Printing with Polycarbonate keeps warping I'm trying to print a large piece with polycarbonate but it keeps warping, I'm using a Taz 5 printer and setting 290 C in the extruder and 145 C in the heating bed. 

Other setting I have are:


printing speed: 20 mm/s
layer height: 2.5mm
infil: 20%
brim: 15mm


Can anyone tell me any tips or suggestions to avoid warping?
Adjusting the design may also be able to help limit the amount of warping you get.

One of the major causes of warping is upper layers contracting while cooling when laid down over now-cool(er) lower layers which no longer contract so much but are still thin enough to flex when subject to tension along their upper edge. Insertion of strategically placed gaps in upper layers can reduce the tension such layers are able to apply.

I was printing some long thin beams in ABS. I inserted horizontal-axis holes along the beams (making them look a bit like LEGO Technic beams rather than solid pieces). It did the job for me.