Can harps (Büchsenharfen) are an easy build from cans, threaded rods (diameter ø 4/5 mms), tightened to the can bottom using wing nuts & washers. I made a lot of those, free tuned a well as in semitones. Free tunings are much more interesting, semitones are more practical for music production ;)
Tools: Metal drill bits or a piercer, respectively drill or hammer. Bolt cutter or metal saw.
People have rests of threaded rods in their basements available for little money (see yellow pages), however the max. diamter, that works with cans is around ø 6 mms. That sounds a bit dull already, thinner is better. Threaded rods from stainless steel or brass sound longer and more brilliant, than the zinc-plated ones.
Here’s a video of me and Suetszu jamming on them.
