SIMPLE 5-STRING FRETLESS BANJO
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NOTE: 15 additional photos
and a sound sample of this instrument are available. Click
here for information.
This evolved out of the 3-string banjo described elsewhere in this
webpage & has proven a very decent sounding & playing instrument.
One weekend of tinkering should be all the time needed to
completely build the thing. Zero special skills & no power tools
are necessary. Very little, if anything, is critical. Obviously
this isn't a fancy instrument, but is very much fun to play. With
all new parts the price should be in the neighborhood of $10 - $15.
Brief description of the instrument (more detailed info follows):
- Two circles of regular 3/4" pine, with a large hole cut in the
middle of each are screwed together to make the banjo body.
- Cut a 9" diameter piece from an old broken "fiberskin" or other
synthetic drum-head, which can be obtained, usually for the
asking, from school music departments & sew this onto a 7"
diameter wire ring (available at hobby stores, from an old
lampshade or simply soldered together from a coathanger) to make
the "skin" head.
- The rim, over which the skin/hoop affair is tensioned is simply
the top 5/8" cut from a 6" diameter tin coffee can & placed atop
the wooden body.
- Large-headed flat-top sheet-metal screws, with a 3/8"washer on
each, positioned evenly around the skin/hoop serve to simply but
very adequately tension the head to the desired tightness.
- The neck is extremely simple - just a plain piece of 3/4"
straight pine (hardwood will work as well of course, but pine
works perfectly). A half year's playing now show no signs at all
of the strings (even the wound one) "denting" or "grooving" the
pine fingerboard. The high-end of the neck is screwed securely
to a lower neck-extension (see illustration elsewhere in these
instructions to get a better idea what I mean by "neck
extension") that goes through a rectangular slot cut into the
body's side and fastens into a notch or channel cut into the
tailpice part of the body. To understand this another way, the
neck/neck extension is held & secured very solidly in these
slots and notches when the two halfs of the body are screwed
together.I like my banjo necks short and this design reflects
this preference. You may certainly make the length whatever you
desire - no complications or problems should arise by altering
neck length. A longer neck may require different gauge strings.
- Inexpensive tuning gears are mounted to the non-angled tuning
head. Small brads very effectively keep the strings properly
spaced and properly low enough where they ride over the nut.
- A conventional 5th string arrangement is not used -- instead, a
tuning gear for the 5th string is mounted at the head & a very
simple and effective "two-brad" affair is used at the 5th "fret"
to shorten the 5th string. I really like this foolproof system.
- Strings are 4/5 nylon fishing line & 1/5 banjo string.
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DETAILS AND DIMENSIONS:
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CLICK HERE FOR ADDITIONAL ILLUSTRATIONS
BODY - Made from regular 3/4" thick shelving type pine: - Make two 8-1/2" diameter disks - In the center of each disk, cut 5-1/4" diameter holes. Make a 1/2 " deep by 1-3/8" wide channel in the inside of the TOP body half (these channels form-fit & hold the neck extension in place securely) located like so: Then make a 2nd channel, located as shown below (make this channel the same PS - although printers width and depth as the & monitors might not 1st, but 13/16" long). show it as such - _ _ _ _ _ _ Make the depths this is supposed / \ in this top half to be ROUND.... / \ as close to that / \ specified as is / . - - - . \ possible. The / / \ \ depths here | / \ | determine the |********/ \***** | angle of the | 1st | 2nd | * | finished neck. |channel| channel| * | |********\ /**** | | \ / | \ \ / , \ ` - - - ' / \ / \ / \ / \ _ _ _ _ _ _ _ / - Next, the inside of the BOTTOM body half receives similar treatment, except make the first channel depth 1/4" deep and the 2nd channel depth 1/4" deep also. Make this 2nd channel 13/16" long. As you cut these channels in the bottom body half, "trial mate" the two body halfs together with the neck extension fitting into the channeled parts. Cut & fit the the channels carefully so that the extension JUST fits snugly into the channels when the two body halves are brought together. Do most of the "fitting" on the BOTTOM body half as the depth of the top body half's channels determine the finished neck angle and are a bit critical. (Not to worry much though - as shims or additional whittling here can work wonders). ******************************************************************* NECK AND NECK EXTENSION - I prefer to use straight pine: General concept & dimensions - not necessarily to scale: | | |/________________ 18-3/4" ________________\| |\ /| | | | | |/___________ 14-1/4"___________\| this extension goes | |\ /| thru the "rectangle" | tuners | | in the body sides & _[]_[]_[]_.________________________________ it's end rests in a | == == == side view of neck | notch near tailpiece |___________________________________________|_________________ | neck extension | | | |_________________________| | | screwed to neck | | securely with 4 hefty wood- | | | screws (from underside) | | | | | | | | |/____________ 22-3/4" end to nut ________________\| | |\ /| | | |/__________________ 27"_____________________________________\| |\ /| I make my neck 18-3/4"" long (minus the neck extension) , 1-3/4" wide and 3/4" thick. String-length on my instrument is 19-1/2", nut to bridge. Make the neck extension 10-3/8" long, 1-3/8" wide and 3/4" thick Use a raspy file to round-off the bottom-side of the neck. I find it's not necessary to severely round off the neck-bottom -- just break the edges nicely with perhaps a 1/4" radius or thereabouts. Do not round off the neck in the area where it will attach to the neck extension. Here's how the neck, neck extension & banjo body go together. tuners _[]_[]_[]_.________________________________ top body half | == == == side view of neck |____________________ |___________________________________________|................. | | |_________________:__| |_______|.................: | extension |____________________| bottom body half (screwed to the top half from the bottom using four hefty wood screws) If the channels or notches in the body halves are made properly, no glue or fastening devices will be needed when securing the neck assembly to the body. The pinching action of the two halves of the body will hold the neck in securely & once the two halves are screwed completely together. ******************************************************************* Sewing the "skin" onto the wire ring: This part lends itself better to a written description rather than to ascii drawings. Fortunately, it's not difficult to accomplish and is easy to describe. As mentioned above, school music departments generally have broken or old drum-heads that can be begged easily. Failing this, these heads cost little new from musical supply houses/catalogs. - Cut the "skin" an inch or so bigger in diameter than the wire ring. - Lay the "skin" on the ring & start folding it over the ring -- securing with spring-type clothespins as you go along. Keep the clothespins as close to each other as possible. Keep the "skin" stretched as tightly as possible. When all the skin has been folded over & you have a zillion clothespins on the affair, even then tug at the "skin" edges with a pair of needle-nose pliers to try to get it tighter. - Using a couple yards of waxed dental floss, remove a clothespin or two & start stitching the "skin" onto the ring. Push the needle thru the two layers of the "skin" as close to the wire ring as possible, then loop the thread around the ring's outside & back thru the two thicknesses of "skin" again. Keep the successive stitches about 1/8" apart. Go around the entire ring this way, occasionally retightening the "skin" & removing clothespins as necessary. - When done sewing, work Elmers or Titebond glue in all along the floss stitching. Using this method, I have never had a stitch or head failure. ******************************************************************* Mounting and tensioning the "skin" head: - First cut the top 5/8" off the top of a 6" diameter tin can (creating a 5/8" tall by 6" diameter metal "rim"). De-burr the cut edge a bit, re-round this rim and carefully center it (cut side towards the wood) on the top of the banjo's faceplate. Then carefully center the "skin"/ring affair over the tin can band. - The 1-1/4" long or so flatheaded sheet-metal screws (& associated 3/8" diameter washers) which tension the head must be located as very close to the edge of the "skin" head/wire ring as possible. Space these screws out evenly, putting no screw in the area where the strings will pass over. - Begin tensioning by tightening the screws against the wire ring evenly. Tighten one screw (not super tight) then tighten the one 180 degrees opposite it. work around the entire head this way. I try to tension the head just so it has a nice "ring" to it - don't over-tighten. Details of how one of the 15 large sheet-metal screws placed at regular intervals around the head pulls down on the "skin" head's wire ring & thus tensions the membrane:
CLICK HERE FOR ANOTHER ILLUSTRATION OF THIS.
Screwheads This is an enlarged view. pull down on wire ring to tension. _ s_ k_ i_ n_ ___ / || This tensioning /_____\ / || method is a bit 3/8" D. Washer | | o || 5/8" x 6" D. crude, but works |/| wire || metal "rim" very nicely and Sheet-metal screw |/| ring || reliably. I was |/| || originally plan- __________________|/|_______||____________ ning a wooden | :/: tensioning ring, | :/: but this "screw" | Banjo body :/: method worked so | (top half) :/: nicely I aban- | :/: doned that plan. |------------------:/:--------------------- | :/: | : | Banjo body | (bottom half) |__________________________________________ LATE NOTE (ABOUT THREE YEARS LATER): This "too simple" banjo head method has proven foolproof -- here it is years later and I never even had to tighten a single "head-tightening screws". The head remains as taut as when it was made. D.H. 2/14/2001 ******************************************************************* Tuning head, nut, etc details:
CLICK HERE FOR AN ADDITIONAL ILLUSTRATION
This illustration shows how 1/2" flat-headed brads (o) are used to "push-down, & position strings and to "fret" the 5th string at the 5th "fret". Nothing is to scale here - this is just to illustrate the general concept. In actuality, the brads for the 5th string are only offset about 1/16" and each set of these brads are about 1/2" apart, right to left. The brads just to the left of the nut are located about 3/16" from it. Remember - these brads not only create the necessary string offset, but they determine the proper string spacing, so be careful in placing them. They also assure that the strings are pushed down low enough to ride solidly over the nut (when tapped in, make sure that the brads aren't driven so far down that the string is pinched -- just lightly touching the string is what's desired. The nut is easily made by installing a guitar-type fret here. In lieu of this fret, a channel can be grooved and a length of big paper-clip size wire cut and glued into this channel will work nicely. Enlarged & not necessarily to scale --- o = head of brad. 0 = tuning pin ,,,, = strings For sake of simplicity, only the 2nd & 5th string are shown here ___ ___ | | ___|_____|_____________________________________________________ | | | 0 0 |nut | ' , | | ' , | 2nd string | ' o,| , , , , , , , , , , , | | | | | | | | | | | | | 0 0 0'''''''o, | 5th string ,o''' | 'o,|,,,,,,,,,,,,,,,,,,,,,,,,,,o,' |____________________________|__________________________________ | | | | | | Note: It is occasionally necessary to use ~~~ ~~~ ~~~ 2 brads (as with the left end of the 5th string here) if the angle, when using just one brad, is insufficient. ******************************************************************* Bridge details: Made of any scrap of 1/8" thick wood. I used hardwood here. Dimensions are 1/8" thick by 2 3/8" wide by approximately 3/8" tall. Make the bridge taller than it needs to be, as some string action experimentation will be likely called for. I like to make the grooves in the bridge fairly deep -- 3/32" or so -- so the strings aren't as likely to pop out of the grooves. The bridge is just a rectangular slab of wood with no feet etc -- just sand any sharp edges where one's hand might hit. It's normal to make the bridge grooves so strings run parallel down the neck, but I prefer a bit wider spacing at the bridge than at the nut & I space it out a bit more there. ******************************************************************* Comments on tailpiece & details of construction: I find that the strings shouldn't ride over a banjo's bridge at too much of an angle. The desirable angle is JUST so there's enough downward pressure on the bridge so the strings don't buzz. Much more pressure and the bridge can dig into the skin head to an unnecessary degree. __ Width / o / 1-1/2" / o / | Make from a 1/16" - 3/32" thick piece / o / | of steel. It needs to be this thick Heigth / o / | because so much of the tailpiece about /_o / | stands above the wooden rim. 1-1/2"* | / | O / Make this hole elongated - this Slightly bend | / allows for adjsutment up and down to tailpiece bot- | / alter the angle of strings over bridge. tom to follow | / curve of the This tailpiece mounts securely to the wooden banjo body body with one hefty wood-screw. * I did not give exact dimensions for the heigth of this tailpiece as it's better to determine this by referring to your own instrument. ******************************************************************* Strings I use: 1st - .040 clear nylon fishing line 2nd - .040 clear nylon fishing line 3rd - .050 day-glow yellow K-Mart brand (Shakespear) weed-whip line 4th - .034 wound, nylon-core banjo string 5th - .040 clear nylon fishing line The above configuration gives a very nice mellow tone. ******************************************************************* Click here to access my webpage. Dennis Havlena - W8MI Mackinac Straits northern Michigan
