I recently saw a very simple design for a stand for a
I could make one in a flash as it is essentially a plywood
box, about 20" X 14" X 8", with a padded hole in the top in
which the banjo rests (with its neck going up and slightly
The problem is that I can't come up with a good way to
determine the proper shape of the hole.
It is a moderately complex shape in that it must accommodate
the curve of the resonator, and the varying diameters of the
instrument itself. Also, the instrument is rather fragile so
doing things like dragging a divider along its surface would
What might be some ways (other than running it through my
table saw) that I could get a reasonably accurate "tracing"
if the banjo, about 6" from its tailpiece?
Sincere thanks for any help,
Have a digital camera? Place the banjo on a contrasting surface, with
a yardstick or tape measure next to it. Light the banjo and make
pictures from directly overhead.
Edit the image in any photo software and fill the area around the
banjo with black. Enlarge the image to full size and you have a
On Fri, 25 Jan 2008 20:03:04 -0500, Kenneth
I thank you for your interesting suggestion, but if I am
understanding you correctly, there would be a difficulty:
I need to get the shape of the instrument's cross-section
about 6" from the tailpiece end rather than an outline of
the instrument at its widest point.
How could the photo approach you suggest do that?
I suggest that you use a standard carpente's pencil. Lay the banjo on
a suitable size piece of craft paper (the plain brown stuff butchers
use). Place the flat side of the pencil next to the banjo and trace
the outlne. You will end up with an outlne that is 0.250 wider than
the banjo. The rest depends on the tools you have. Post a bit more
detail and I will be glad to offer a suggestion.
If I were trying to make an outline of the whole instrument,
the suggestion you offer would be perfect, but...
I need to get the outline "part way up" rather than the
Here's a link to the design I want to copy:
and when you take a look, I suspect you will see the problem
with typical tracing methods.
Sincere thanks for your ideas,
Cut a piece of scrap plywood with a cutout that the banjo can easily
pass through past your intended cross section line - leave about 1/2"
clearance between the banjo and the wood. Then prop up the banjo
vertically, slide the bottom of the banjo into the plywood cutout, and
prop up the plywood until it is horizontal at the desired level. Then
use a compass set at 1" to trace the perimeter of the banjo. The
compass points must be perpendicular to the banjo outline at all times
as you run it around the perimeter. Remove the banjo, place a piece
of tracing paper over the plywood and trace the perimeter line you
marked with the compass. Then using the compass on the same setting
(don't change it between steps), trace 1" inside the marked perimeter
to find the exact perimeter. That will create an exact fit, depending
on your skill and tool sets - how much clearance you need is up to
you. I'd probably leave about 1/8" clearance and taper the hole to
make banjo insertion easier.
As an alternative, you could wrap the banjo base in a layer of paper,
then a layer of plastic, tape it up tight, make a box form (could be
the holder's side walls depending on what finish) of the desired size,
prop up the banjo vertically in the box, then use a can of low-
expanding spray foam to fill in the box around the wrapped banjo. Now
you can use the foam, cut as required, to create an exact template of
whatever section you need, or keep it as the banjo box liner and just
make a top piece of wood to fit.
Cheap and dirty way, cardboard, scissors, and tape, keep hacking until
you've got the right shape.
Not quite so cheap or dirty, contour gage.
http://grizzly.com/products/10-Plastic-Contour-Gauge/H7378 Note that
I'm suggesting the plastic one rather than the metal one since you
said that the instrument was fragile and I figure the plastic is
slightly less likely to mar anything than is the metal one.
The way a draftsman would do it--set up a reference surface and
measure at points from that surface. A draftsman would use a surface
block and inside caliper most likely, but since you don't have those,
a practical way to do this cheap with minimal risk of marring the
banjo--joint a three foot 2x4 and sand a dime-store plastic ruler to a
point, then measure with the point touching the banjo (don't drag it,
just touch, write down the measurement, move it a quarter inch,
repeat) with the 2x4 far enough back that you still have numbers on
High tech, fancy, and fanciful--get a line laser level (the kind that
projects a line on all the walls of a room). Set it so that the line
crosses the banjo at an appropriate point. Take a photo from the end
(use a slow shutter speed), you'll have part of the contour. Rotate
the banjo and repeat until you've got it all. Make sure you have a
ruler in the photo for a dimensional reference.
A possibility would be:
1. Place the banjo body in a plastic garbage bag to protect the
2. Appropriately position the body of the instrument is a properly sized
box using styrofoam spacers.
3. Use an expanding foam to fill the box making a mold of the body to
the required depth/height.
Hi Jack (and others),
I am moving in the expanding foam direction because it would
provide excellent support for the instrument, but I do need
a bit of education:
What kind of foam do I want for this sort of thing?
The only foam I know at all is the "hardware store aerosol
Is there another sort of foam better for this purpose?
Make sure you get one that is NON expanding or minimum expanding.
It will say something like being used for windows and doors. The
regular triple expanding stuff could do harm as it generates quite
a bit of pressure.
Keep the whole world singing . . . .
I agree with Dan that a minimum expanding foam would be best. "Great
Stuff" now makes an aerosol that is designed for use in foaming around
windows to prevent bowing the casement. I'd probably also use a
cardboard box as it would allow sidewall flex minimizing pressure on the
The stuff they sell at the borg is OK for insulation, but lousy for this
Do a Google for "urethane foam".
You want the 2 pound stuff.
It is sold as a two (2) part kit and can be shipped UPS.
It will stick to anything so use a parting agent such as clear packing tape,
plastic foam, etc.
Last time I used some, got it from an outfit in West Palm Beach, Fl and I'm
It was still my lowest cost supplier.
You may want to be careful with foam unless you have some type of
material between the instrument and the foam. It may be possible that
the foam could react with the various finishes on the instrument.
Any reason a regular contour gauge won't work? Obviously not all at
once, but you should be able to capture the shape of the instrument in a
remove no.spam. to email
A contour copier would work. A plastic one should not mar
I have had good luck just taking a piece of poster board type
cardboard, making a few cuts with scissors, trial and error.
Might take 3 attempts to get what you want.
Keep the whole world singing . . . .
6" from the tailpiece would be through the pot. Scribe it
with a carpenter's pencil held flat, with a sheet of paper
held over the resonator to protect the finish. The radius
is huge, so a 3/16" difference won't be noticeable. You'll
have padding to fill the gap, anyway.
To get the neck contour, pack plasticine clay around
the desired section, again with a sheet of paper in
between to protect the finish.
On Sat, 26 Jan 2008 14:34:32 -0800 (PST), Father Haskell
You might want to take a look at the link I posted earlier
in the thread:
As you will see, there is no involvement with the neck, just
the tailpiece end of the instrument.
All the best,
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