Making a xylophone. You will need: Marking and measuring tools (tape measure, ruler, chalk, pencil)

Transcription

1 Making a xylophone You will need: Marking and measuring tools (tape measure, ruler, chalk, pencil) Logs of straight grained, knot free timber, preferably at least 2 inches in diameter. The instrument made using these instructions requires 3 logs, of 10, 12 and 14 inches in length. a saw to cut the logs to length a stable support upon which to rest the logs while sawing an axe or froe or billhook to split the logs a mallet with which to strike the splitting tool

2 a chopping block to rest the logs upon while splitting and chopping a billhook or side axe to roughly shape the keys a shaving horse, workmate or other device to clamp the wood while removing bark and shaping the bars to tune them a drawknife or billhook with which to shape the bars a drill to make holes by which the bars can be held rope or string to hold the bars web: web: timcumine@soundwoodlinks.org tel: tel:

3 1. Cut a set of logs to length Saw 3 logs of 10, 12 and 14 inches in length. Wear a glove on the hand that isn t holding the saw Split each log down the middle Rest the log upon the chopping block with the thinner end upwards. Rest the sharp edge of the splitting tool flat across the sawn face of the wood such that it passes through the centre of the wood. If the pith is not in the centre, turn the wood so that an equal amount of wood is either side of the splitting tool. Make sure that if you hit the splitting tool and the mallet bounces back, other parts of your body are safe from any rebounding impact. If using a froe, this means gripping the handle with fingers yet pointing the thumb upwards so that it is safer see picture below. Strike the splitting tool firmly with the mallet. If the wood does not split into two at the first attempt and the edge of the splitting tool has not yet firmly lodged into the wood, reposition the edge and strike it again. If the splitting tool is firmly lodged in the wood you might be able to lift the tool and the wood together and strike the wood on the chopping block. This can be as effective and controlled a way of completing the split as hitting the tool again. 3. Reduce the length of one of each pair of blanks by 1½ inches Saw an inch and a half off one of each of the pairs so that you have a range of 6 half round timbers of 8 ½, 10, 10 ½, 12, 12 ½ and 14 inches 1 Try to establish which way up the logs grew on the tree. This is important when splitting timber evenly as it is best to start a split at what would have been the upper end of the log. The thicker ends are almost always nearer the ground. If the log is of even thickness, branches generally grow upwards. If there are no branches, any which have been removed or which have bark grown over them might have a suggestion of a roof shape to the bark on the upper side of what remains of any side branching. If the log is of even thickness and there are no visible knots it isn t so important which way up you use the timber!

4 4. Mark out the central 2 inch width of each blank Measure the width of one end and mark the central point Mark one inch either side of the central point Repeat this process at the other end Join up the marks along the split face of each blank to show the central 2 inches 5. Reduce the width of each blank by chopping it back to just over 2 inches Wear a glove on the hand holding the wood. Hold the chopping tool (axe or billhook) in a bare hand. Place the end of the wood on the chopping block and tilt its top over slightly, away from the chopping tool. The benefit of this is that the blow from the chopping tool is directed as straight as possible downwards towards the chopping block. Making sure that you do not raise the chopping tool higher than the gloved hand which holds the wood, make a small chip in the slanted wood near the lowest point of the wood. Your chopping stroke should go straight down towards the chopping block. Make repeated chips in the side of the timber to be removed, each time about half an inch higher than the previous cut. Do not make these chips higher than half way up the length of the timber. web: web: timcumine@soundwoodlinks.org tel: tel:

5 Straighten the wood so that it is held vertically on the chopping block. Bring the chopping tool straight down to remove the chips which were made while it was slanted. Turn the wood upside down and repeat the process on the other end of the wood. Turn the wood round to repeat this process on the other side of the wood. 6. Flatten the chopped sides to reduce the width to 2 inches If a shaving horse and draw knife are available they may be used to smooth the roughly chopped blanks to size Alternatively, the same chopping process as in 4 above may also be used, only more delicately, to produce a flat edge on the xylophone bars. 7. Remove the pith from the split face of the blanks The tools and techniques described at 6. above may be used to reduce the thickness of each blank so as to remove any softer pithy sections of the wood. This process will also help flatten this split face. 8. Flatten the rounded halves to reduce the thickness to 1 inch Mark one inch thickness at each end of the bar

6 Either draw knife or chop the rounded face of each bar to reduce the thickness to 1 inch. Using draw knife, chopping tool or penknife, remove any remaining bark. 9. Listen to the note of each bar Hang the bar between thumb and forefinger at a point around two ninths of the length from the end and strike it in the middle with a stick. Try to remember the note. Find it on a musical instrument if you have one to hand. 10. Remove an arched portion of wood from the centre of each bar Mark an arch which spans between a third and a half of the side of each bar, whose height is roughly a half the thickness of the bar This process will not only make the resulting note clearer, it will also lower the pitch of the note produced. Using either drawknife or chopping tool remove an arched portion from the centre of one face of each length which spans roughly between a half and a third of the length. The top of the arch can reduce the thickness by up to a half of the full thickness. You will need to work towards and no further than the centre of the arch, then turn the wood round and work towards the centre from the opposite end.

7 11. Listen to the note of each bar again Hang the bar between thumb and forefinger at a point around two ninths of the length from the end and strike it in the middle with a stick. Try to notice how much lower the pitch of the note has dropped by sculpting the bar in this way. Find it on a musical instrument if you have one to hand. 12. Drill holes through the two nodes of each bar The nodes are the points which are about two ninths from each end of the xylophone bars. As the bar vibrates to produce sound these points remain still. The note produced by the bar will be clearest if any supports are at these node points. To find the nodes, hang the bar between thumb and forefinger and strike the bar in the middle with a stick. It may help to hold the bar low enough to position your ear above the upper end of the bar. Mark the points where the note sounded clearest and drill through the width of the bar. A drill bit which is 1mm larger than the thickness of the rope or string to be used is sufficient. The rope pictured is 5mm and a 6mm drill bit is sufficient to enable this to pass through the wood. 13. Tune the keys to the notes you want The pitch (high or low note) of a xylophone key can be lowered by shaving or chopping wood away from the middle of the key (best taken from the underside). The pitch can be raised by taking wood away from the ends. Note in the picture below how the ends of the second key from the top were shaped to raise the pitch of the note. The bars of the xylophone pictured here produced the notes C, D, E, G, A and C, the 1 st, 2 nd, 3 rd, 5 th, 6 th and 8 th notes on a scale of C major. An electronic tuner, downloaded as a smart phone app was used to check the pitch of the notes. 14. String the keys on the rope Cut a length of rope, long enough to allow: o one knot per key on each length which will take up roughly ½ inch per knot i.e. 6 keys will require 3 inches, o 1 inch between each key i.e. for 6 keys allow 5 inches, o the width of all the keys i.e. 6 x 2 inches = 12 inches

8 o o the ends to be knotted above the instrument to create a loop by which to hand the instrument; an extra 12 inches on each length above the instrument should be enough, and a loop below the instrument to reach the ground to be pegged or weighted so that the lower portion of the instrument doesn t swing wildly while being played. The length of this lower loop will depend on the height of the players. Notes The word xylophone has Greek roots, where the xylo part means wood and the phone part means sound or voice. Any long thin strip of wood will vibrate to produce a note when struck in the middle of its length. There are two points along the length of a xylophone key which always remain still. These points are called nodes and they are found roughly two ninths of the length of the key from each end. The clearest note is produced when a xylophone key is secured (held, rested upon, suspended, etc.) at its nodes. It is helpful to aim to make all the keys the same thickness and width, for ease of tuning and playing. It is not essential though. A range of notes can be produced from keys of differing length and thickness or indeed from several keys of the same length. It helps to produce a clear note to scoop out some wood from underneath the centre of the key. In general, the longer and thinner the key, the lower the note will be. The shorter and thicker the key, the higher the note. Hardwoods and softwoods all produce musical notes in this way. Dry, seasoned wood will ring clearer than fresh, green wood. The note in any xylophone key will be clearer if the wood is taken from knot free, straight grained timber. Some timbers ring out better than others due to their internal structure. Some good ones to try are sweet chestnut, poplar, hazel, cherry and sycamore.