Lost my cap, the only I found on thingverse was stl only and I didn't like it for being not rounded enough, so I made my own.
No supports needed.
At the time of designing this thing (2016) I have not yet calibrated my printer well, so the openscad code has extra variables to correct that. The variables are unset in the published code though.
The author marked this model as their own original creation. Imported from Thingiverse.