Issue with printing tensile bars vertically

[kspattas 0]

Hello, as part of my thesis, I have to print tensile test samples in vertical and horizontal direction. The vertical ones turn out fine but I am having an issue with the horizontal ones. As you can see in the pictures below, when it gets to the small overhang at the upper mid part, I get some sort of warping and layer displacement. So far I have tried:

-Increasing brim adhesion lines

-Lowering the printing speed from 30 to 10 mm/s

-Lowering the printing temp from 210 to 202 degrees celsius

-Printing with support

Even though the first two helped a little, I still get the warping. Do you have any other suggestions? Any help would be greatly appreciated. I have also attached my STL file.

 

Tensile specimen D638 type IV.STL

[gr5 2,172]

Print slower.  MUCH slower.  Try 1/2 or 1/4 speed what you are printing now.  You can also lower the acceleration and jerk by 2X.

 

In cad, add some support.  the part is stronger where it is wider and it should be okay to add some support there.  Make the support get very tiny where it attaches to the main part - maybe 1mm attachment.  Make the attachment be like an angled post that angles in and helps prevent your part from wobbling when it gets taller.

 

Also you can print much slower.  i'm guessing you have a printer where the bed moves in the Y direction.  This moves the part and so it wobbles more - align your part so it lines up such that it is stronger in the Y direction if this is the case.

 

All supports should be at least 1/5th as wide at the base as tall.  So they should actually be cone shaped ideally.