Face Planarity

[daap]

Hello, I am trying to print the 12x9x16 mm3 object shown here (Form 2 - Clear v4 - 25 um layer).

I am attaching the .form file: prova.form (273.5 KB)

It is extremely important to ensure that the two faces highlighted in the attached screenshots turn out perfectly flat.

The surface facing away from the printing bed turns out perfectly, while the other one presents a defect consisting in a “domed” region which protrudes as shown in the attached pictures.

It should be noted that for design reasons the printing orientation cannot be changed with respect to what is shown in the photos. Furthermore, the 4 custom tabs (in the four 2 mm ID holes), along with the triangular structure at the bottom are custom-designed supports, removed manually in post processing (the holes are then tapped and deburred). The 4 custom tabs in the 2 mm holes could be removed, but I am not sure whether they are the culprit.

Can someone please helping me in figuring out what is causing this defect which makes the said face non-perfectly flat? (Light bleeding? Insufficient stiffness in the first layers? Bad supports?).

Thank you and best regards,

DP

[Steven_Hines]

Hard to say if it is the problem, but it appears that in the area you highlight as being domed has, at least until the first set of holes, a rectangular suction cup facing the tray. The forces created peeling this might be a cause of the distortion.

One option would be to rotate the part 90 degrees using the “Orient Axes” tool. In other words, have the other face oriented toward the wiper. You would still have the suction (sounds like you can’t change other orientations) but maybe having the peel forces perpendicular to the face would help.

[microdev]

I agree with Steven. Maybe rotate the part so the print starts on a corner. The orientation in the image results in the largest cross section possible. Try to minimize the cross sections to prevent distortion. Alternatively, add a mm to the part wall and machine or sand it to tolerance after printing to ensure it is within spec.