A very simple bottle holder, maybe not so pretty looking as others here but with some goals to achieve: It should print without supports and does not need many retractions (even if my printer would not have any problem with retractions).
The inner size of the holder part is 25-26mm. You can adjust this with FreeCad 0.18 if you change the dimension of "Pad005" of "Body002", it is set to 30.5mm (minus 5mm the width of the outer shell).
Part 2 must be rotated 180° for printing (in X direction for example).
I have used the really cool feature of Slic3r PE, Layer editing, to make the top 2-3mm of the objects very smooth. The rest can be easily printed in 0.28mm for example (took about 8 hours with 50mm/s for me).
Used 4 bottom / top layers and 4 perimeters (4 perimeters are important!).
I designed this in FreeCad and is my first design there, where I used only a very few measurements / constraints. The whole thing is mostly designed visually because I wanted to find out how I can design this at all (especially the "slide in holders") with FreeCad 0.18 and "Datum Planes" - so it started as a proof of concept. And because it looked not really bad, I decided to print it and publish it also here.