Vacuum effect

Hello to everyone,

I’m here asking if other Form1 users know something about the vacuum effect that happen during peeling.

When the resin tank is automatically rotated after every layers, sometimes (in according to the mesh’s shape) I can hear a sound like a sucker removed from a plane. Also I can see the resin tank that is held, for few istants, to the silicone base of the tank. I didn’t experienced that this create problems to the pirnts, that came out fine. I tried to reduce this vacuum effect making holed the objects and creating holes to let the air flow.

But this “issue” may create a problem to the rotation motor and mechanism of the tank?

Thanks in advance for any kind reply about.

Best regards


I noticed it at my first print, My print model was hollow so it kept the resin inside it and so created vacuum. I could see the build platform was pulled down when the peeling movement happened, it terrified me, So in later prints I tried to avoid hollow object and create opening but I still heard the sound and see the platform being pulled down during the peeling. It is not only has something to do with the vacuum but also has something to do with the size of the model, If the print is large, the section area is large and the contact surface becomes large and therefore the peeling force has to be large too. In both way, the peeling motor hurts. I saw many have their peeling motor lost contact with the tank holder, I think they may try too many large prints. There should be a way to fix this problem since not all prints are small.

Hello lock,

yes, right. the “attraction effect” of the tank to the build platform is realted also to the size of print.

Is annoyng because we must find a solution and modify the mesh in order to reduce this vacuum effect.

I’m worried that after many print, the motor willbe damaged.

So… if everyone find a solution to avoid this or reduce drastically… is welcome to share the knowledge ;-

Best regards,


I don’t know when the platform level up movement happen, if it happen during the peeling then the main motor then it would have the same damage as the peeling motor…

I don’t have a solution for us end-users beyond what’s already described in shelling parts (with vent holes) and tilt-orienting them in pre-form to make sure there are no large surface area layers.

However - I did make a suggestion for FormLabs in the suggestions forum: If the Form1 could make multiple lase-and-peels passes on a single layer for those layers with surface areas over a certain limit (preferably configurable) then that should solve it.  See here -

Please add your voices and let’s see if we can get Formlabs to think about it … Obviously it would slow down some prints - but only for those that needed it. And if the triggering surface area was configurable, we could tune how sensitive it was.

Thanks Kevin and Lock.

Kevin you are right,I agree with your suggestion.

Best regards,


Hi Kevin,

Sounds cool, but before I support your idea in that thread you post, could you answer a question from me? I wonder if this really work because when every time the tank is back to level it still stick to the same layer parts that have been printed and the suction will still exist during peeling, the suction maybe a bit less bout not sure by how much but the peeling movement will be doubled or triple or many times and this will let the peeling motor busier may do more damage to it than protecting it?

@Lock - that’s a good point, contact area on the final peel of a multiple pass lase+tilt layer would be the same as for a single pass layer.

My theory is that peeling from already solidified and peeled resin is easier than peeling from freshly solidified unpeeled resin - that there is more than just suction at play - that there’s a small amount of actual bonding of resin to silicone - hence why the silicone surface  becomes marked over time, and the vat has to be swapped out.

It’s just a theory of course - the resin is quite viscous, so certainly suction is going to be a significant component of “layer grip” - but is it the major component? I’m not sure how to test it …

Also multiple passes would certainly help with the suction from hollow areas - allowing the resin to drain before the final peel.