Primitive Penholder

So, my son got home from school and 'wanted to print *something*' - and he settled on a pen holder. Having looked at the various things available here, we decided that they were all too complicated and we'd design our own (in OpenSCAD)!

So, here it is - parameterised so that you can hold as many pens as you like :) It's pretty small, but seems to do the job - it can also be stuck on a vertical surface and still holds the pen/pencil !!