Month: March 2010

The Big Picture is all in your head

By now you’ve probably gathered I’m not an engineer. None of the XyloVan team is, really.

As a result, this build blog is more a chaotic pile of raw coverage than a fetishistically neat, step-by-step how-to.

This rolling concert instrument (I do dream of a fleet of instrumental art cars – DrumVan, or PianoBoat, anyone?) is taking shape in a raw, organic form in our minds .

I’m not computing engineering challenges ahead of time. I’m figgerin’ ’em out as soon as I get my hands on the materials.

This means I use sketches as a sort of problem-solving tool rather than a full-on architectural spec.

So this one (above) is one of the earliest, showing a three-quarter view and all the gross components we’re planning to build and attach – xylophones, gongs, lights, sun-shelters, speakers, etc.

I’m posting these largely because tonight’s the deadline for Maker Faire entries and we’re hoping to have the van in some kind of playable shape by then.

So on the one hand, you have crudely-detailed sketches like these:

And on the other hand …

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Finding the nodes, drilling the keys


(video lost when we quit Facebook)
Once the keys are cut and rough-tuned, they must be mounted.

Step one is finding the “nodes,” or the dead spots at either end of the key where the metal doesn’t vibrate. This is where I’ll drill holes for mounting.

To do this, you park the key atop two pairs of balled-up socks so it vibrates when struck. Then sprinkle a little salt near either end of the key and whack it repeatedly. The resonating metal bounces the salt away from the most-vibrating part into the nodes, the deadest spot in each key …

I mark each key, then put it on the drillpress and drill a 3/8-inch-diameter hole through each key’s nodes.

Drilling one of the two keyboards (about 30 keys) took the better part of an hour and resulted in several pounds of this fantastic aluminum chaff.

Wonder what I should do with it all …

Tubular bells array – sound check

(video lost when we quit facebook)

Here’s the first set of tubular bells, untuned. Tuning them is a pain in the ass: Unlike the keys, these cannot be made flatter by hollowing out the middle, between the nodes.

Instead, you can only sharp them by carving slices off the ends. Luckily, I wound up creating a sort of Middle-Eastern koto-sounding thang, that kind of works. I hope these don’t dull down too much when I mount them.

Miking and amplifying will be a challenge – I’ll need to figure out a resonator or some sort of sound funnel feeding a mike at one end of the tubes. But they resonate deeply, and they’ll look pretty wikkid bolted to the side of the van.

Enjoy the sustain.

Junkyard crawl 3 – The re-dooring of XyloVan

It’s promisingly non-rainy gray when we set out. The minute we arrive at the junkyard, the sky tears. A good, heavy rain soaks us and everything around us, but it’s a good day to be slogging around with wrenches in our fists and a plan.

This is the day to replace the door I smashed.

We wander around the van section of PickYourPart looking for XyloVan’s ghost twin. Identical paint job, identical van, it would have been a perfect match.

But it is gone. I guess the yard declared it well and truly stripped and sent it off to the crusher. In its place are a few more options, but it takes a good 45 minutes sloshing around through oilslicked pondlets 30 feet across to canvass the whole inventory of mid-80s Ford vans.

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Xylophoned!

I took a little time tonight to lay out a near-full keyboard on some telephone wire just to see how the 2-½-octave range sounded:

(video lost when we quit Facebook)

The keys don’t ring yet because there are no insulators under them, no holes drilled, no resonators to catch the sound yet, and it still needs a final tuning. But everything sounds solid so far.

Looks like I need to finish it up with a D at the high end. I’ll probably cut some more for the low end just because they sound so rich and I think I can keep going down before the metal’s native harmonics overwhelm each key’s primary tone.

On the subject of accomplishing things

Pride goeth before the fall, they say.

For a while there, I was having a proud day.

I had a DMV appointment at 10:40. By the time I waded through two jammed parking lots and landed out on Glenoaks, it was 10:52. But no problem, I sailed right through check-in, waited 10 minutes and was called to the window.

Bada-boom, bada-bing, I was out of there in 10 minutes with my license task done, the van registered – and instructions to get it smogged before I could get the full reg paperwork.

Straight to the smog shop near my house. The taciturn, ruddy smog-shopkeeper plugged the van into his gizmos, ran it through the paces and – bazoop – shot my PASS readings straight to Sacramento by wire. Happy day.

I jumped in. I had to wait a couple of minutes for the guy who had parked his truck abreast my tail to back out, but when he did, I managed to back out safely without nailing the gas pumps.

Quick head check, no traffic. I eased forward to the right around the island into a THOROUGHLY HORRENDOUS CRUNCHING NOISE and hit the brakes.

Yep. Peached it. Boy, I wish I had a recording of that sound.

I sideswiped a bollard at the end of the pump island. Hadn’t seen it below the level of this monster’s windows, and before I knew what I had done, it was too damn late.

The door still works properly but, well, I guess I know what I’m doing this weekend:

Pulling more stuff off of Xylovan’s dead twin at the junkyard. That’s what.