Plastic deforms over time

If i print a simple rectangle shape on Form 2 using the standart grey resin, it deforms/bends over time. Is there a way to prevent it? I print it directly on a build platform then let it be in IPA for 10-15 min, cure it in a UV box for 25-30min. After that it is deformed like on the pictures. And after time it deforms even more. Please help.

Try curing with supports on, but honestly it doesn’t seem thin enough to require it. Aside from that, I wouldn’t have a reason for it to just warp right away.

Don’t print it directly on the platform. Let PreForm orient it, and sand off the remains of the support structures afterwards.

Thank you for the reply, but it is not an option for me. There is no any other solution? The model has to be printed directly on a bulid platform.
I noticed that if i don’t pill it off platform right after print but leave it overnight hanging, it comes out more flat.

May I inquire as to why you need it to be printed directly on the platform? Print time? Supports? To me, this looks like a very simple geometry you could quite easily machine out of any material, but which you also could print the way PreForm orients it, maybe add some extra material in the CAD model, and then sand off the extra material + the support attachment points.

Agree wholehearted. The old saying comes to mind, “When all you have is a hammer, everything looks like a nail.”
Very simple shape, why agonize that you are unable to 3-D print it satisfactorily when you could easily make it out of, basically, any material of your choosing.

Thank you guys for your replies. I am aware of what you are saying. But i just want to know why is this happening, and is there a way to prevent it other than print it with and angle with lot of supports?

Maybe internal stresses due to the first layers being compressed in order to get the part to reliably stick to the build plate. It is for a reason that printing directly on the build plate is not the standard option. With a thicker plate, bending would be less I think.

Hey there @terentiy,

Thanks for your questions! The other replies you’ve seen here are correct. To clean up these results you’ll want to print on supports. I’d echo another poster above me in asking specifically what prevents you from printing this part at an angle/on supports?

Basically the supports do what they’re supposed to, and hold the part steady during printing, but also during curing. This prevents the part from warping like you’re seeing here.

Thank you for the reply. As i understanding there is no other way rather than supports. Am i correct?

You can try to constrain the part while it is curing, so that it stays flat.

What is your UV box like ? do you have UV under the part too ? Do you cure at 60° ?
Even distrubution of UV light and progressive increase of the temperature before firing the UV both help with defirmation during post-curing.

I try and keep my FormLabs parts in the IPA for the absolute minimum of time, especially with thin walled models. I use a 4 bath process, quick swill in clean IPA, no more than a few seconds, a soak in the more dirty tank, no more than a couple of minutes, agitated with a big syringe blasting IPA into the tank to keep things moving, into the next tank of pretty clean IPA for another minute or two, then a final rinse in new IPA again. I move the IPA from the clean washes into the slightly dirty tank, then into the really dirty tank, before it is disposed of. I use a few cheapo artists bristle brushes (10 brushes for £3 from The Works, in my case!) to get into any slots or cavities, and perhaps a small syringe with a blunt needle to blast out any deep pockets or areas hidden behind the support structure. Finally, air blast the parts dry (cheapo compressor from Machine Mart…) and check for any patches of resin still hanging about (they will be shiny), clean them up if necessary, the allow to air dry for an hour. You want ALL of the IPA gone, before you cure them.

Keep the exposure to IPA down to the absolute minimum needed to get all the surplus resin off.

Oh, EYE PROTECTION!!! You absolutely do not want any IPA in your eyes! Or resin, come to that!! But if you do, tell the A and E doctors not to shine a bright light in your eye, and why, it will cure the resin!!! Argh!!

Take care out there…

Look like you got some experience with some resin in your eyes)

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Correct me if i am wrong, but it seems that the deal is in the time the model is “cooling down” on the build platform. if i peel it from the build platform right after the print it deforms, but if i let it be for a few hours and get used to the room temperature which is about 15C here in Russia, it looks to stay flat after i peel it off. Can this be the problem solver. So far it seems it is.

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Luckily no, but we had it made very clear what would happen if we did, when I was first trained on the 3D Systems SLA machine, 15 years ago! We even made a little sign to hang around the neck of anyone who might end up in hospital, just to make sure!


Never had to use it, thank goodness…

Are you peeling it off from the ends? Maybe the stress from peeling it off the platform leaves a permanent bend on the uncured print? Just my 2 cents.

The higher the temperature of the part the more susceptible to warping and deformation it will be.

Even if you are not raising the temperature in your UV cure box you are going to get some increase in temperature of your part from the energy of the UV. If you don’t want to print with supports I would make a fixture to hold your part flat during curing.

Another option might be to print the part with a void that you can fit a metal plate or rod into. That will increase the stiffness and resist warping.

I peeled it from the ends, from the middle… the same result

Can you control the cooling? If you can bring the temperature down gradually over several hours, that will help too…

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