning off the mirror. The real test will be if things are still good in a week or so.

I’ve also got a PDMS tank on the way, and a universal cartridge. If I see anything dramatically different with those I’ll post another update.

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