Constructing a Mountain Banjo

Here is a compilation of all my posts about building a mountain banjo.  Please feel free to share it with others, and don't hesitate to leave a comment if you have questions.

Building a Mountain Banjo: The Pot

      In an earlier post I wrote that the true essence of the banjo is taking what one has, and making music out of it.  That is what the earliest banjo players did with their instruments consisting of a gourd covered in skin, a stick for a neck and some strings.  In time the banjo evolved into the modern banjo, which is probably what most people think of when a banjo is mentioned.  However, the were many intermediate styles and designs that developed after the gourd banjo and before the modern banjo.  One that has always interested me is the "mountain banjo."  It is a unique banjo design that was intended to be easily constructed with limited tools.  Unlike some other designs, it does not require laminating ply to form a circular pot nor does it utilize a gourd or grain measure for the pot.  Instead, circular shops are cut our of solid wood stock.  It is probably not the strongest method, but it works.  I have wanted to build a banjo for some time and this type of banjo seems like one of the easiest to build.  In addition, I also like the old fashioned look and sound of this banjo style.  Today I had a little time off, so I just decided to start building one, but I have very limited experience building instruments.  I once built a cigar box guitar, but that is it.  I have documented what I have done below.  As I build more I'll be sure to post updates.  Anyway before I get any farther, I figured I should add a video so you can hear a "mountain banjo."

      So there it is, the "mountain banjo."  Now you can tell why I want to make one.  In this post, and others to follow, I will document my construction so you can learn from my ideas and especially my mistakes.  I have to admit, I'm not doing this on my own.  Randy Cordle's free plans and construction advice posted on Bluestem Strings are what I'm modeling my banjo after.  I hope to document my work in a little more detail than the video for those who are not familiar with woodworking (although I am no expert).   I have also heard that the Foxfire Book III has plans for a banjo like this, but I don't know for sure.  Sadly, I don't own that book.

      Today, I wanted to gather some materials and at least get the pot started.  I wanted to use scrap and salvaged materials in order to keep the cost low and also because that is how these banjos were often made.  People used what they had.  I didn't have any 1/2" solid stock wood but I did find some scrap 7/16" birch ply in my garage.  It is not traditional in the sense that it is ply, but it is very traditional in the sense that I'm using what I have on hand.  Of course, I had to make some minor adjustments to account for the missing 1/16" but that wasn't too hard.  I'll also have to figure out how to seal the plywood on the side, but that is a challenge for another day.

      The first thing I noticed when looking at the plans was how many circular cuts must be made.  Instead of using a jigsaw, scroll saw or coping saw (which would all work) I decided to use a router so I could get a nice clean, almost perfect circular cut. To help me, I decided to create a simple jig.  It looked a little like this.

My jig is shown here.  The router is bolted to the top board.  The nail holds the jig to the board below but allows the jig and router to rotate above the board.  By rotating the router, I was able to cut nearly perfect circles.

This photo shows the underside of my jig.  I simply countersunk bolts into the jig and screwed them directly into the router.  To change the radius of my circular cuts I simply drilled multiple nail holes in the jig and moved the nail to the correct hole.  I measured the radius from the edge of the router bit towards the center of the jig.  The edge of the bit that you measure from changes depending on the cut you are making.  For cutting the outside of the circular hoops, measure from the edge of the bit closest to the nail hole.  For cutting the inside of the hoops measure from edge of the router bit that is farthest from the nail hole.

      The jig was nice because it allowed me to make nearly perfect cuts.  I can also save the jig to quickly create parts for a second banjo if I like how this one turns out.  The cuts come out nicer if you make multiple, shallow passes with the router instead of one or two really deep passes.  The exact depth will depend on your specific router and the wood you choose.  Just start shallow and experiment around a little.  It is also important to cut the outside circles first.  This way, when you need to make the inside cut, you can still attach the jig to the center of the circle.  Of course, if you don't have a router or you don't want to make a jig, you could always use a compass (or even a pencil and string) to draw a circle and then just cut it out with a jigsaw or coping saw.

      When you cut the top and bottom pieces of the pot, you can use the router and jig to cut the curved part of the outline, and a saw to cut the straight part.  Sometimes I offset my cuts by 1/16" or 1/32" and then sand the wood down to the final size.  It reduces the risk of accidentally cutting into your piece.  Of course, you could accidentally  sand too far into your piece too, but sanding is easier to control than cutting.

When you cut out the top and bottom pieces of the pot, do not cut a complete circle.  You need to leave a little material for the rectangular shaped part that the neck screws into (see plans).  I'll cut the inner part of the circle out later.

      The plans call for the middle part of the banjo pot to be 1" thick.  I could only find 3/4" thick scrap pine so I had to do a little extra work.  I decided to just cut 2 identical circles and glue them together which resulted in a 1 1/2" thick circle.  After the glue dries, I'll run it through a planer until it is 1" thick.  I am a little worried that the pine won't be strong enough, but I don't want to buy wood for this project so I used it anyway.  When I glued the two circles together, I arranged them so the grains ran perpendicular to each other, just like the alternating plys in plywood.  I think this will make it stronger, but I'm not sure.

Here are my two circles before I glued them together.

Here they are again, now arranged as one unit.  The router really helped to make them uniform, but I'll sand them down to an even closer match later.

Here they are again, glued, clamped and waiting to dry.  Note the wood scraps that I placed between the clamps and the circles.  They prevent the clamps from leaving impressions in the circles.

      That is where I left off today.  It got dark so I cleaned up.  So far I have invested $0 in materials (okay...I did technically pay for the material at one point but it is leftover from other projects so I'm not counting it as a cost) and about 5 hours in time.  I don't think I'm doing a bad job either.  Next time I will sand the parts down, plane the center circle down to 1" and maybe start shaping the neck.  I have some cherry from a friend that I might use fore the neck.  Over the next few weeks I will also be looking for old violin pegs (I might try to make some) and a rabbit, groundhog, cat or goat skin (for the head).  I'll post more when I get the chance to work on it again.

The three pieces that will later form the pot.

Building a Mountain Banjo: Marking the Neck

Here are some basic tools that I used to measure out my neck because I couldn't get a hold of full size plans.  

      Before I could begin measuring out the neck, I head to find suitable material for the neck.  If you look at the profile of the neck on the plans (courtesy of bluestem strings) you will notice that the angled headstock makes it necessary to use a large block of wood if you want to cut the neck from a block of wood rather than joining a headstock onto a smaller piece of wood.  Some people get away with joining a headstock (I myself have used the method to construct a cigar box guitar), but a neck cut out of block of wood is stronger and looks nicer.  That does not mean the block of wood has to be solid.  Roughing out this neck from a block (laminated or solid) of wood requires the block to be at least 25 1/4" long x 2"wide (not accounting for the width of the headstock) x 2"deep (accounting for the angled head stock).  These are the bare minimum measurements with no extra room.  I found it easier to use a 3" x 3" block.  However, a neck is best made out of hardwood, and a 3" x 3" block can be expensive.  So, I laminated 3, 1" x 3" pieces of poplar together to form a block that was 26" x 3" x 3".  All I had to do was cut the poplar to length, dampen the sides to be joined, apply gorilla glue and clamp the pieces tight overnight.  I should also point out that I followed some advice I found on both the Banjo Hangout and the Bluestem Strings websites that said to try and book match the grain.  I'm not sure if I did this correctly, but I'll describe what I did.  I had two slab sawn pieces (quarter sawn would be better but this is a homemade banjo that I'm not investing much money in it) with curves in the grain (when viewed from the end of the board) and one without curves.  I put the one without curves in the middle and laminated the others on the side so their curves were convex to the middle piece.  Hopefully these crude drawings will clarify things.

This is what the grains on a cross section of my wood block look like.  Of course, I exaggerated everything to make it easier to draw.

Here, the cross section of my neck is shown in relation to the cross section of my wood block.

      After the glue dried, I had to mark the block so I could rough cut it.  My local print shop wasn't able to print a full scale version of the plans for me so I resorted to manually making all the measurements rather than tracing the shape of the neck.  It was a little more time consuming, but not too hard.  (Note, I did not use this helpful page because I did not know it existed at the time, but if you are following my steps you may want to check this page out instead.  It should save some time).  First I measured out the total length of the neck being sure to include the little piece of the neck that fits between the top and bottom parts of the pot.  Then I established wear the nut was.  I also drew a center line down the entire length of the block.

This shows the centerline, the edge of what will become the headstock (left line), marks where the nut will be positioned (double lines on the right) and a reference line (tick mark on the right) that would later be used to create the side profile of the neck.

      Using the center line, I measured out the dimensions on the plan.  Not every little measurement is on the plan, but I used some simple arithmetic to figure out most of them.  Also, once you get past the fifth fret on the neck, you can't just divide the width in half to find out how far to measure from the center line.  Past this point, the centerline doesn't actually run down the center of the neck.  I really don't know why I have even been calling it a center line (I could have called it the "fingerboard longitudinal reference line, but that is quite a lot to handle).  However, the total width and the number of pixels (or the distance on your screen if you don't have a pixel counter) are proportional.  So you can solve for the distances using the following formula below where X = the distance from the centerline to the edge of the banjo.  Once you find the distance from the centerline to one edge, it is only a matter of subtracting this from the total width to find the distance from the centerline to the other edge.

(X/Total distance indicated on the plan) = (Pixels from centerline to edge/Pixels from edge to edge)

      I know this looks confusing, but it's really not.  It's just a simple proportion.  You probably learned about them in 6th or 7th grade.  If you don't have a pixel counter, just measure the distance on your computer screen with a ruler.  Be careful not to scratch your screen.  Anyway, it would be much easier to just get full size plans and trace them.  Unfortunately the guy at my local print shop (Pak 'n Fax) tried to print scale drawings for about an hour and then failed.  I wasn't upset until he said it was possible, but it would just take too much time.  He didn't think there would be a net gain for the store, because his wages would not be outweighed by the $3 I would pay.  Unfortunately for the store he failed to consider the possibility of return business which they will not get from me.  Anyway, I am ranting now.  I'll get back on topic.

Measuring the width of the neck.  The distance from the centerline to both edges is equal until you get past the fifth fret (where the bulge in the center of the picture is).  The extra string added at this point changes causes the centerline to not really be in the center.  I really don't know why I have been calling it a centerline.  A square is useful for this step.

      Once you have the top (fingerboard) of the neck marked out you can move on to marking the side profile.  It is pretty easy.  Just measure the appropriate distance from the nut (as indicated on the plans) and then measure the correct depth of the neck at that point.  Make a few of these measurements and then connect the dots.  Again, it would be easier to trace from a full size plan.

I marked the side profile on one side.  It was hard to get an image of the whole profile, but this shows what will later become the angled headstock.  At this point I was really glad that I was cutting the whole neck out of a wood block instead of gluing a separate headstock on.

       At this stage (before you rough cut the neck) I had to decide if I wanted to make a fretless banjo or not.  If I was going to add frets (which I did not) it would have been much easier to measure them and cut slots for them while the edge of my neck block was still square.  I decided not to add frets, but I still took advantage of the square neck blank to measure out where the frets would be and then burn some markers into my neck.  This way, I could still have a fretless instrument but I would have some sort of visual aid to help me get a feel for a fretless instrument.  You can add frets to your banjo if you want, but they require precise measurements from the nut (if I had to guess I would say at least 1/64", but don't quote me on that) and they all need to be level on the plane that is parallel to the fingerboard (or you can get a buzz).  Adding frets is beyond the scope of this article, but there is plenty of other information online.  I didn't want to fret about all the extra trouble, so I just went fretless.

Using a square and a wood burner to put marks instead of frets on the neck.  Doing this step before  rough cutting the neck allowed me to utilize the edge of the wood block and the square.

      There really isn't much to preparing the neck for rough cutting.  It did require a lot of measuring though.  This could be reduced by using this helpful page or just tracing the layout from full size plans.  I have since rough cut my neck and I am now awaiting final shaping.  I'll keep updating as I do more and have time to write.  Oh yeah, I have now spent $17 dollars on my banjo.  I bought screws (used later), poplar, and gorilla glue (which will surely be used for other projects as well).  By the time I finished marking the neck I had probably spent about 5 hours on the banjo, most of which was measuring and re-measuring.  I also met a guy at a bluegrass festival who made his own banjo and has some leftover goat skin.  I think I know what I'll use for my head.

Looking down what will soon be the fingerboard on my banjo neck.

Building a Mountain Banjo: Rough Cutting

      Compared to marking the neck, rough-cutting the neck was a quick process.  The final shaping will be a different story (especially since I don't currently own a draw-knife, block plane, or rasp).

      Like most wood projects, this step could be done entirely with hand tools, but I used a more modern approach.  I really respect the traditionalists who do everything the old-fashioned way, but I want to get this banjo done before the fall hiking season.  So, I used a chop saw and a bandsaw.  If needed, you can go without the chop saw, but it does mike nice, clean, straight cuts.  I used the chop saw to cut the excess material off my neck blank, that is, I cut my neck blank to length.  Next, I used the chop saw to make the angled cut that created the top of the headstock.  See the picture below for clarification.

A side view of my neck blank.  First, I cut on the mark that said "end".  It marked the end of my neck blank.  Next I used the chop saw to cut off the triangular piece that says "cut 2".

      A bandsaw is probably the best tool for the next part.  I was fortunate enough to use Mr. Syzdek's bandsaw.  His wife and son had just finished making him a nice workbench with a nice polyurethane finish.  It was great to have a nice work surface.  I put my blank down on the saw sideways (i.e., what will later be the fingerboard was in a plane parallel to the saw blade) and used the saw to cut the profile of the banjo neck.  With a bandsaw, it is best to cut just outside your mark and then later on you can sand the excess material off.

The profile cut was pretty easy with the bandsaw.  Note the practice pieces above.  Mr. Syzdek suggested I practice on a few scraps of wood.

      Even though the excess material would later be discarded, I held onto to help shape the top profile of the neck and the headstock.  I matched the excess material with my neck blank and taped the two pieces together with masking tape.  That gave me a flat surface opposite to cut on so I could go ahead and shape the top (fingerboard) profile of the neck.  If this sounds confusing, just look at the photos and it should make sense.

The two pieces taped together.  Also some awesome shoes that I got from John D. who in turn got them from his Dad.

A look at the fingerboard side of the blank.  Taping the excess material to the opposite side gave me a flat surface to work with.

      After taping up the blank, I cut the top profile with the bandsaw.  Unlike the side profile, this step required two cuts.  I took extra care where the neck transitions from 5 strings to 4 strings.  Just like the first cut, it was pretty simple.

       That pretty much completes the rough shaping of the neck.  I still have to rough shape the headstock, but I haven't decided what shape I want.  A true Stanley Hicks mountain banjo would probably just have simple curves, but I want to make this banjo my own.  Next I need to use a draw-knife or something to round out the blank.  Then I will use a rasp, file, and sandpaper, in that order, to finish shaping the neck.  The only problems are I don't own a draw-knife or a rasp, and I accidentally left my neck at my parent's place in Florida.  Thus, it will be some time before I can get back to work on my banjo.  It's okay though, I have other things to keep me occupied such as school, making running sandals, and maybe attempting to build a bamboo bicycle.  As always, I'll keep you posted.

More to Come Soon! Last updated 11/30/2012