[Woodwind instrument making] Ball post drilling fixture

Hi,

I recently showed a tool designed for turning small balls. It is explained here :
http://www.homemadetools.net/forum/m...946#post109053

This tool is especially useful for turning ball posts, which are the small pivots used to support the rod of a key on a woodwind musical instrument.

Here is a batch of nickel silver ball post blanks : (they are quite small, the ball is 4.5 mm in diameter.)
http://www.labellenote.fr/file/homem...turel_0001.jpg

For supporting the rod, which is actually a long 2mm diameter screw, one ball must be drilled through, 2mm diameter, and the other ball must be tapped M2, so drilled 1.5mm.
It is quite challenging drilling such small holes through a ball shaped piece, and it is quite critical to keep well centered.

So I imagined this little fixture for that purpose, which turns out to be very effective.
Here are all the parts:
- a main body (out of hex stock)
- Two small screws, center drilled, and with a conical tip. They will act as drilling bushings to guide the drill bit.
- A tapped transversal support, that will hold the ball post while being drilled.

http://www.labellenote.fr/file/homem...turel_0002.jpg

Here you can see how the ball post is hold in place inside the fixture.
The two screws will guide the drill bit. One is center drilled at 2mm, and the other at 1.5 mm, so the same fixture can be used for the two different sizes required, you just have to revert it upside down.
http://www.labellenote.fr/file/homem...turel_0003.jpg

Everything assembled, ready for drilling.
http://www.labellenote.fr/file/homem...turel_0004.jpg

one drop of oil
http://www.labellenote.fr/file/homem...turel_0005.jpg

And here we go
http://www.labellenote.fr/file/homem...turel_0006.jpg

What we obtain :
http://www.labellenote.fr/file/homem...turel_0007.jpg

Perfectly true :
http://www.labellenote.fr/file/homem...turel_0008.jpg

I can show here an example of what the finished key looks like (on my last instrument) :
http:///www.labellenote.fr//file/Lut...e_M14_0006.jpg

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Thanks Christophe Mineau! We've added your Ball Post Drilling Fixture to our Luthiery category,
as well as to your builder page: Christophe Mineau's Homemade Tools. Your receipt:

<div id="blocks"> <div class="block b1 pngfix"> <div class="bimg"> <div> <a href="http://www.homemadetools.net/homemade-ball-post-drilling-fixture"> <img src="/uploads/213465/homemade-ball-post-drilling-fixture.jpeg"/> </a> </div> </div> <div class="head pngfix"></div> <div class="left pngfix"></div> <div class="right pngfix"></div> <div class="blockover b1 pngfix"> <div class="title"> <a href="http://www.homemadetools.net/homemade-ball-post-drilling-fixture">Ball Post Drilling Fixture</a> <span> by <a href="http://www.homemadetools.net/builder/Christophe+Mineau">Christophe Mineau</a></span> </div> <div class="tags">tags: <a href='http://www.homemadetools.net/tag/drilling'>drilling</a>, <a href='http://www.homemadetools.net/tag/fixture'>fixture</a> </div> </div> </div> </div>
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Beautiful work Christophe

Doug

Christophe
Beautiful work, I'd like to see a little bit more of how it is done.
Very nice work
Nelson

WOW, once again Thank You,

Ralph

I had a somewhat similar problem. In my case, I needed to drill two orthogonal holes through 1/8" diameter brass balls used as part of miniature universals. The jig and procedure is described here...

http://www.homemadetools.net/forum/d...-spheres-27292

Drilling larger holes in larger spheres involves a different approach...

http://www.homemadetools.net/forum/d...-spheres-27291

beautiful work, Christophe.