Drilling Jig

Larry Mueller, who is an outstanding oboe technician and an equally skilled tool maker/designer, let me try out this prototype work fixture for holding clarinet, oboe, and english horn joints for drilling. He does a lot of tone hole replacement, a skillset I've yet to develop, and this tool is ideal for doing that sort of work when one doesn't have access to a mill with an indexing head (which I don't). But we've both worked separately on installing Left F mechanisms on oboes, and the jig is also well-suited to drilling holes for new posts, so I got to check it out with that purpose in mind. Unsurprisingly, it's well thought-out and well made, and easy to use. I tested it out on a junker clarinet body and was pleased with the results.

I don't have a mill (yet) but I do have a decent drill press, and the jig is useful even with this simple set up. A compound slide table allows the joint to be lined up perfectly under the chuck, and the jig itself allows you to rotate the instrument without losing your X and Y axis alignment. It's also rigid enough to hold that alignment during and after drilling.

Drilling test holes with a homemade cutter, based on a design that was also shared by Larry. The cutter makes a hole for the post threads and puts a relief at the top to fit the flange (base) of the post. The cutter is visible at the top of the photo, and in most of the other pics.

The jig also allows cuts to be easily repeated. I wanted the relief at the top of this hole to be a little deeper, and was able to line it up in exactly the same position under cutter to do that, after having rotated it out of position to check the finish on the holes.

I threaded these posts into the holes without tapping them first, to see how it would go. The left one is almost straight, the right one isn't close. The radial alignment is off on both of them, because these posts were pre-drilled. A functional post can only be drilled after it's installed to insure the alignment will be correct. We're just messing around here, though, and I had these pre-drilled posts laying around.

This hole did get threaded, with a spare post that I turned into a rudimentary tap.

See? Just cut some notches into the threads and you've got a simple wood tap that will work in a pinch.

It was much easier to get the post straight in the threaded hole. This one came out beautifully.

This is the kind of tool that could vastly expand the work you can do.