We previously advocated soft fibre-board for making nest concaves, here. Up until now, we have made these by gluing together two layers of fibre-board to make a blank 25mm thick, then scooping out the concave on a lathe. Here we have a better idea.
|The tool mounted above a blank, and the tool in action, right.|
|The cutting edges are bevelled at 30°|
A friend of mine has made a tool to be used in a pillar drill. Setting the pillar drill to its slowest speed, 210 rpm, it does a nice job of very quickly excavating the concave, without creating clouds of carcinogenic dust.
The material of the blade is 3mm gauge plate.
It takes less than a minute to scoop out each concave.