Amplifying Motion/Solid Objects

[The Mysterious Creep]

So, for a while I've been wanting to do a project involving myself waving around one of those cheap katanas you find at malls (long story) as the primary sound source. I assumed just a base of contact mic on sword + heavy distortion (old reliable Death Metal) would be sufficient to get some texture going. Based on my preliminary tests, however (I don't have a sword yet, so I used a saw - both bladed objects with wooden handles), I didn't really get anything out of it but unchanging feedback squeal - it didn't pick up any kind of swoosh through the air or vibrations from shaking it around, only direct smacks did anything and they were pretty lackluster.

Anyone with more experience amplifying objects have any ideas? Not enough gain? Need better contact mics? A different sound source entirely? The swordplay is an essential part of the plan thematically, but I'm not married to the idea of amplifying the sword itself if that's not actually going to produce anything - the goal is just that my moves have a noticeable impact on the sounds coming out, so it's not just Star Wars Kid-ing with unrelated harsh noise in the background.

[crochambeau]

So, actual sword, right? Solid chunk of metal.

The feedback sound you hear is probably the sympathetic/resonant frequency of the contact mic and whatever vibration is possible in the sword. More gain will not solve that, it'll make it louder. Honestly, a thick chunk of metal is a pretty poor signal source on its own, so focusing instead on movement would be wise.

You could employ tilt sensors attached to the pommel, what you do with the data derived is up to you.
IR LEDs sending at an array of pickups?
Video camera feeding an image to data processor?
Smaller "whistler" or whiz toys attached to the blade?
Dynamic microphone elements attached to the blade?
Small microphone capsules (like electret/condenser) attached to various lengths of tube attached to the blade?

A lot of that requires substantial supporting electronics, but some stuff doesn't seem bad on paper.

Good luck and have fun.

[The Mysterious Creep]

Dynamic microphone elements attached to the blade?

This is an interesting one because my own extremely lo-fi potential solution was "hold a microphone plugged into the pedals and amp while also holding the sword" (transforming the sword into, essentially, a prop to guide the microphone-feedback-based noisemaking). Waves Crashing Piano Chords and early 2000's Prurient both immediately came to mind as inspirations in microphone-waggling noise. I assume by "elements" you mean the guts of a standard handheld microphone?

The other ideas seem cool too, but would require a lot more tech I don't have. Buying a cheap microphone and disassembling it? That I can do.

[Indeterminacy]

"hold a microphone plugged into the pedals and amp while also holding the sword" (transforming the sword into, essentially, a prop to guide the microphone-feedback-based noisemaking).

I'll leave this here for inspiration. I see some conceptual possibilities.