Cura 2.7 generating support against build plate under model, why?

[Camaroboy383 1]

Having an issue with the new cura 2.7... I never had this issue with the 2.5.0 version....

Here is the issue.... cura 2.7 has now found it necessary to build support against the build plate under the models I've printed.... basically it's generating a support built raft under the face of my models.... anyone have any idea as to why? When models are entered into cura they are flat against the build plate.... these particular models need support touching build plate so cura decides it should toss support under the model? If I turn support off it prints just fine right against the build plate as it should....

Before you ask the simple stuff...

Yes raft is turned off, and skirt is on,

Yes the model is sliced 90 degrees to the build plate,

Any ideas? Thanks in advance for any replies....

[gr5 1,877]

Go to cura settings (not profile settings) and there's a checkbox - make it so cura allows Z to go negative. Then click on the part and the "move" icon and set the Z to a slightly negative value. Maybe -0.1mm. This will probably fix your issue.

[Camaroboy383 1]

Go to cura settings (not profile settings) and there's a checkbox - make it so cura allows Z to go negative.  Then click on the part and the "move" icon and set the Z to a slightly negative value.  Maybe -0.1mm.   This will probably fix your issue.

Sounds like a great place to start... thank you for the advice... it was strange to me that the software update all of a sudden brought this issue out... I currently have a 4 day tpu print going right now so I'll post my results when I can start a new model...

Thanks again and I'll keep you posted