Shaping Neck

Home Up

Shaping a banjo neck with the usage of hand tools such as rasp, files, surform tools, sanding drums, sanding belts, etc. allows the craftsman quite a bit of latitude and flexibility to get the radius portion of the neck as he or she desires.   There are a variety of neck shapes to suit the individual banjo player with some shaped like a D, Egg or elliptical shape, v shape and a 1/2 radius shape as done with a shaper or carving machine. 

The production environment and the quantity of necks required dictates the type of tooling and machinery used and more and more are going toward the CNC router machines but they are typically slower in production than a double spindle shaper or multiple ganged carving stations.  Either one requires some hand work around the heel and hand volute area to remove additional material.

The shaping of the radius portion of this neck will be about as basic as you can get with hand tools once the bulk is removed at the heel with the band saw.  Back in the 1970s before I had tooling for a double spindle shaper, the radius portion of the neck was rough cut using a special 2 inch diameter by 2 inch length cutter mounted on a horizontal spindle at about 1725 rpm or it could have been 3450 rpm, don't remember.  That particular cutter was used in the textile equipment manufacturing business in Southern Pines, NC to produce wooden shuttles out of dogwood and the teeth on the cutter were ground at a specific angle to prevent tear out and "snatching" the item from your hand.  You could place end grain wood directly against the rotating spindle and it would cut without grabbing it from you.  That was a dangerous operation but as long as you kept your hands away from the rotating cutter, all was well.  I doubt today with all the safety regulations in place, one would be allowed the usage of such a dangerous cutter in a "freehand style" of operation without an overkill of protective guards, etc.  I know it worked and never had a problem with it and can't remember who ended up with the cutter and horizontal motor/shaft. 

Most of my 1970s rasps, files and surform tools are about worn out and should be able to get this one shaped which will take additional time but I am not on a delivery schedule.  One needs a simple fixture or jig to hold and position the neck during the shaping process and I found a piece of Honduras Mahogany that was used on my aluminum bass boat to support the plywood flooring.  That piece of wood has been in my possession for at least 35 years and will work fine although I hate to cut up a piece of wood of that type for a simple fixture but I have no other need for it and have nothing in 8/4 thickness and this piece of Honduras Mahogany has several test holes drilled into it rendering it useless for a banjo neck blank.

Above pixs show the progress of the neck holding fixture.  The notch cut out in the piece of mahogany was used to straddle the center member of the bass boat frame and will work perfect for this fixture with a little modification.  I added a piece of material to one end where the peghead will be clamped in place and the angle is about right for this neck blank.  The wedge could have been made adjustable for other neck peghead angles but a simple padded caul underneath the peghead will work just as well and offer protection to the peghead to prevent marring or denting from clamp pressure.  I pinned and glued the angle/wedge in place and allowed to dry overnight and then traced the profile of a 5-string fingerboard (fret side down) and band sawed to the line.  The fixture will be clamped into a vise and the neck blank will be clamped at the heel end and peghead with padded cauls to prevent marring from the clamps used.  This is about as low tech as you can go but it will work fine!

I have a humongous vise on one of my metal welding tables that I converted for turkey call making and it is entirely too high for holding the above fixture to allow me to shape the back of the banjo neck with hand tools, therefore I ordered a ShopFox Parrot vise since I need another vise anyway and will clamp it to my multipurpose work table which is 10 inch table saw.  While waiting on the vise to arrive, I band sawed the rough side profile of the neck heel and removed as much material as I could to ease up on the hand work with the rasp, file and surform tools.  I marked the width of the heel cap and a line on the end of the heel to give a reference and used the band saw "freehand" style to make the cut.  Pixs below:

Once the vise arrives, I will file the binding and frets before proceeding any further.

I got the little ShopFox Parrot vise in from Grizzly via an Amazon order the other day and mounted it to a portable oak base plate for C clamping to my table saw table which serves as my work bench too....grin if you must!  The Parrot vise is well worth the money but if I were doing instrument repair and building necks on a regular basis, I would seriously consider the guitar makers vise from Stewart MacDonald which cost at least three (3) times as much but in this case, well worth it!  The StewMac vise has several features not available on the Parrot vise.  Also, during the course of shaping the neck with hand tools, I modified/tweaked the neck holding fixture to allow sanding the neck peghead too.  Pixs below:

I removed material from the neck blank using the band saw and to save a little on the hand aka elbow grease power.  If I was in a musical repair environment, I would make the peghead portion of the neck holding jig adjustable to accommodate different peghead angles but this one fits my neck template although not perfect since I used what scrap wood I had on hand. 

After clamping the neck down at the heel and peghead and provided some protection using cardboard as a caul and a piece of heavy leather or thin carpet would work much better.  The second pix of the hand tools I will be using and the Stanley Surform tool was used to remove the bulk of the material and it cuts very fast and aggressive.  The large curved replaceable blade does a great job shaping the sides of the heel.  The second tool is a very rough cut rasp, however I didn't use that tool but a little since it is far too rough for this application and a regular bastard half round medium rasp works much better.  I used the Stanley round surform tool mostly around the peghead hand volute or hand stop area and was invaluable in getting the radius portion of the heel to blend in with the neck.

Shaping this neck brought back a lot of good memories and one that wasn't so good as I remember one of the first necks that I made and ended up wrapping it around the column of my drill press...it was supposed to have been a piece of kiln dried walnut and I got down to the shaping of the neck stage as in this neck and the neck continued to get a back bow in it and that was in the days before the two-way adjustable truss rods.  I vented my frustrations out and literally broke the neck by slamming it hard against the drill press column.  In the future, I took better care in wood selection paying attention to moisture content, etc....grin if you must!

Checking moisture content with a calibrated meter is not a bad idea for musical instrument woods.  Meters are like anything else, most of the time you get what you pay for, but you don't have to break the bank purchasing one and understand a few simple conversions you have to make for different species of woods.  I have purchased turkey box call wood that came in reading 16 to 18 percent moisture and some woods higher of which the seller was truly a "flim flam" artist on EBay!

The above sequence pixs is nothing high tech at all and in fact about as low tech as you can go unless you get out the ole pocket knife and starting whittling instead of using the surform tools and rasps.  I have completed necks before without a good neck holding jig or fixture but it certainly does make it much easier, however once I get to the sanding stage, I will sit down and take a load off my feet whenever I get the chance.   I would use a rocking chair in a heart beat for the sanding stage, however sanding the back of the peghead and keeping it flat works better for me using the neck holding fixture.  The above fixture is multi-purpose and works well for shaping and sanding the neck; just change the style and position of the clamping devices. 

I modified the fixture for better usage with the Parrot vise by routing a 3/16 inch deep mortise into the wood fixture to fit the jaws of the vise which keeps the fixture located in the same position when you release pressure on the jaws allowing the vise to be rotated up to 360 degrees.  I would rather have a feature that allows the vise jaws to remain closed and rotate the base but that is my personal preference.  I reduced the width of the fixture underneath the peghead to allow sanding around the double cut peghead.  I got some hand sanding on the neck with fairly rough sanding paper, 100 grit to remove any tool marks from the rasps and surform tools and will drill the holes in the peghead for the tuners and also the 5th string peg before progressing to fine grades of sand paper. 

I found an old leather belt and made a wooden set of cauls for the Parrot vise and when dry, will sand an angle on the back of the wooden blocks (cauls) to allow for holding a tapered item such as a guitar or banjo neck, etc., Pixs below:

    

The cauls with the curvature against the vise jaws works great and should handle most instrument tapered necks and parallel items as well.  I cut the excess binding off at the nut end of the fingerboard using a small fret saw and thin bladed utility knife that has seen a lot of usage in the past.

PREVIOUS PAGE

NEXT PAGE

BANJO CONSTRUCTION HOME PAGE