One more thing: levelling is important.
You want the first layer SQUISHED a bit into the glass so that there are no gaps between stripes on the bottom layer. Especially at the edges where all the lifting force occurrs.
And another thing - using less infill will help as there is less pulling force on the upper layers.
Recommended Posts
gr5 2,224
No fan is good. 110C is good. 235C seems cold. Here are some ideas:
1) Use ABS glue. Google "abs glue" and use that! Clean glass well before applying abs glue.
2) Use brim. In Cura it is very important to use a brim - this keeps air from getting under the corners - once 1mm lifts the whole thing lifts. Also brim rounds the corners as rounded corners stay down better.
3) For parts >100mm wide, consider a heated chamber. Just cover the sides with plastic food wrap and put a box on the top. Wait until the air is at 40C before you start printing.
ABS has a roughly linear expansion coefficient. In other words if you graph density versus temperature it is roughly a straight line. However shrinkage while ABOVE the glass temperature (around 100C) is not important because above the glass temperature ABS is soft enough that it flows a bit and the forces that cause lifting are small and not a problem.
Once ABS cools to glass temperature, the remaining cooling to air temperature (100C to 20C) is a problem. If you can heat the chamber to 60C then you will get half as much shrinking force. Much hotter than 60C and the steppers can't handle it. Besides the air just above the 110C print bed should be hotter than the other air.
Link to post
Share on other sites