Ahoy mates, print this pirates cannon and protect your desk from scurvey seadogs.
Use black for the barrel and a grey or brown for the rest. All the parts should snap together but if they are a little loose then a drop of supaglue works wonders.
Print at 0.2 layers, 3 perimeters and 50% infill and support. I printed mine on a Printrbot with a 0.4 mm nozzle.