Tweaked to fit the raspberry pi's I've encountered (4 so far)

The original by redpeppr has not (IMHO) got the recognition it deserves, probably because people don't search for raspi but the full word raspberry

Print and Use :-)

1x bottom
1x top

First gen (uploaded as refixed) has no clips so you may need to use a rubber band to hold it, my next tweak is to encorporate clips and thicken the walls a bit.

Don't use the clips version yet - it's hosted so I can get help fixing it.