Tuesday, July 21, 2015

Jarde Oboe - Left F Modification

This was a great project I got to do recently - adding a left F lever to an older oboe that didn't have one. It used to be you could order all or most of these parts from Fox and build the mechanism yourself, but they've recently made it more difficult to do that so I started from scratch. I got a chance to break in the new (old) lathe by trying some single-point threading and making hinge tubing from a solid rod, using a technique I read about from another tech. Plus I inhaled a lot of nickel dust cutting the keys out of a solid bar.

When making the posts, the rough shape was first turned on the lathe.

The threads on the posts were cut on the lathe to match the existing posts already on the instrument. The posts were going into new holes, so it would have been possible to tap them with any thread, but for consistency's sake I kept the same measurements as all the existing posts.
The final shape was filed by hand using a bench motor.

New post holes were drilled on a press, then the holes were tapped and the posts were checked for fit. The "caps" on these posts were left on to provide something to grab on to while they were repeatedly removed and reinstalled.

This swell post-drilling jig (made by Matt Slauson up in New York-thanks Matt!) keeps drill bits aligned to the center line of the posts while drilling holes for the screws.

Evidently I forgot that I had a camera for awhile, so there's a few scenes missing between this picture and the last one. But you can see the hinge tube mounted between the posts and through the key. A new screw goes through the posts and hinge tube. The lower part of the left F touchpiece is shaped and waiting to be brazed to the upper part

A view looking down toward the new post for the rocker part of the mechanism. Originally the post in the center of this picture was threaded to hold a screw, now it's been bored out so that a longer screw can pass through and thread into the far post.

A side view of the touchpiece, now with the upper part brazed to the lower part. The other keys have also been reinstalled.

The rocker mechanism engages with a new tab brazed onto the original F key. A long screw passes through the D trill touchpiece (on the right) and continues through the rocker and into the new post on the left.

The rocker passes under the long rod for the Eb/Low B/Low Bb keys

A general view of the new touchpiece and rocker, all finished and ready to ship!