Some notes on the hurdy-gurdy plans and instructions in Making and Playing Musical Instruments by Jack Botermans, Herman Dewit, and Hans Goddefroy. Text is by Afke den Boer and Margot de Zeeuw, translated from Dutch by Anthony Burrett, published 1989 by University of Washington Press, Seattle WA, ISBN 0-295-96948-2. Revised January 21, 1998
As of July 1996, the book is out of print, and the UW Press has no plans for reprinting.
There is a new section, What's New , at the end of the document. Have a look there to see what changes I've made in the instructions.
I have written these notes to help people who want to build a hurdy-gurdy from the plans in this book, which has the most complete set of instructions I know of. As with any instrument plans, there are some good points and some bad points in the author's instructions. My intent is both to correct some of the errors I have found in the plans and to provide some insights into our hurdy-gurdy building philosophy. I will caution you that I have not yet made an instrument from these plans, though I hope to do so in the future. I welcome and strongly encourage any feedback you can provide about these notes. Your candid advice can help me improve them so that the next person will have an easier time.
Please remember that these notes are intended to accompany the book. If you don't have the book, a lot of what I've written won't make much sense, if any at all. It's relatively new, and should be available by Interlibrary Loan or from abebooks.com..
These notes are distributed free of charge and are not to be sold under any circumstances.
Any woodworking or metalworking project involves some potential dangers, even if you're using hand tools. You are responsible for maintaining safe shop practices, and we are not liable for any injury you may incur as the result of following these procedures. Please remember to work patiently and carefully, while taking measures to protect your eyesight, hearing, lungs, and fingers.
We assume that you have some woodworking experience, preferably making a stringed instrument. This is a big project, and it's very time-consuming and exacting work. You will need patience, perseverance, and a willingness to remake a part if it doesn't work right. Don't hurry. We're glad to help as much as we can: we built our first instrument from a kit with very little guidance or experience and very few tools, so we remember what it's like. If you get stuck or the plans aren't clear, call us or write us and we'll try to assist you. Building an instrument of this complexity is very satisfying when it works, but extremely frustrating when it doesn't.
It's very important to read the entire set of instructions and these notes several times before you start cutting. Have a clear picture in your mind of how the parts relate to each other and what they do. Some of the parts need to be made in a different order than the authors suggest so they can be fitted correctly.
We strongly recommend obtaining Destrem and Heideman's book on hurdy-gurdy adjustment and maintenance. It's in English, French and German, and it gives a great amount of useful information about shaft and wheel mechanics, tangents, dogs, cranks, and more. Another useful resource is the hurdy-gurdy method book by Doreen Muskett , which gives some setup information and a method for learning to play. These books are available from Dusty Strings in Seattle. We also have a DVD that shows instrument maintenance techniques and troubleshooting.
We use inches for most dimensions, while the dimensions in the book are metric. I'd leave it that way, except that the North Americans will have a lot more trouble finding metric drills, metric router bits, and metric dowels. In addition, our metalworking tools are all in inches, so the shaft and bearings and wheel are in inches. I converted the rest to keep it consistent. There are lots of holes and grooves and slots that need to be redimensioned to account for the changes in stock thickness. Be sure of your part dimensions before you start cutting. You will find occasional metric dimensions given in the notes.
If you're in a metric country, you should have less trouble, but you'll be annoyed to note that some of my dimensions are different, so you'll have to convert the Bill of Materials anyway. I originally wrote this document for a North American audience, not expecting that I would put it on the Web for the whole world to look at. 1.00" = 25.4 mm.
The authors suggest walnut for most of the parts, which is an excellent choice with a few drawbacks. Walnut works well, but it needs to be filled if you want a smooth glossy finish, and working with it bothers some people's respiratory tracts. Western bigleaf maple is a good alternative. It finishes nicely, but is a little harder to work with and is also harder to bend. Other woods may be used as well, but try to avoid anything really exotic: this instrument is hard enough to make without introducing the uncertainties of an uncommon material. There are a few places like the handle where an exotic wood can be used with no problem.
Dimensions are given in inches except as noted. Please note that these are not the final dimensions in all cases.
|Back panel||walnut||12 x 5-1/8 x 1-3/8||1 piece|
|Side panels||walnut||24 x 10-1/4 x 1/8||1 piece|
|OR 28-1/2 x 7 x 1/8||1 piece|
|OR 24 x 5 x 1/8||2 pieces|
|Linings||walnut||18-1/2 x 5/16 x 5/32||4 pieces|
|Front panel||walnut||4-3/4 x 6 x 5/16||1 piece|
|Tuning pin box||walnut||5 x 6-3/8 x 1/2||1 piece|
|Tuning pins||5 commercial cello pins, or make your own from well-seasoned walnut, maple, ebony, boxwood, cornelwood or other fine-grained hardwood.|
|Front panel strips||walnut||4 x 3/32 x 1/8||2 pieces|
|Base||walnut||21-1/4 x 6-1/4 x 1/8||2 pieces bookmatched|
|Base center strip||walnut||4 x 5/8 x 1/8||5 pieces, note unusual grain direction|
|Ribs||walnut or spruce||Rib A: 11 x 1-1/2 x 1||1 piece|
|Rib B: 10 x 1-1/2 x 1||1 piece|
|Rib C: 8 x 7/8 x 1||1 piece|
|Rib D: 6-1/2 x 5/8 x 3/8||1 piece|
|Shaft||5/16" drill rod W-1||12" long||1 piece|
|5/8" CRS round||2" long||1 piece|
|3/32" brass or steel||6" long||1 piece|
|Handle||maple, ebony, exotic hardwood (not cocobolo - some people have skin allergy to it)||3 x 2 x 2||1 piece|
|Crank||brass bar stock||3-1/2 x 1 x 3/16||1 piece|
|Handle shaft||1/4" drill rod W-1||3" long||1 piece|
|Bearings||3/4" black Delrin rod||6"||1 piece|
|Oil sleeve (optional)||3/16" stainless steel suggested||1"||1 piece|
|Wheel||1/2" Baltic Birch ply||7-1/2 x 7-1/2||1 piece|
|3/4" black or natural Delrin rod||3"||(if wheel insert is used)|
|walnut facing||7-1/2 x 7-1/2 x 5/32||2 pieces (other woods may be used for this facing)|
|Flange (if wheel insert is not used)||1" CRS round||2" long||1 piece|
|#2 x 1/2 or #2 x 5/8 wood screws||brass, Philips||3 pieces|
|Soundposts||1/4" maple or oak dowel||15"||1 piece|
|Tangent box (keybox sides)||walnut, pear, plum, maple, quartersawn and seasoned wood is greatly preferred for this part.||12 x 5-3/8 x 1/4||1 piece|
|OR 12 x 3 x 1/4||2 pieces|
|Keybox shelf||same as keybox sides, or maple||2-1/2 x 1-1/4 x 1/4||1 piece|
|Keybox end block||same as keybox sides,||2-3/4 x 2-1/2 x 1/2||1 piece|
|Keybox top||walnut, maple, dry exotic wood (not cocobolo)||12 x 3 x 5/16||1 piece|
|Key shafts||maple, boxwood, ebony, holly, cornelwood||3-3/4 x 9/32 x 3/16||21 pieces|
|Key fronts||as for key shafts||11 x 19/32 x 3/8||1 piece|
|11 x 9/32 x 7/8||1 piece|
|Tangents||hard rock maple||dimensions for stock: at least 36 x 3/8 x 5/32 (make extra - can be in shorter pieces)|
|Tailpiece||walnut||1 x 2 x 5||1 piece|
|Chanter bridge||maple||3-1/4 x 2-5/8 x 1/2||1 piece|
|Trompette and bourdon bridge||maple||1-5/8 x 1-1/4 x 1/2||2 piece|
|Trompette rest||ebony, taqua, maple||3/8 x 3/8 x 1-1/2||1 piece|
|Wheel Cover blocks||walnut||1/2 x 1/2 x 2||2 pieces|
|Wheel cover||walnut||12 x 3-1/4 x 5/64||1 piece|
|Chanter nuts||maple||1 x 3/8 x 3/8||2 pieces|
|Violin tailpiece adjuster||You can buy this at a violin shop. Sacconi brand is our favorite.|
|Trompette adjustment peg||Buy a violin peg, or make your own from well-seasoned walnut, maple, ebony, boxwood or cornelwood|
|Tourne-a-gauche||turned from hardwood, or made from 1" maple or other hardwood dowel.|
|Soundboard||spruce guitar soundboard, or walnut, mahogony, or maple (cedar is not recommended)||21 x 6-3/8 x thickness (below)||2 pieces bookmatched|
We measure soundboard thickness in millimeters. All soundboards are not the same thickness; they can vary considerably, depending on the type of wood and its stiffness. Walnut or maple soundboards should measure 2.0-2.5 mm, spruce should be 3. 5-4.0 mm.
If you have trouble finding supplies, we can sell you some of these items, including strings, dog blanks, brass stock for the crank, tailpiece adjusters, cotton and rosin.
|Their term||Our term|
|back panel||tail panel or tail block|
|front panel||head panel or head block|
|bottom (base) panel||back|
|upper panel||soundboard or top|
|tuning pin box||peghead|
|tuning pin||tuning peg|
|axis||shaft or axle|
|screw assembly||tail bearing|
|handle||crank (sometimes), handle (sometimes)|
|tangent box front panel||keybox shelf|
|tangent box back panel||keybox end block|
|tangent box lid||keybox top or keybox cover|
|key strips||key shafts|
|keyboard strips||key fronts|
|travel pin for trumpet string||trompette rest peg|
|support strips for cap||wheel cover blocks|
|trumpet bridge||dog, dog bridge, chien|
|thin bourdon||petit bourdon (string)|
|thick bourdon||gros bourdon (string)|
|trumpet string tuning key||trompette adjustment peg|
|bridge for melody strings||chanter bridge|
The authors maintain that the finish can be removed from an area so a part can be glued there. We tried this once with poor results, so we suggest placing masks on the soundboard for the parts that are finished separately and glued on later.
These are shown on p.8, where they call the reamer a "conical gouge" and the peg shaper a "sharpener". They aren't cheap, especially the cello tools, and they are not interchangeable because they have different tapers and sizes. One option is to buy them. Another is to find someone who makes violins and cellos who will let you use their tools. You won't need them for very long, and you can take your instrument-in-progress to their workshop and do all the work in one session. Professional violinmakers are sometimes touchy about lending their tools, so you may do better to find an amateur. A third option is to make all the pegs on a metal lathe, using the compound slide to cut the taper. In this case you will only need the violin peg reamer, but you need to match the taper very carefully. If you buy or borrow a peg shaper, make sure it is adjusted to match the taper of your reamer.
If you buy cello pegs you'll need the cello reamer, and you'll probably need the peg shaper to get them properly rounded. H.S. Wake discusses some peg shaper options in The Technique of Violin Making.
I could make list of the tools we use for building instruments, but it would be too long. We assume that you have the standard complement of saws, squares (a set of engineer's squares is really useful), rules, planes, chisels, vise, drill, etc. A violinmakers knife is very handy, as is a set of needle files and a variety of other files (flat, square, triangular, round, curved). You'll need a brace and bit, with a 10+" long 5/8" auger bit for it, and a 5/16-18 H1 spiral point tap (you'll need a new one even if you already have one, because you're going to grind off part of it), a 5/16-18 H1 bottoming tap, a 0.3125 straight flute chucking reamer, and a 0.2510 straight flute chucking reamer.
The most useful tool in our shop is a plastic dial caliper that shows dimensions in 64ths and decimal inches on the dial, as well as millimeters on the slide. If you don't have one, we strongly suggest you get one. They're imported to the US from Switzerland by several companies, including General. We couldn't build instruments without them.
The stock needs to be a little taller (already shown in the Bill of Materials), and the pattern redrawn to make the part taller, so the top can be beveled for fitting the tuning pin box top. The sides also need to be beveled to match the angle of the sides.
The stock needed is 125 x 160 x 13 mm. The holes specified are too large: drill 5/16" holes and enlarge them with the appropriate reamer (see above). You should have your tuning pegs ready before embarking on this reaming, so that you can get them all at a consistant height. Once you've reamed the holes, mark the pegs so you know which peg goes in which hole. I have a storage block of scrap lumber with holes in it that correspond to the the peg positions in the peghead, so I can keep them in order while storing and finishing. Previously I had suggested that the reaming should be done later, when fitting the pegs to the assembled instrument, but someone who built the instrument [GS] pointed out that there isn't enough room for the reamer: it runs into the upright panel.
Cello tuning pegs are fairly expensive, and so is a cello peg shaper, which you will need if you turn them on a wood lathe, and may need anyway for the premade ones. You can make the correct taper (1:25 for cello pegs, 1:30 for violin pegs) on a metal lathe. Make sure the peg and reamer tapers match. You'll need these pegs before you start assembling the peghead, because you need to ream the peghead for them.
Not mentioned by the authors is the tourne-a-gauche (French for " turn to the left"), a tuning wrench traditionally used to hold the head of the peg while turning it. This makes the fine adjustment of the strings much easier, and most hurdy-gurdy players use one.
If you make your own pegs, the shape of the head is variable: they may be rounded (see p. 110), fan-shaped (p. 109), or cylindrical (p. 106, 107). The cylindrical ones are more difficult for some people to use, and they can't be used with a tourne-a-gauche. A sample tuning peg and matching tourne-a-gauche are shown in the Supplemental Plans.
The 1mm hole specified will be too small for some of the strings. Drill appropriate holes later when fitting the strings.
The strips should be 100 x 2 x 3 mm.
Stock needs to be 540 x 160 x 3 mm, 2 pieces. The method of sawing they describe is called bookmatching. It's not essential, but it does make the back look nicer. The center strip grain direction is correct, but the strip needs to be made from several smaller pieces, a little thicker for drilling the soundpost holes (q.v.). The back should be marked and then have the strips glued on so that they don't interfere with gluing the back onto the body.
When cutting out the back, allow a little more than 3 mm extra on the sides, perhaps 1/4" . Some of this extra will get taken up by bending the back into place. Bending with an iron as described isn't a technique we've tried. You may be able to bend the back without heating at all. If you do use an iron, use it on the inside.
Cut out the braces as shown, except that the notches shouldn't be cut yet, and the ends should be about 1/2" longer than shown. You'll file or cut the notches when you fit the braces in place on the body. The holes in the undersides should be 1/4" for the soundposts, which the authors call " supporting dowels". The large hole in brace B need to be customized to the shaft and bearing used (q.v.). The hole in brace A should be drilled now, 7/8" diameter, center 11/16" down from the top. The hole in brace B will be drilled later, after assembly.
The shaft, wheel and bearings are the heart of the instrument. To work well they must be made to very close tolerances: a little sloppiness in the bearing or the wheel mounting will result in some horrendous noises and frustrating problems at the very least, or even an unplayable instrument. Take your time to get it all to fit just right.
The shaft system presented here has some differences from the one shown in the book. We and other makers have used this system with good results. If you have different system, we'd certainly like to hear about it.
Any wheel and shaft system for use in a hurdy-gurdy must meet several important criteria:
With all due respect to the authors, the section on the shaft contains several errors and inaccuracies. To make it workable, the shaft needs some modifications, detailed below and in the Supplemental Plans. It's true that an industrial workshop can make the shaft and bearings for you, but you will probably find it to be prohibitively expensive, because you only want one set. Hardware stores don't have the kind of parts you need for the shaft, though there are a few stock hardware parts in the handle.
Fortunately, there are some alternatives. If you have metalworking experience and a metalworking lathe, the parts shown are relatively easy to make. If you don't have the tools or experience, we suggest making a deal with a local metalworking home shop machinist, perhaps offering to cover the cost of tools, materials, and a little for their time. The hurdy-gurdy is such a strange instrument that sometimes people are willing to help you simply because of its novelty. Home shop machinists can be found by way of the Internet (in rec.crafts.metalworking), model railroad and engine exhibitions, model shops, custom auto and motorcycle shops, or in Home Shop Machinist, a bimonthly magazine.
The last alternative is that we can machine these parts for you. The drawback to this is that in the procedure described here some of the final fitting steps require a metal lathe. It may be possible to do these cuts on a wood lathe, depending on your tooling. If this is your situation, call us and we'll give it a try. In our experience, trying to make the entire shaft system on a wood lathe will not give you enough accuracy for a good-sounding instrument. I'm developing procdures that eliminate the need for a metal lathe for these final fitting sets.
A blind bearing made of Delrin is substituted for the ball bearing shown mounted in brace B. This is the head bearing. Delrin is a self-lubricating acetal polymer similar to nylon, but with more desirable properties. Nylon is not recommended. A ball bearing is also not recommended, as it can create noise which is amplified by the soundbox.
The " screw assembly" is replaced by another Delrin bearing, held in place with a #2 or #4 wood screw. This is the tail bearing.
For mounting the wheel on the shaft, either a modified flange or a Delrin wheel insert may be used. The flange and the wheel insert are shown in the Supplemental Plans. If the flange is used, it is made longer than shown by the authors, so it extends farther toward the head. In both, the headward portion in tapped to match the threads of the shaft, while the tailward portion is reamed to fit closely on the shaft to keep the wheel stable. The reamed section is needed because it's very difficult to make the threads tight enough that there is no wobble in the wheel.
The word "handle" is used to describe both the handle and the crank. The crank is the S-shaped piece of metal at a right angle to the shaft. The French call this the manivelle. The handle is the turned knob you hold when playing, which the French call the poignee.
The handle can be made as shown by forging it from steel, or you can use a piece of straight brass bar stock as shown in the Supplemental Plans. Holes are tapped at each end, one for the shaft, the other for the handle shaft. Again, we suggest a slightly different handle system. It's possible to make a blind hole handle with a Delrin bearing like the one shown in the book, but it takes more tools and time.
To work well (especially to get the dog to work) the handle needs to follow a particular set of dimensions, such as those shown in the Muskett method book. The Supplemental Plans show a sample handle outline and other dimensions. The profile can be varied to suit your hand, but the internal dimensions are critical. You may find a 1/4" expanding mandrel to be useful (such as MSC Industrial's # 09604166). This mandrel requires an Allen wrench to tighten it. The completed handle is mounted on the handle shaft as shown in the Supplemental Plans.
When making the shaft, leave both ends a little long (1/4-1/2") so you can trim them down to the correct length when fitting. This trimming takes some time, but it's easier than remaking the shaft if you make it too short. In the alternate procedure, complete the shaft to the final dimensions shown in the Supplemental Plans.
The wheel can be made from a variety of materials: solid wood, ply or laminate, laminate with a solid or bent banding, or even Plexiglas. Our best results have been with a bent holly band on a Baltic Birch core. Described here is a laminate core with solid wood facings. It takes more work to obtain and maintain a smooth surface on the rim, but it's easier to make than a banded wheel.
The material suggested by the authors, delignite, is apparently not available in the US or Canada. (If you find a source, please let us know!) In its place we suggest Baltic Birch, a similar product with thicker layers. Don't use Apple Ply, which some vendors claim is just like Baltic Birch: the face veneer is thinner, and it's not void-free.
The piece to be faced with hardwood should be oversize. After gluing on the facing, mark and centerpunch the center of the wheel before cutting, and cut the circle blank a little oversize. You need a metal lathe with at least a 7.25" swing to make the wheel. Have the flange or wheel insert already made. Center the circle blank on a faceplate and attach with double-stick tape.
Center drill and bore a 1/2" hole, preferably with a Forstner bit. Cut a 1" diameter counterbore 3/16" deep. Chamfer the corner between the hole and the counterbore. Check the fit of the flange - it should fit snugly without being forced. Mark, centerpunch and drill one of the holes for the wood screws, being careful not to drill too deep. Holding the flange in place with the screw, mark and drill the others. Remove the flange, clean the hole and the counterbore, replace the flange, and put in the wood screws.
Bore a hole in the wheel blank with a 5/8" Forstner bit followed by using a boring bar to the ID of the hole with the OD of the insert. This dimension should be 0.750". Use 2-ton epoxy to glue the insert into the wheel blank with the flat side facing out, using a piece of 1/2" rod in the tailstock chuck as a ram to press the blank in. It shouldn't slide in so easily that you don't need the ram, but it shouldn't bind either. Let the epoxy set and harden overnight. Center drill with a #1 or #2 center drill. Drill though with an F drill. Drill 5/8" deep with an N drill, and ream this section with a 0.3135" chucking reamer held in the tailstock. Deburr the hole. Grind a 5/16-18 H1 spiral point tap to remove the tips of the flutes to a diameter of 0.310. This modified tool lets you tap the insert without damaging the reamed section. Tap the unreamed section with this tap, holding the tap in the tailstock. Remove the wheel from the faceplate and chase the threads in the tapped section from the other side with an unmodified 5/16-18 H1 bottoming tap, advancing the tap no more than 1/2".
The wheel should now fit snugly on the shaft without wobble. Mount the wheel and shaft on the lathe with the spindle nose supported by a live center. Check the shaft for runout with a dial indicator: any inaccuracy at this point will result in unevenness of the wheel surface and a resulting degradation of sound. Trim the wheel faces to shape and trim the outer edge. I've calculated the final diameter of 7.07" , with an angle of 4 degrees as shown in the Supplemental Plans. Don't apply the finish yet.
You should leave the wheel a little larger initially to allow for trimming it later. The diameter of the wheel is important, but is less critical than getting the angle correct so that the chanter strings lie flat on it. This angle adjustment will be done later, with the soundboard and keybox glued on. Don't use the method shown on p. 113: the wrong angle will result because the ruler needs to be lower at the head end. (I'd like to know what your final wheel angle is, to see if my calculations were right.)
The authors use the assembled wheel and shaft to position the braces. We suggest that you glue the braces in place as described below, and then drill the holes for the bearings, as this ensures that the bearings are in line with each other and won't bind the shaft. They also say that the position of the wheel defines the vibrating string length, which is incorrect: the vibrating length is defined by the distance from the nut (at the head) to the bridge. The position of the wheel in relation to the bridge can vary a little without any problem. The position of the bridge in relation to the keybox is critical.
As mentioned above, the authors' method of setting the wheel edge angle should not be used. Do NOT protect a rosined or unrosined wheel with masking tape. Instead, wrap the wheel in several layers of clean, heavy cloth to store it.
The braces can now be positioned, fitted, and glued to the body. Mark a centerline on the top of the tail block. Glue brace D to the head block with the top of the brace just slightly (perhaps 1/32") below the sides, and mark it with a centerline as well. Mark braces A and B with centerlines. Position the braces by measuring from the outside of the tail block to the near side of the brace: Brace A at 4-3/4", Brace B at 8-3/8", Brace C at 14-1/4". Center and square the braces, mark their positions on the linings, then mark each side of the brace, connect the marks and cut them to fit as shown on p.112. Cut the linings to match the ends of the braces, also as shown on p.112. The top of the brace should be deep enough to be even with the inside edge of the lining.
Drill the back center strip 1/8" deep, 1/4" diameter with a brad-point bit directly under each brace. Fit the soundposts to length, then glue in braces and soundposts together.
Make a plywood template with a 19-1/2" radius for checking the tops of the braces and the tail block. File, plane or sand the braces, the upper edge of the sides, the linings and the upper edge of the tail block to this radius so that the soundboard will bend smoothly. Use the straight edge to ensure that the braces are even with each other and the end block, with no hills or valleys. Because the peghead is in the way, this is a difficult step and takes some time. One way to do this is with a long very straight sturdy piece of wood with sandpaper on one side. Sanding is always done with the stick parallel to the centerline. Avoid moving it in a fan shape, and don't let the outer edges get rounded over. (We've never done it this way: we use a sanding jig that sands the entire top to the desired radius, but our jig wouldn't work here because of the peghead.)
Now the bearings and shaft can be fitted. Mark a centerline on each brace, and make a jig as shown in the Supplemental Plans, marked with a centerline on top and bottom. Place it on the instrument with double-stick tape, aligning it with the centerlines on brace C and on the tail block. Drill carefully with a brace and bit, using a sharp 5/8" auger bit. Do not use a spade bit, a twist bit, or a bradpoint. After drilling the hole through the tail block, remove the jig. Mark and punch a center on brace B, 11/16" down on the centerline, and drill through the brace at that point.
Fit the head bearing into this hole. The spindle nose of the shaft needs to be polished to fit smoothly in the bearing, but not loose. The shaft need not turn freely yet, but the shaft must fit in the bearings and the bearings must fit in their holes. Glue in the head bearing with 2-ton epoxy, using the shaft and untrimmed tail bearing to keep it aligned while the epoxy hardens overnight.
Trim the spindle nose to length so that the distance from the wheel to the outside edge of the tail block is 6-1/8" . This should be done in several steps to avoid overtrimming. Polish and deburr the trimmed end each time, to prevent the burr from damaging the head bearing. When the wheel position is correct, trim the tail bearing flush with the tail block surface. Fit the retaining screw (a #4 x 1/2" brass Philips head wood screw) at the junction of the bearing and tail block, using triangular and round files. Continue filing until the head of the screw is flush with the surface. The shaft should not bind or tighten when the screw is in place. If it does, file some more, but don't file so much that the screw no longer holds the bearing firmly. When fitting is complete, remove the shaft, wheel and tail bearing and store them until the body is complete.
Here is the alternate procedure for fitting the shaft and bearings, with the shaft provided fully machined. Glue in the head bearing as above. Check the fit of the shaft and bearing. If the distance from the tail side of the wheel to the outside edge of the tail block is less than 6", the bearing will need to be drilled a little deeper. 6-1/8" is the ideal distance, but anywhere between 6" and 6-1/4" is acceptable. To drill the bearing, use a 9" or 12" long 1/4" diameter airplane drill with flute length of 3" or less. Protect the tail bearing hole and align the drill with a Delrin guide bushing with 5/8" OD and 1/4" ID. Chuck the bit in a handheld power drill set for low speed and put the guide bushing in the tail bearing hole. Delrin is easy to drill. Insert the drill bit through the bushing into the head bearing and advance gently. Remove the drill and bushing, and check the shaft measurement. Repeat this procedure until the measurement is between 6" and 6-1/4".
To trim the tail bearing in the alternate method, determine how far out the bearing extends beyond the body. If a wood lathe with a 3-jaw or 4-jaw chuck is available, you can trim the bearing flush with the body. Use a skew chisel to lightly trim the face of the bearing, and deburr the hole with the tip. Remove and check the length, and repeat until the bearing is flush with the body. If no lathe chuck is available, a drill press or a drill chuck on a Shopsmith may be used. The bearing is held with a threaded holding fixture, and the edge is trimmed to a 45 degree angle with a cabinet scraper, a skew chisel, or a file. Delrin doesn't look very good when filed or sanded, so this is the less preferable choice.
The holes for the keys should be 9/32 x 3/16. Lay out and mark the keys as shown, marking each side on the outside. Lay out and mark the nut position on the top edge of each piece, 20 mm from the center of the first top key. Don't drill as described: centerpunch and then use a 1/8" bit (brad point preferred) to drill each piece separately from the outside. You can then use a fretsaw or a coping saw to remove most of the remaining waste, but be careful not to overcut. File to almost complete the hole.
The keys must slide easily without wobbling around. Leave the holes a little undersize so you can fit the keys when the instrument is assembled. For keybox cover hinges we suggest making your own from copper or phosphor bronze wire, as shown in the Supplemental Plans. Wait to drill the holes in the keybox sides until later when you fit the cover.
The keybox shelf (which they call the front panel) needs to have the little divider set down in a dado or groove. The keybox end block (which they call the back panel) needs to be modified to accommodate the chanter rests as shown in the Supplemental Plans. When fitted to the body, the screw should extend no more than 3/8". Substitute a shorter screw if needed, to avoid running into the head bearing.
The key stock is 9/32 x 3/16. A router table is probably a safer way to cut the 3/16" channels in the key front strips. The authors show a difference between the key stock (5 mm) and the channel (4mm) but these dimensions should be the same (3/16" ).
The holes in the keys must be the right size for the tangents and will be drilled later, discussed below. Making the tangents is also discussed later.
The friction peg in the tailpiece does not tune the trompette, as the authors say. It is used to adjust the sensitivity of the dog. Several changes are needed in the tailpiece, as shown in the Supplemental Plans. The body needs to be thicker, and the hole for the trompette adjustment peg needs to be in a different place, a different size, at a different angle. Mark and drill for the peg, the strings, and the hole for the violin tailpiece adjuster. Don't drill the holes in the foot yet.
When the soundboard is glued on and the keybox attached, fit the foot to the curve of the body. Make a tapered peg as shown the the Supplemental Plans, or buy a violin peg. Ream the hole with a violin peg reamer so that the bottom of the peg just rests on the soundboard. Mask the soundboard for finishing.
Chanter bridge stock should be 80 x 66 x 12-13 mm. Lay out as shown, but leave extra at the top, and omit the heart-shaped cutout near the top. Bevel to 1/16" at the top, 1/2" at the bottom, keeping one side square as shown on p. 118. Don't file the notches in the top yet.
Bourdon bridge stock should be 40 x 30 x 10 mm. Cut shape as shown and mark for the notches, but don't cut them yet. Choose a material for the retaining cord for the wheel cover, and drill the hole for it as indicated. Thick gut (2.0-2.5mm) is the traditional material, but is not widely available.
Dog bridge stock should be 40 x 30 x 10 mm or thicker. The bridge may be tapered or shaped on the side opposite the slot for the dog, but must be flat on the side with the slot. Many hurdy-gurdy players use the French name chien for the dog, which is made of a fine-grained hardwood, such as boxwood or Indonesian boxwood. Some people use maple or English sycamore. The wood you choose should be strong, hard, well seasoned, and have minimal difference between the earlywood and the latewood of the annual rings. You should buy enough to make several dogs. The dog shown by the authors is large and unrefined: it should be smaller, with a narrower head and front foot. Typical dog designs are shown by Destrem and Muskett. The dog's motion when activated is up and down, not in and out as described. Wait until the instrument is strung to make and fit the dog.
This is the trompette rest. The profile shown is too tall and too wide to easily engage the trompette, and might cause the dog to fall out. A smaller, shorter design with a notch at the height of the string is suggested, like that shown in the Supplemental Plans. Make this later, after the strings are fitted.
The wheel cover blocks (" support strips" ) should be wider to increase gluing area and to allow for fitting, and shorter to match the end of the wheel cover: 15 x 15 x 60 mm. It's easier to bend the wheel cover stock first and cut it to shape afterward.
Don't drill the hole yet. You'll need a form with an 8" diameter, 3" wide, or you can bend bend it by hand on a bending iron. The stock should be 330 x 80 x 2 mm. We haven't tried the boiling method described on solid wood this thick, but it ought to work. Our results with ply haven't been very good with this technique. Once the cover is bent, maintain the curvature by holding it on a board with two blocks positioned to keep it somewhat compressed.
You can use standard guitar strap buttons. Before fitting the soundboard, drill holes for the strap button screws in the head block (in the center, 1" from bottom) and the tail block (3-1/2" from center on the trompette side, 1-1/2" from bottom). You'll install them later.
Make the soundboard as described. Cut the hole for the wheel first, with an opening for the extended flange or wheel insert so the wheel can be removed. Fit the soundboard over the wheel and note whether the head end fits neatly against the peghead. If not, trim it a little until it does. Bend gently into place and mark around the edge. Be careful when bending into place the first time - the opening for the wheel may need to be enlarged at the sides to allow for the curvature. Cut out the blank with 1/4" overhang all around except where it touches the peghead. Cut out the soundholes, positioning them to avoid the braces and the tail block. Put your maker's mark on the inside of the back under one soundhole.
Put in the shaft and wheel. Position the soundboard relative to the wheel and drill a 1/8" hole at the tail end, 1/2" from the centerline, 1/2" deep, 3/4" in from the edge of the oversize soundboard (you have 1/4" overhang, so that's 1/2" in from the edge of the tail block). Insert a piece of 1/8" dowel. Mark the position of brace C and reposition the soundboard if needed. Drill on the centerline in the middle of brace C, 1/2" deep. Insert another pin and check your position again. Cut the positioning pins to 1/16" above the soundboard, remove the soundboard, and glue in the pegs. Remove the wheel and shaft. Glue the soundboard as described, fitting the soundboard over the pins. Trim the pins level with the soundboard, and trim the edges even with the sides.
Before finish is applied, fit and apply masks for the tailpiece, drone bridges, chanter bridge, keybox, and wheel cover blocks. These parts will need to be fitted to the curve of the soundboard. Fit the keybox first, placing it on the centerline and drilling for the screws. Use the keybox as a reference point to center and position the tailpiece. Make the triangular chanter nuts as shown on p.118. The authors call them bridges. The nuts must be carefully fitted so they are snug, and positioned 20 mm from the center of the first top key. The notches should be exactly 1-1/8" apart, each being 9/16" from the centerline of the keybox. Keep the notches shallow for the moment.
Put the wheel and shaft in to position the chanter bridge. Use a piece of thread to examine the wheel angle by stretching it from the nut over the wheel. If it lies flat on the wheel, count yourself lucky. If not, you can adjust it with a scraper as described by Destrem or by putting it on the lathe again. Keep adjusting until it's right. Don't assume that the angle can be adjusted later: the wheel angle is defined by the chanters, and it then defines the positions of the drone bridges.
The chanter bridge should also be glued on, though the authors recommend otherwise. Place it with the headward side 343 mm from the nut position. This 343 mm is the sounding length or scale length. Fit the bridge feet to the soundboard while maintaining the right angle as shown on p.118. Trim the top of the bridge to 2-3 mm above the wheel level. Mask the locations of the feet, but don't glue the bridge on yet.
Fit and position the drone bridges. For each string, use a thread or a plastic ruler to establish the location of the holes in the head block. The trompette and petit bourdon should be about 8 mm above the soundboard, the gros bourdon about 20mm, and the drones should all be parallel to the soundboard. The trompette string length is 400 mm. Make a sample dog for positioning and use the thread to position the dog and its bridge so that there is a straight line across the surface of the wheel. Mask the position of the bridge. The bourdon string lengths are 415 mm. Repeat this procedure with the bourdon bridge, positioning it so that the strings will only contact the wheel when the notches are filed. This is a little tricky, as the outline of the bridge may need to be altered to allow equally deep notches for the strings.
Drill the holes for the strings: 1/8" for the bourdons, 1/16" for the trompette, 1/4" for the chanters. You can hand drill with a bit held in a pin vise, which doesn't really take very long and is very controllable. I had previously suggested that a Yankee push drill may be able to drill these holes, but I know think that it's a bit too risky. The holes should be angled slightly down and toward the centerline. The holes for the chanters should be centered 3/16" above the keybox shelf, 1-1/8" on center, each 9/16" from the centerline.
The wheel cover and its blocks also need to be fitted. Fit the blocks to match the angle of the cover where it meets the soundboard. Set the blocks slightly toward the centerline to compress the cover a little bit (perhaps 2 mm) to hold it in place. Mask for the blocks. Mask the bottoms of the parts also. With all the masks in place, finish the body and the parts separately.
Drill a hole through the soundboard into the head bearing for oiling the bearing. The hole should be just tailward of the keybox end block. Lay out and centerpunch the position of the hole. Use a 1/8" bradpoint to start the hole, then continue with a 1/8" twist drill. When the bit hits the Delrin bearing, drill gently to avoid damaging the bearing when the bit breaks through. You may want to make a small metal sleeve to protect the soundboard from oil seepage. We use a stainless steel sleeve.
Glue the parts on in order: keybox, tailpiece, dog bridge, bourdon bridge, wheel cover blocks, chanter bridge. When gluing on the tailpiece, use the peg to support it. Make sure it's on center and square, using the keybox as a reference point for a centerline. When the glue is completely dry, drill 3/16" holes in the tailpiece and tail block as shown in the Supplemental Plans, not drilling any closer to the center so you'll avoid hitting the tail bearing. Cut pins from 3/16" dowel and glue them in, filling the hole with wood putty or tiny decorative turned buttons. Trim the end of the tirant peg about a millimeter so it just clears the soundboard. Make a lengthwise cut about 1/4" long with a razor saw for gripping the tirant.
Now it is time to fit and drill the keys. File the holes for the keys to get a smooth sliding fit with very little wobble or play, keeping the holes square in all directions. This is a long process. Remove the keys and glue a strip of felt or suede along the inside of the keybox to cushion the tangents when the key is released. Position a piece of extra key stock so that it extends about 1/16" from the back of the keybox. Hold a tangent in place against the cushion and mark the key for drilling the hole for the tangent. Mark the hole for the second tangent exactly 1-1/8" away. Put the test key and tangent in to check the hole position: the key should still extend about 1/16". Mark all the keys with identical marks, using the test key as your standard. Drill the keys for the tangents, drilling in the center of the key and keeping the drill square. Use a drill press with a bradpoint bit if you have one. Be VERY careful to drill the holes in each key shaft the same distance from the end, the right distance apart, and in the center of the shaft.
The making and fitting of tangents is an art of its own. Destrem and Heidemans have a good description of it. Don't use the tiny shafts shown on p. 115. We've never tried the PVC tangents. We suggest a 1/8" thick hard rock maple tangent stock with 1/8" diameter tangent shafts. This should make the shafts tight enough to hold well, but loose enough to turn by hand. Trim the tangent shaft down until it's almost round and still a little oversize, then compress the shaft in a series of successively smaller holes in a block of hard rock maple or Delrin. (We suggest #28, #29, #30, and 1/8" holes.)
The chanter bridge is attached to the tailpiece with a violin tailpiece adjuster instead of the S-shaped wire. The adjuster is a piece of nylon with a smooth center and a tiny nut threaded onto each end. Remove and save the nuts. Cut the adjuster about 1/4" longer than shown in the Supplemental Plans. Heat the smooth end gently with a blowtorch or lighter. The nylon will soften. (If it catches fire, blow it out!) Flatten it with pliers while it's still warm, then let it cool. Check the fit in the hole in the tailpiece. Melt and reshape as needed to get it to hold securely.
Mark the chanter bridge in the center at the height of the adjuster. Drill this hole with a bit that's as close as possible to the diameter of the adjuster threads. Check the fit and position. If it's good, glue on the chanter bridge. Wait until it's dry to thread the adjuster through and put on the nut.
When fitting the keybox top, leave a small gap at the peghead end so that it clears the peghead. Insert and bend over the hinges as shown in the Supplemental Plans.
We recommend the following string dimensions:
You already have the holes drilled in the peghead. The U-shaped string holders described have several drawbacks: they bend the string excessively and the strings dig in to the edge of the soundboard. One solution is to drill holes at an angle though the tail block and soundboard, starting 3/8" down and drilling up at an angle of about 25 degrees, aiming to emerge from the soundboard about 3/4" from the edge. The holes are placed to provide 0" to 5/8" deflection toward the centerline, depending on the string. The trompette has no deflection from the line of the string, i.e. the hole in the top is in line with where the string ends up when it's stretched or extended from the peghead over the wheel. The petit bourdon hole is 3/8" toward the center from its line, and the gros bourdon has 5/8" deflection. Drill these holes that match the string diameter as closely as possible, allowing for the wrapping on the wound strings.
Ream the holes in the peghead to fit the pegs, keeping a peg assigned to each hole. Drill the pegs for their strings with an appropriate size drill bit, about 1/2" from the bottom of the peg. Put the strings on the pegs so that they are tightened when turned counterclockwise (i.e. to the left). Make the tourne-a-gauche as shown in the Supplemental Plans, with the end shaped to fit the heads of the pegs you have chosen, The tourne-a-gauche is often drilled for a cord which loops over the pegs, for easy availability.
Use the keybox as a reference point to mark a centerline on the chanter bridge. Mark 9/16" out on each side and file shallow notches with a triangular file. Make similar shallow notches on the bourdon bridge 7 mm and 20 mm from the soundboard. String the instrument with the chanters first, deepening the notches until the strings just touch the wheel. At this point you may need to scrape the wheel, as described in the Destrem book. When the wheel surface preparation is completed, you can apply finish to the wheel if desired, but avoid getting finish on the rim. Use a lacquer or varnish for the wheel, not an oil finish. When finishing is complete you will probably need to rescrape the rim to remove the finish that inevitably gets on it.
String the trompette string next. The light cord or heavy thread between the trompette and the peg in the tailpiece is the tirant. We suggest using silk for the tirant because of its strength. Both pictures on p. 118 show excessive tirant tension. Fit the dog as described in Destrem (the better source) or Muskett. Make the trompette rest peg, drill and glue it in.
String with the bourdon strings last, again deepening the notches until the string just touches the wheel. Don't turn the wheel with the wire-wound strings touching it until the cotton is applied. File the shallow "rest" positions above the "engaged" positions.
Install the strap buttons. A standard guitar strap is good for playing the hurdy-gurdy while seated. Rosin the wheel and put cotton on the strings. These are described in Destrem, Muskett, and the Olympic Instruments video.
We suggest the following tuning:
Congratulations on completing your hurdy-gurdy! There are method books available, most in French and one in English (Muskett).
Updated page format (8/15/05)
Added link to PDF file of drawings (10/31/04)
Updated page format and table formats (9/28/00)
Added note about scale length and bridge position (1/22/98)
File of drawings: updated Corel 5.0 to Corel 7.0 (1/22/98)
Updated suggested string sizes (1/22/98)
Updated re reaming peghead before assembly (1/22/98) (thanks to Henry Boucher)
Converted format for new domain (2/27/97)
Notice about book being about of print (7/19/96)
Remove references to mesquite in materials list, add cornelwood (7/19/96)
Minor improvements and clarifications (3/8/96)
Added discussion of oil hole and sleeve (3/8/96)
Move chanter bridge fitting procedure (3/8/96)
Updated wheel cover to include hand bending (3/8/96)
Added alternate shaft fitting procedure (3/7/96)
Change in wheel finishing instructions (3/7/96)
Updated back panel dimension (3/6/96)
Shop Safety section (3/6/96)
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