Vectr.com

Many months back briefly talked about Vectr.com.  This is a free website that create vector graphics.  Vectors are pretty cool since the can be scaled to any side.  So they are great to lets say T-shirt designs.  I am think it would all so be great for 3D models.  Something like a simple logo.  Then export it as an .svg flie.  Which can be easily imported into Tinkercad.  Going to give this a try and see what I come up with.