build platform doesnt raise during printing

[jensen]

If I start printing the build form moves in the z-axis towards the clear window and produces a vacuum which inhibits the build platform to raise up during printing. Is the z- axis motor to weak/defective to overcome this vacuum?

[fromFDMtoSLA]

did you level the buildplate again?
i get good results by leveling with a folded piece of paper (= two sheets).

[jensen]

yes, i did it with one piece of paper. I elevated due to this issue slightly the build platform before printing but i noticed that once the print is started the build platform is moved towards the clear screen. 

As I said I even have issues to detach manually the build platform from the clear screen.

[fromFDMtoSLA]

did you clean the FEB (as you say the "clear screen") and the buildplate with 99% IPA before first print?
and how did you level the buildplate (like the Elegoo-YT-video)?

[jensen]

did you clean the FEB (as you say the "clear screen") and the buildplate with 99% IPA before first print?
and how did you level the buildplate (like the Elegoo-YT-video)?

Hi,
no, I didn't clean any part with IPA, eventually, that's why there's a lot of surface tension causing this issue?
I calibrated the unit as indicated in the video: I moved it down with a loose head after I laid a piece of paper on the bottom. After reaching equally the very bottom I tightened the screws.