A super thin 1mm shell Guiro that you play by dragging a biro over the ridges while holding it by the built in solid handleTricky to make well. This is my third attempt and the photos show the delaminating on the first two attempts. Printed in PLA at 185C, you need to have excellent layer registration to print this well. The hole in the end is to let the amplified sound out with the hollow rigid body acting as a sounding box.I built in fillets into the design to make the handle stronger and any stress o nit would be less likely to tear the 1mm walls of the main body. Rounded teeth would give a different sound, as would adjusting the internal cavity to have some support parts to help the top surface hold upFull size it is 90 mm long to get the 1mm walls out of this STL fileI will be improving this to get a louder sound by building in a shaped sound chamberFor my Printrbot Jr its a long stretch to put the top surface in and there is some stringing inside and a few long thin holes on the surface but overall its printed wellOther ideas at www.ajbooker.co.uk