I'm quite new to using 3D Drawing programs, except a bit of work in Google's Sketchup. As I'm trying to draw a model that should be 3D printed, and heared that Sketchup is kinda bad practice for this, I started using a different program.
I've started drawing in 123D Design, this was quite working, only now I ran into a problem. I've made a mistake, as the right border is to small, and I need to stretch this. This should be quite easy if the corners weren't rounded. But I cannot find any way to stretch this border with 3mm while the corner is rounded.
The same has to be done for the rear plate.
As I couldn't find out how to do this in 123D Design, I've also tried doing it with Autocad. In here, I found the Stretch command, but this doesn't seem to do what I wish to do.
Sorry for the probably little simple question, but I couldn't find how to do this by myself.