Thank you all. I’ll take a look to those posts and extensions.
I misunderstood the “blueprints” and not all corners needed to be round.
For the rest of them I did as DaveR suggested in first instance, I used guide lines, and click on the inference point and click again when it told me it was a tangent arc.
I got this error and I scale it x100 and after finish the shape I scale x0.01 to fix it, not sure if it’s the right way.
This is the final result.
And this is the file with the result.
solido13_3.skp (466.8 KB)
I took the exercise from here.
Sorry because it’s in Spanish but I can translate it for you if someone needs.
PS: sorry if I give 1 like to all posts, but everybody had contributed.