a generic blog
Thursday, May 12, 2005
 

(Click on thumbnails for full size image ; Click on the "mp3" link to listen)


With the exception of the wire strings, this instrument is entirely constructed out of LEGO parts--the keyboard, jacks, jack rack, jack rail, plectra, soundboard, bridge, hitch pins, tuning pins, wrestplank, nut, case, legs, lid, lid stick, and music stand are all built out of interlocking ABS (Acrylonitrile-Butadiene-Styrene) plastic bricks and related pieces.

And is playable.

Specifications include a 1 x 8' disposition (single choir (one string per note), middle C corresponds to middle C on other instruments), single manual (one keyboard), 61 note range (5 octaves, C-c'''', A415), 6 x 3 ft. dimension, approximate 150 lbs. weight, and an estimated 100,000 LEGO piece count. The strings (brass gauges .012-.018 and steel gauges .008-.012) exert approximately 325 lbs. of tension.




Audio example mp3




It's taken two years of theorizing, designing, collecting parts, building, testing, and rebuilding. Originally, upon thinking about the potentials of making a LEGO musical instrument, I had hoped to reproduce a piano, but ditched the idea due to the enormous tension involved (40,000 lbs.)--there's a reason why pianos have steel frames. Its ancestor, the harpsichord, seemed more practically possible--the key/jack workings are simple levers, the strings are plucked, it's smaller, and it maintains less tension. Coincidentally, I was in my Bach phase anyways.

The important considerations during design were strength, efficiency, and durability. Anticipating the tension of the strings, the instrument had to be built strong, yet be able to incorporate the functions and mechanisms on a lifesize scale. With many moving parts, it also had to withstand the repeated demands of a keyboard instrument. Several prototypes of the various sections were made. After finalizing designs, I started amassing the necessary LEGO parts.




This instrument would not have been as sturdy without the use of larger sized bricks, such as the 2x8 and 1x16. Staggering these and the sheer reach they afford established the structural integrity. Large plates (mostly 6x8 thru 6x16) and wing shaped pieces (6x6 and 6x12) were packed abundantly (three plates thick) to build the interlacingly secure bottom. A three braced frame in the soundchamber and a two brick thick grid under the bottom plates completed the foundation.

Also,
Technic ("mechanical" LEGO) parts were relied upon to create the keyboard pivots, locking supports for the soundboard and wrestplank, bridge and nut mounts, hinges for the lid, underside of the jack rail, and the tuning and hitch pins. Foremost amongst these were the holed 1x16 brick, 2x8 plate, 1x7 liftarm, and long friction pin. However, as tight as the pins held in the holes, they weren't capable of keeping taut, let alone pitch. Taking pipe cleaners dabbed with PVC cement, I melted the holes so that the pins could hold the strings tightly while still being able to turn for tuning.

Acoustically, the instrument would benefit from being as smooth as possible, so instead of having the standard LEGO studs exposed, I covered them up with tiles (smooth topped flat pieces). Besides the functional studs that align the strings on the bridge and nut, no external stud is untiled. Likewise, the entire unseen floor of the soundchamber is decked with hundreds of
1x8 tiles. The end result is as resonant as LEGO will get.

Single studded 1x2 plates were most convenient not only to build between studs (which was necessary for jack alignment), but as the basis for the plectra--after some bansaw and surgical scalpel mutilation.

Some of the more whimsical LEGO elements were integrated as well:
arches (and inverse arches) for the soundhole, roof slopes for the "curvature" of the internal frame and leg decorations, rubber tires to reduce the "clack" of the keys and jacks, and cloth capes (as worn by the likes of the Hermione Granger minifig) for the dampers.

Mosly these were ordered in bulk from
LEGO Shop At Home and Bricklink, with some parts (the majority of the 1x8 tiles) obtained from the Legoland California Model Shop store.


















I started with the keyboard first, making sure it was translateable on a lifesize scale into LEGO. Luckily, there's just enough space between the keys--any less and the friction would've caused them to stick. Elemental to this design is the sideways alignment of the bricks on the natural keys as the accidentals are built with the conventionally upward pointing stud. After designing a preliminary jack (which itself went through a dozen evolutions, especially after being strung), the rack was built. Despite having a single manual, the rack is double rowed, half a stud displaced. This allowed for the key/jack configuration. These designs were repeated 61 times.

The casing was made next. This was standard building. Well, the bentside was done with
turntables to swivel the bricks as they traced the angles of the winged bottom. After going through about a third height of the case, the five legs were attached. These took advantage of skeletally stacked grid patterned 2x8s and the weight of the instrument for firm elevation.

The soundboard and wrestplank were built laterally in relation to the casing--the studs face to the side. This was done in order to preserve the smoothness of the bricks' sides and to counter the tension of the strings--with this design, as the strings pull they hold the soundboard and wrestplank together rather than ripping them apart if built otherwise. Technic parts were used to secure these directional changes of the studs. As the bridge is mounted upon the soundboard, reasonable speaking length (the distance between the bridge and nut) recalculations called for several revisions of that entire section. Then it was locked into place as the case continued its building. The lid was constructed, but removed to enable easier access for stringing.

LEGO as a medium holds rather well, not to mention is heavier than hell on a compoundedly large scale. This weight is what holds the parts together and ultimately handles the tension. During stringing, as I cranked the tuning pins, often I'd hear a disturbing creak off in a corner. I'd check the case, soundboard, and wrestplank for faults as there was the fear that the whole thing would implode. There's a certain self personification projected onto an instrument of one's own building. I spine crackingly empathized with the literal tension. A growing crack was forming behind the tuning pins, to the point that each added string increasingly threw all the others out of tune. I reinforced the wrestplank (doubling its thickness). So far, it's holding.

















The final jack design couldn't be realized until they were activated. Only after seeing (and hearing) how they were plucking the strings could I devise the plectra all within the space of about four studs. At this point I'd figured out I was gonna use the single studded 1x2 plate securely attached (and adjustably so) to a 1x7 liftarm as the most minimally complicated and maximally effective solution. Two problems occurred: the back end of the plate was hitting the neighbouring string and there was a nasty downward pluck. Simply, I shaved off the edges with a bansaw to allow for only one string to get struck and I carved out the bottom of the plucking end with a surgical scalpel to allow for a sweep upon return.

This didn't completely eliminate the downward pluck, but it was better. Dampers also helped the matter by silencing the ringing of the strings when the keys are released. For these, cloth capes were rolled, cut, and glued (Duco cement) onto the bottom of sliced single studded 1x2 plates.

The jack rail serves to contain the jacks from flying out of the rack and acts as a buffer which determines key action. I've set it pretty tight, giving the jacks very little room to move--beyond my preferences, this was purposeful as restricting the leeway presents a more consistent sound. Hubless tires suspended on axels, one per jack, were hung underneath the rail.

Along with the jack rail, the nameboard is removeable just in case any adjustments are needed. Due to the odd angles of the bridge and nut, the strings come in from whacky directions, which means each plectrum has a different orientation. All 61 notes need to be uniquely calibrated.

The lid was tricky in that building it sideways (for smoothness) meant that it crumbled from it's own weight. Supports were made, but still couldn't keep it together. So I glued (PVC cement) the supports. The lid hinges on Technic parts with the case, but the front flaps were made with actual LEGO hinges (
bases and tops).

The lid stick is seemingly flimsy, but like the rest of the instrument, is a sturdy combination of large bricks with studs going at opposite directions, packed with plates, fastened with Technic parts, tiled for smoothness, and serves its little function. Music stand
simile.


















Thanks:
- Robert Portillo, for expertise and wire
- Umberto Belfiore, for recording and helping with the lid
-
Eric Harshbarger, for leg attachment assistance
- Mike Wong, for bumping into it and dude, proving just how stable it is
- UCLA Music Library, for reference material

Reference:
- Kern, Evan J.:
Harpsichord: Design and Construction (New York, 1980)
- Neupert, Hanns:
Harpsichord Manual: A Historical and Technical Discussion (Kassel, 1960)
- Paul, John:
Modern Harpsichord Makers (London, 1981)
- Ripin, Edwin M., ed.:
Early Keyboard Instruments (New York, 1989)
- Schott, Howard:
Playing the Harpsichord (Mineola, 2002)
- Zuckermann, Wolfgang Joachim:
The Modern Harpsichord: Twentieth-Century Instruments and Their Makers (New York, 1969)
 
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a gentle awakener, a ready believer, a private citizen, a romantic dreamer, a tranquil idealist, an aspiring musician, a natural philosopher, a compulsive photographer, a latent poet, a wandering reader, a dreamy romantic, a practicing scientist, a ubiquitous thinker, a (no longer) lone traveler, a pensive writer, ...

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