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My kind of metal work, where precision is measured in 64ths.
Cole Banjo Dowel Stick Wedge
© Frank Ford, 2008; Photos by FF
I've often said that I think I tend to approach metal work the same way as I do wood work. While that habit has finally turned a major corner, it still has its place. Here, my job was to recreate a missing brass wedge used to secure the neck on this fine Cole banjo from the 1890s. It's a real pleasure to work on instruments of this vintage, made in the day when factories were staffed by practitioners of skilled hand craft.
No doubt the original construction consisted of using a stock brass fitting and hand carving the stick to fit it, but that's not what I'll be doing here. In working with old instruments the general idea is not to change the original if at all possible, so I'll make the wedge to fit the stick.
First a quick measurement - accuracy wasn't a big deal here, I just needed to know how much stock to cut off my 1" x 1" brass bar.
When other "metal heads" visit my shop one comment I often hear is, "Jeez, WHY do you have SO MUCH stock, especially brass - it costs a fortune." Well this is why. I wanted to do the job right away, and ordering stock would take a day or so, or entail a costly (in time) road trip.
Sawing off the stock on my vertical band saw. If I had the room, I'd surely get a horizontal saw, but that just ain't in the cards.
Over on the mill I squared the cut ends and reduced the dimension to much a much closer fit:
I measured the approximate angle on both sides of the stick, and the "dovetail" section appeared to be 15 degrees on each side, or something very close to that:
I have this pair of aluminum plates that fit my milling vise, and I add new angled cuts to it when I'm about to need to position a small piece of work:
The sine bar got me dead on the 15 degree angle, and I milled a pair of slots.
Now, I could clamp my brass block securely at the angle I wanted, and I could reverse the jaw plates to achieve the angle cut on the other leg of my new part:
That was the easy milling part. Next, I had to establish the wedge angle so that when I pressed the wedge in place it would tighten the neck securely to the banjo shell. I just used my little woodworking bevel gauge:
And, I stuck the brass part in the vise, held it against the bevel gauge and tightened up:
No problem to mill the face flat at the correct angle:
A quick trial fit:
One photo I missed was me filing the surface of the piece where it would fit against the curved surface of the shell. I did that by hand, trial fitting it as I went.
OK, this as my last milling cut. I set the block at an appropriate angle with the help of a small angle gauge, and milled the top of the piece to the approximate angle I'd want for my finished part:
There wasn't much "meat" left there to get a good grip, but by taking it slow and easy, I milled the top surface to an angle"
From here out, it was familiar territory indeed. File, file, file - until the contour of the wedge matched the original style:
I didn't have an original on hand to show off here, but I've seen lots of these banjos, so the contours came easily.
A few more trial fits:
And, nice and easy, it tapped in place, wedging the neck solidly against the shell:
Next, a bit more buffing and a trip to Avenue Plating to get a nice layer of nickel to match the rest of the banjo.
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