Cura and Repetier different result

[wrtdgary 0]

Hi I am new to 3D Print.

I am having trouble of setting up the print model.

Recently I start to print with Cura software, And I've found out that the mashine will always print an extra line outside the model.

I did not set up the line and did not showed up in my Cura slicing. But when I put it into Repetier I can see the line clearly.

It is actually at the layer 1 of Repetier but nothing else. And the layer one of Cura starts from the layer 2 of repetier.

Does anyone know what couse the problem?

 

Thank you