I have the Trio oyster shell feeder and thought I would share an easy way to add under shelf coated wire baskets to it if you have that type of feeder. Unfortunately Nature House discontinued that item but if you have one this would be easy and should work good for the martins to help keep them off of the ground while nest building.
The baskets can bought at most home improvement stores.
I zip tied them to the mounting bracket under the feeder. The feeder is connected to an old Tri-tel pole that I can raise and lower to add oyster shells or nest building material.
your idea looks good;;;;I just used a plastic dishpan and drilled holes in it an riged it under 1 of my m12k trio;;;robins were trying too build nest in it but I deterred them;;;;jr2
PMCA member; s 2011 2 pair fledged 3; 2012 3 asy pair,4 sy pair,2013 8 asy pair,6 sy pair;2014 19 asy pair,2 sy pair