Search Results for: Radius

The builds are getting to the point where the ‘boxes’ are getting closed up.  Before I glue on the backs I shellac the inside of the instrument.  Not necessarily traditional, but I started doing it some time ago, and have since found that some luthiers who are much better than me also shellac the inside.  From my wood upbringing I was always taught that one must finish both sides of a piece of wood to balance things.  For an instrument, a coat of shellac should slow down moisture transpiration, which means that changes in humidity around the instrument will not result in as quick expansion/contraction of the wood, which should increase the stability of the instrument.  The inside of the back is also shellaced, all except where it will be glued down.

Once the back is glued on, I sand the sides to get them nice and flat and to make the edges of the top and back flush with the sides.   I do this before doing the binding since when the binding channel is cut the router bearing is traveling along the side, so if the side is a little out-of-whack the binding channel will be a little out-of-whack.   To sand the sides (and do other operations) I use a bit of a bench-side clamp I made out of some boards, bolts, and knobs.  I bring it out and clamp it to the bench when I need it, and otherwise it does not take up bench space.  The inside of the ‘jaws’ are cork lined, with one side being just a cork perimeter to allow clamping of the radiused back.  Makes work on those pesky curved sides very easy and stable.

I currently make fingerboards with a 12 inch radius, which is somewhat subtle. I have designed a radius cutting jig so that cutting alternate radii is not a big issue. It might be good to have in my ‘toolbox’ as it were the setup for a 10 inch radius or even a 9 inch radius. Might be interesting to see what these more curved fingerboards feel like, but I am not a player, so am not really one to judge.   So …

I have cooked up a little test ‘instrument’ (the world’s worst ukulele!) that has interchangeable fingerboards with different radii.  (7, 9 10, 12)   The test platform is based on a concert sized ukulele, and the fingerboard has only 5 frets, but I figure that should give one some feeling for noting and playing bar chords.

To use it you slack the strings, lift the existing fingerboard, put on another, and tune up the strings.  The fingerboards fit over two small placement pins placed in the neck. The nut end of the fingerboard is held down by the string pressure over the zero fret, and the bottom end is held down by a single bolt and wing-nut.  I have sent this out to a customer for his feedback, and have another who is interested.  I’ll be interested to see if anyone finds a big difference.  I find that the different radii make little difference, but again, I’m not a player.   Since you are a dedicated reader of this blog,  if anyone else is interested in this experiment, send me some e-mail, and I can send the test “ukulele” out when the first two experiments are done.

I am back up north in Pennsylvania after a winter sojourn in Florida and starting on the next set of 4.  It will be an interesting set.  3 of the 4 are special orders, each of which has some different aspects which will be fun.   The three are:

1) A parlor guitar in black walnut and redwood.   Maybe some custom pearl inlay, still in discussion.

2) A short scale Guitalele.  Baritone body in sycamore and Pennsylvania red cedar top, 19 inch scale, 6 string neck, Picasso headplate, side sound port, radiused fingerboard.

3) A tenor in spalted sycamore with a curly redwood top and somewhat extensive custom pearl inlay.   Some new things here that should be interesting to work out.

The fourth instrument will be a concert, on which I want to conduct some experiments with some new build procedures.  Have not decided on the wood just yet.   I’m leaning to some local curly maple I cut a while back and a redwood top but I might go casuarina back and sides.

In all of this it is fun to go through the wood pile to pick out parts, and discover things you have forgotten about.    Wood is wonderful stuff!

The latest set of four is really good.  The best set I have made to date.  They all sound great.  Two of them, the walnut & redwood kasha and the ambrosia silver maple & redwood are already spoken for, but it is hard to let them go.  A mother hen likes to keep the new chicks close.

All the instruments in this set involve two new structural elements.   They all have radiused fingerboards and side sound ports.  A radiused fingerboard is supposed to make playing, particularly the playing of barre chords, easier since a slightly rounded fingerboard cross section mirrors the shape of a finger.  Not being a player, I can not really comment on this, but on the small scale of a ukulele I kind of have to question whether it really makes much of a difference.  A radiused fingerboard does complicate the build process however.

A side sound port is designed to project more sound up to the player.  I was a bit skeptical, but with these four there is a really noticeable difference in the sound between having the sound port open, and covering it with your hand.  A sound port seems to make the instrument sound more lively and also seems to increase the volume.  They seem to add a lot and are not that difficult construction-wise once I got things worked out.

For most of what I build these days the back and sides started with me and a chain saw, along with fingerboard and bridge material. Bold items below started with me and a chain saw or at least started with rough boards from a local source.

The latest four, from left to right:
Kasha tenor – Port Orford Cedar top, sycamore back & sides, koa binding, radiused Florida black olive fingerboard & bridge, koa headplate, side sound port.

Kasha tenor -recycled redwood top, black walnut back & sides, sycamore binding, radiused casuarina fingerboard, bridge & headplate, side sound port.

Tenor – recycled redwood top, ambrosia curly silver maple back & sides, ancient bog oak binding, radiused Richlite fingerboard, ebony bridge & headplate, side sound port.

Tenor – Pennsylvania red cedar top, curly ash back & sides, east indian rosewood binding, radiused bocote fingerboard, bridge & headplate, side sound port.

[Note: the blog pages show pictures in a reduced ‘fuzzy’ way.  Click on the picture to see the real thing.  This applies to any picture in this blog.]

No, this is not Italian opera.

The next group of four, all tenors, is coming along. Two have a more ‘standard’ bracing, with a slight modification this time, and two use the Kasha style of bracing. They are all different combinations of woods, which is pretty exciting to see coming along.  I love wood!  The bodies, from left to right, are black walnut & redwood, sycamore & Port Orford cedar, ambrosia curly silver maple & redwood, curly ash & Pennsylvania red cedar.  Then there are the interesting features, like my first use of 2000-4000 year old bog oak for black bindings.

All have side sound ports, and will have radiused fingerboards since I have had a number of requests for these features, and I need to learn how to make them.  I made a jig to cut oval side sound ports, and figured out a process to add binding around the edge of the sound port, to make it look nice and trimmed.  Things are to the point of the first coat of sealer on the tops, and the rough sanding of the bodes is done on two out of the four.  (I get to take a break from sanding to write this blog.)

Just waiting are the other bites of wood.  Fingerboards, bridges, headplates and heelplates

Because I have had a number of requests for them, and because I should know how to build them, the next set all will have radiused fingerboards and side sound ports.  I built a new jig to slot fingerboards which does a very nice job on a radiused fingerboard (and a flat fingerboard.)  It is easy to cut a hole for the side sound ports.  I made a jig which clamps on the sides, and then there is a router follower that goes around an oval hole.  The harder part is figuring out how one binds the side of the hole, so there is no end-grain of the side showing, and so it looks nice.   After a number of tests/trials, I think I have this pretty well figured out.