Rod Piezo with bolt/nut bridge

I've made a couple bridges for rod piezos like this where I attached steel rods to aluminum with epoxy to create sort of side rails to hold the rod then sat brass rod on top of the piezo. The first one I did I used a bolt for the strings to ride on instead of the brass rod, but I used a dremmel to grind a flat spot on the bolt to better transfer the vibrations to the rod piezo. Sorry I don't have a picture of that.

You can hear what it sounds like in the video I just posted. I think it sounds quite nice for a humble piezo rod. Here's a link to the video if you can't find it here on the Nation. Ceramic Body Guitar Demo Video

Also as JL said Shane had a video about putting a bolt on the top of a rod. He somehow had created a channel that the rod sat in, but he didn't show the machining process on the bolt.

There is a Shane Speal video on this. You stack 3 cutoff wheels on a dremel to cut a groove in an eyebolt. I can post a picture if that helps.

Another thing you can do is if you are doing a neck-through design, place the rod between the neck and the underside of the box (making a tight groove in the neck for it to sit in) at the point where the bridge is.  I've done this loads and as long as there's enough pressure on the rod you can get a great sound.