e-drum trigger pad

A well functional e-drum trigger pad. It's still work in progress but I'm very happy with the results so far. I'm going to build a whole e-drum set around this, including a kick-trigger and cymbals. You can watch the progress on thingiverse and for most recent changes look on my git repository:
https://github.com/Piesi/pE-Drums.git

You are of course also well welcome to contribute!

Non printed parts:
-Threaded rod (6mm,130mm)
-4 M6 75mm bolts
-6 M6 25mm bolts
-1 M6 50mm bolt
-M6 nuts
-Sensor piezo (like this one http://en.wikipedia.org/wiki/File:Electronic_component_piezo.jpg)
-8" meshhead
-a jack socket.
-sponge or felt (between the sensor and the mesh, hope to find
a printable solution soon)

The printed parts of my version weight about 375g.