Building banjo #44, part 5

On the evening of the 24th I spent most of my time marking and drilling holes, and sanding.  My first task was to fit the neck to the pot.  I began by marking the position of the square hole where the dowel stick passes through and drilling most of the way through with a spade bit in a regular handheld drill.  I stopped about 1/8″ short of the inside of the rim.  I have found that no matter how well I try to fit a block behind the hole to prevent damage as the bit emerges I still get tearout more often than I like, so a couple of banjos ago I started this new method.

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Then I set the rim down again and inserted the pilot(?) of the spade bit back into the hole from the inside, coming down from the top at an angle.  The resulting hole would not be satisfactory for something like inserting a dowel, but since I will be carving it out to a square shape anyway it is more important to protect the surrounding wood than to maintain a straight hole.  I have wondered if a regular twist drill bit would not tear out as much, but I don’t have a 3/4″ one on  hand to try it out.

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Then I used a jigsaw to cut up and down from the side of the hole, across the grain, to begin to approach the final square shape, and used a chip carving knife to finish the job.  I don’t usually sand inside the hole, I just carve it till it’s big enough and leave it at that.  I really like this knife. the company that made it seems to be called Two Cherries, and it takes a good edge and holds it better than other knives I have used.

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Then I measured from one side of the hole around the rim to the other side, divided than number by 2 and marked the vertical line where the endbolt hole would go.  I put the dowel stick in the hole and eyeballed the length it should be cut to and made a mark that was my best guess.  P1240005.JPG

I trimmed the end off the dowel stick by degrees and kept re-checking the fit. I also had to chip off a bit of glue that had dried around where the dowel stick goes into the neck.  I should have checked for that when I glued it in but I was too fixated on the alignment to remember it.  Once the dowel stick was cut to the right length I took a look at where the dowel stick came to on the rim and drilled a hole, and then drilled the hole in the end of the dowel stick to match and screwed in the hanger bolt.  Then I put the neck back in the rim and put the endbolt ball on to see if everything looked right.

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Then I put the dowel stick yoke in and marked the spot to drill for the pin, and then drilled the hole with the dowel stick sitting on a hardwood backer block to prevent tearout around the hole.  I drilled all of these holes with the handheld drill.  In the picture the screw is not tightened to bear on the shim, it’s just sitting there.

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Next I put a sanding drum in the drill press and trimmed the end of the fretboard so it was more even.  I may have to do this again during final setup but at least it’s close now.

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Then I drilled the previously marked holes in the peghead, and eyeballed the position of the hole for the 5th string tuner, all with a 3/8″ drill.  The peghead holes should be 10mm, but it’s easy enough to ream them out to fit.  I will show how I install the 5th tuner in the assembly and setup post.

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Then I put the head and tension hoop back on the rim and marked the locations for the bracket shoe bolt holes.  I used the speed square, though a machinist’s square would be handier, I think, but I don’t have one yet.  The masking tape is to hold the tension hoop in place so it doesn’t slide around as I’m marking.

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Then I took the rim to the Shopsmith and drilled the holes.  I like to set the table to a 1 degree tilt away from the headstock when drilling these holes because the bolts are .210″ and the nearest bit I have is .214″, and I think that tilting the holes slightly helps keep the bottom of the shoes from pulling away from the rim under tension, but I don’t know if it really helps or not.  I only started doing it recently.

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The last thing I did was to cut out and glue on a heel cap on the neck.  Because the rim is fairly deep there’s room for one, so I got a scrap piece of cherry burl to match the peghead.

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