I need to drill 3/8 holes as straight as possible end to end from the bottom in twenty finials like the one pictured. They are just a hair over four inches tall for size reference. I have tried a couple different jig ideas but neither have worked very well. The first really didn’t work at all.
The first involved having a slightly undersized hole in a piece of wood that was cut in half and acted as a vise around the waist at the bottom. The piece of wood rested on the top of a U with the bottom of the U being drilled for the top ball of the finial to set in to keep it centered.
The second jig was similar but used vee blocks.
Because of the end use, keeping the hole centered for the entire length of the bore is going to be very important.
I’m open to ideas.