In this view, I am drilling three holes on each side. Try and make the end holes the finished size if possible. I am using a special carbide sheet metal stepped drill. A custom purpose hand cutter is available for this task (about $100).
Holes are drilled vertically down through the plate as the sides of 'ff' holes are vertical.
Using a special fixture and a magnifier light, I next use a jewlers hand saw with special fine tooth wood cutting blade. Install blade so it cuts on the down stroke and use a hand held support stick beneath the cut to help support the very delicate wood.
The trick here is to always cut in such a direction as the cutting action tends to hold the wood grain in place ( 'with the grain'). Because of the many grain direction changes in this operation, you must continually think about the cut at each point. Failure to do this will resut in the wood spliting off at critical points.
The blade supports pivot so that the blade can be re-oriented as need dictates.
This is my 'ff' hole cutting holding fixture which screws to the violin making table when in use.
For older eyes, I recommend a good quality lighted magnifier light. For you younger builders with (still) excellent eyes, enjoy this blessing while you have it.
In cutting out, do not quite take the line, but just get close to the line.
Modified 9/2017
Page O16C_47
..Drill # 42 ( 0.092" D.) pilot holes in each ff hole center for hole cutter (hand operated).
..Use special fluted cutters: 0.250" diameter in center; 0.280" diameter in upper ff hole; and 0.335" diameter in lower holes.
..Go 1/2 way through from each side to get clean cuts.
