Once I had the electronics built and in a box I needed a frame to hold them all. The major requirements were:

• can't use metal fasteners to attach the sense coil to the rest of the device (since they'd reduce the sensitivity of the device)
• the device's frame needs to be built for free

I had a broom handle, some pvc pipe and fitings, and a handle from an old drill lying around and they seemed like they'd work for the handle/frame. Rather than explaining how everything fits together here's a pic of the assembled frame:

To attach the sense coil to the end of the pvc pipe I needed a way to join the HDPE drywall bucket lid to the pvc pipe, at a useful angle. To mount the lid at an angle I built a bracket thing out of some pvc faux-wood trim (available at home-depot if you don't all ready have it laying around), which is neat because you can work it like wood, but it glues to pvc pipe with normal plumbing glue. Here's a picture of the bracket thing before I glued it together:

the above two images should give a good idea of how it fits together.

Finally to attach the sense coil, I used a couple of plastic bolts from a toilet seat. This let me bolt the HDPE lid (blue) to the pvc (white) without gluing, or using metal fasteners right in the middle of the sense coil.

That's it for the build, so, did it work?