Thanks. I thought about the spring idea myself. And strings with those stupid caterpillar windings give me grief elsewhere.
Now that I have this beast (Nyx is her name) built to my satisfaction I want to screw it up. Has anybody converted this to a bowed instrument? No doubt the bridge is the wrong shape and possibly the curvature of the neck is all wrong but I like the unique. And fretless possibly would sound more mellow.