Steampunk Train Whistle

thingiverse

I designed this prop for my daughter and it's based on an old train whistle. It holds a compressor blow-off tool in its body and uses compressed air to create the sound of a train when the handle is pulled down. The five printed parts are assembled using 3mm screws and 4.2 mm knurled insert nuts. The whistle's components include M3 brass knurl insert nuts with an outside diameter of 4.2mm and a length of 5mm, available on eBay. I referenced the work done by MikeP-NZ, published on April 20, 2013, to create this train noise.