Adjustable Ipad Stand

I'm just starting to dabble in 3d modeling/printing and this is the first design I've uploaded on Thingiverse. I designed it so that it has enough room to be sturdy and to be able to hold an Ipad (even with a magnetic smart case attached). Also, I didn't want it to require any external connectors so all 3 pieces fit together by themselves.

Please don't hesitate to give me any feedback/suggestions to improve the design. Thanks!