This purports to describe the construction of a sort of hammered-dulcimer utilizing pieces of metal conduit pipe in place of more conventional strings. It is pitched same as a conventional instrument, playing in the keys of D, G and C. One look at the beast would impart enough info to build it, but failing that here, will do my best to twist words to accomplish the same end.
Logs can be a bit twisty, so long as they are reasonably straight in one plane.
Turn each till they sit the flattest. Precision is obviously not important here. Best to build this on a flat surface so that the instrument will not rock. In like manner notch and secure the remaining two thinner logs. Repeat process on rightmost log's top.