Calliope News

OK, gang, bottom line: the damned thing works and it’s time for me to get off my fat ass and start writing up the details. The rush to get the thing done and working B4 Maker Fair meant the thing was, to a certain extent, not the ‘preferred embodiment’, but now I’ve got a feel for what that entails and I’m going about making the mods to achieve this.

At the end of this description I’ll copy-and-paste the flyer I made that I was handing out at Maker Fair and RoboGames earlier this month.

Soooo there are three major widgets that make it all happen: whistles, electronics and software. The whistles are, indeed, Helmholz resonators and they will toot with an amazingly low pressure; i.e. around 2psi is plenty. Up until yesterday I’d needed an air compressor supplying 80psi to the whistle manifold due to the nature of the solenoid valves I had been using for the project. These were designed to operate at up to 10,000psi (!!) and had a narrowing, or aperture, measuring only 0.052″ dia (a #55 drill was a close fit) where the valve piston seated. Just for grins, now that the rush was over, I disassembled one of the solenoid valves and had a go at enlarging this aperture. I didn’t want to have to go the whole nine yards, enlarging the diameter of the piston from .125″ to something else, then boring out its guide, etc so I selected a diameter that was less than said piston to see if I got lucky. Indeed I did!

Doing the math I determined that enlarging the orifice to 0.1015″ (a #38 drill) would quadruple the surface area of the aperture and, to my surprise and delight, this dropped the manifold pressure needed to toot a whistle to exactly one quarter of what was needed before; i.e. now instead of 80psi, it works on 20psi, woohoo! Doing the same to all 12 valves took several hours; managed to bugger up one but I got out one of the 4 spares and got that one right, so I’ve got a full octave of 12 now back on the manifold.

Took the opportunity and roughly tuned all of the whistles, as several had gotten badly detuned by being rattled around in the truck these past weeks.

As for electronics Kris and I were both fairly short on time so she managed to organize prototype electronics into a really elegant little board and got several of them printed up at PCB Express. I did the soldering and then there was a ton of wiring; it’s amazing how long it takes just to connect the dots: days! One problem surfaced pretty quickly: although all of the holes were in the right place we had neglected to add a connector for a programming interface cable! We worked around this by replacing the standard Stamp socket with a ZIF Stamp connector (5 day delay to get ’em mail order, SOP, yes?). Once installed the ZIF slots were roomy enough that there was room not only for the Stamp but also room for a cobbled-together 4-pin ribbon cable connector adjacent to the pins that needed to receive the signals.

All was made tidy and secure inside a model car display box (TAP Plastics: cheap) with the addition of a little hot glue on the ribbon cable where it had to pass thru the box and the system was ready for prime time.
Now that the public events are behind us it’s time to start thinking about version two of the circuit board. For starters it will be larger, if only to accommodate standoff in its four corners (early version had to be double-taped to a block of wood!). There will also be a serial cable connector to get data into onboard memory. The final change will be to add a pair of numbered thumbwheels and a pushbutton so that as many as 100 tunes may be stored and retrieved without recourse to a laptop.

Back on the workbench at long last I wrote a little ‘play scale’ program to help in tuning, but the first thing I noticed is that for some reason I’ve yet to fathom, the lowest note won’t play. I suspect the problem is somewhere in the wiring but I’ve yet to find the source of this problem. Tunes seem to play fine but there are only 11 of the 12 whistles playing.

Once the laptop is superfluous (except for initial loading of tunes) I’m thinking we’ve got a product of sorts.
Which brings us to software. Kris has tweaked the basic Parallax ringtone converter program with the lookup table that converts ringtones to pin out commands and it works a treat.

Now that the learning curve is beginning to level out a bit I’m beginning to think it might be possible to go back and reexamine earlier, smaller versions of the calliope with an eye to making that desktop executive toy viable at long last. A little more work B4 we’re there but the idea tantalizes, hehe.

I’ll add photos when I remember how to add ’em…
———————–
Steamboat Ed’s
Aetheric Musical Machine
Calliopus Minimus
The Ringtone Wrangler
Project Participants:
Concept & construction: “Steamboat Ed” Haas
Driver Board design: Kris Magri

The Toot-orial
These whistles are technically known as “Helmholz resonators”, chosen only because I discovered an excellent tutorial describing them on the web.

If you’d like to build your own there are photos and text of my build.

These whistles are activated with solenoid valves. These valves came via barter, which is to say they’re not ideal but they were good enough; ya get what ya pay for, eh? The solenoid valves are *explosion-proof and thereby hangs another tale. When buying solenoid valves try to get ones rated for low pressure, with the largest diameter internal passages you can. Larger passages permit lower manifold pressure and a smaller air compressor can be used to make the whistles toot properly. There are many retailers of solenoid valves; here are two well known ones:

• Big stuff: –Parker
• Small stuff: –Clippard

Tuning was done with a downloadable program called Chromatia Tuner, available for $19.95 from: http://www.fmjsoft.com/ctframe.html

-To know what note to tune to, you need a table of frequencies for each octave. Here’s a link to one.
-There is a pile of useful acoustic formulae and other files on the Yahoo Whistle Forum.

Control is via Basic Stamp, model BS2. Parallax has easily the best documentation and the best primer available for any microprocessor. I highly recommend the book, “What’s a Microcontroller?”, which comes bundled with a Basic Stamp, the “Board of Education” (their prototyping board) and a kit of parts.

Tunes are NOT MIDI, but RTTTL; i.e. the Ring Tone Text Transfer Language, which tend to be written for limited octave range and which tend to be short, thus conserving compressed air. More on RTTTL can be found via google, but be sure to look for tunes in the nokring format. One good source of tunes I’m mining is here.

Software to use a Stamp to translate RTTTL text files into something that can activate solenoids or other devices requiring high power and FETs can be downloaded from the Parallax forum thread.

The Solenoid Driver Board interfaces between Stamp and Solenoid valves. Each of its 12 channels can run either a solenoid or a motor rated up to 2 amps at 24v A much improved version of this board will be available shortly. Following is a schematic of the original board if you’re feeling ambitious and want to build your own (!!). If you want to buy a board send email to: calliope@nmpproducts.com and we’ll let you know when they become available.

Bibliography:
-“A Steam Calliopette” by LBSC, Model Enginer Vol 107, #2682
-“Calliope” by Conrad Milster, Live Steam, Jan-Oct, 2003

*With explosion-proof valves I have the option of running the calliope on propane, bwahaha.

April Adventures

     Gotta start writing it down so’s I don’t forget it, being as so much has been happening over the past week. Santa Barbara from Thursday to Tuesday, then cannon shooting this past Saturday!
     SB in two words: Barnacles and Bowling
     Cannon shooting in two words: Kaboom! and Yeehaw!
     One of the bigger reasons why I left SB: most of my productive pals were already living in the Bay Area. I had a minority of sedntary pals in SB and most of us managed to get together at the good ol’ Bay Café one night I was down that way. SB is such a little slice of paradise, in terms of city size and weather that people go there and then never want to leave. Hence: barnacles. Of those eight or so individuals at the dinner table only one of them has, in ten years, ever come to visit me, or anyone else, I expect, who lives away from SB.
     As for Bowling our proximity to the Southland meant Judy’s youngest daughter Serena, her hubby Jerry (curiously we have 3 with that name in the two branches of the family) and their two kids Jazmine (we’ve got two of them too!) and JJ could come hang out with us for a few days. It was a wild time and we enjoyed it from beginning to end. Many fun moments but the one that sticks in my mind was being dragged kicking and screaming out to the local bowling alley. I hadn’t been bowling in 45 years but there I was, wearing those silly slippery oversized clown shoes, sliding around with the best of them. Fortunately the kiddy barriers were up for the wee ones or we would have been in real trouble! I think just about every one of us made a ‘bank shot’ or two, to great effect. In all I fell down twice (shoes radically oversize), got two spares (one a bank shot!) and two strikes so I broke 100, woohoo!
One more adventure was purely culinary: a total pig-out at Woody’s BBQ, nummy nums! Much gooiness and the best BBQ sauce in SB.
     Absent from the list of interesting things was my reason for going: WESTEC, which was a total bust. Absent from the play card were many of the ‘regulars’ including Bridgeport, all of the pretty girls handing out stuff, stuff to hand out: NO zero zip nada free samples! My biggest score was after the event at Harbor Freight in Camarillo where I was able to pick up a tubing ring roller that I’d been unable to obtain from their local store or from their webpage, for six months of increasingly frustrated dealings.
     And then we come to Kaboom! This Saturday April 4 was the occasion of Bruce Heppler’s annual April Fools Cannon Shoot. It’s a real trek for most folks; 2-1/2 hours of driving, including 26 miles of windy road from 101 to Round Valley and the town of Covelo, CA.
     It was my third trek to this event and the first one where I was able to get the whole experience. That is to say that like several fellow diehards I arrived the previous evening and was treated to their most excellent hospitality which began with a dinner featuring a home-grown home-cooked ham that tasted sooooo much better than any hormone- and water-injected beast you’d find at the market. Got to sleep in a real bed so sleeping bag not required and I even wound up with a ‘heater cat’ who purred the night away; very pleasant. Didja ever sleep so deep that you wake up drooling?
     Next day bright and early I staggered to consciousness only to find Bruce had been up long enough to stoke the fire (his design: very efficient woodstove) and he’d started to get together all of the tackle we’d need for a successful outing. I staggered out to find Janet had heaped plates with pancakes and sausage; so much for the diet, hehe. Janet hobbled around the kitchen cooking up a storm; said hobbling induced a few days back by a ram who was a bit ornery; it’s a tough life they lead. Bruce is machinist, weldor and lately artist. Janet’s a shepherd for a huge flock of sheep, goats and other fauna.
     We loaded up and drove the 15 miles to the shootin’ range, a road that gets progressively worse and very innnteresting from the standpoint of a guy without 4-wheel drive! Finally we arrived at the site and it was perfect. Just enough moisture left in the soil and plenty of greenery so we wouldn’t start any uncontrollable fires. Learned a few interesting facts while I was there. Didja know that people are racing 3/4 scale stagecoaches and that all of the spoked wheels seem to be made by one blacksmith in Chico? Didja know that, in a pinch, you could mash up Cheetos and add ‘em to scrambled eggs to make them more cheesy? Another guy, a volunteer fireman (there were several in our mob) noted that Cheetos burn in a very peculiar way, too (gotta try that one!). And that set the tone for the day: totally crazy and a whole lotta fun. In all there were 8 ‘field pieces’ ranging from .50 cal to 90 mm bore, plus an undetermined number of blackpowder firearms ranging from .50 to .75 cal. I’d say throughout the day we got off more than a hundred shots with the big guns and probably the same with the handheld artillery. I had one powder bag glitch but it still fired every time I lit the fuze, which is more than I can say for some others. There were three or four hang-fire episodes but they were all handled with the utmost caution and with the kind of experts in our midst there were no ‘incidents’, heh. There was one instance worth noting: a mortar had been affixed to a beautiful, beefy oak cradle but one of the major components had been designed with the grain running the wrong way. Sure enough, on maybe his 5th or 6th shot the cradle split down the middle in a quite spectacular display, all captured on video!
There were many really excellent marksmen in our midst but I wasn’t one of them! It wasn’t until my 5th shot that I actually witnessed the projectile hitting the hillside in the distance and that was my first chance to adjust my sights. Looks like it got more than a little jostled in the past year: I was off about 40 clicks in azimuth and elevation! Made an adjustment or three (one in the wrong direction I suspect; I was a little rusty, heh) and it was several more shots before I realized the problem when I succeeded in trimming a *very* hefty branch from a tree in the distance! We ended the day with a fantastic volley and I would have captured it all on video except for the doofus who stood in front of the camera; oh well, there’s always next year. Yeehaw!
     Current work, postponed for these events and becoming urgent: my old wooden-frame outfeed table for tablesaw has been falling apart due to heavy loads and conversion to an erzats welding table; gotta make me a real one out of steel, with a 1/4” thick slab of steel on top. All else is on hold ‘til that’s done. Once done it’s back onto the calliope, which has been approved for exhibition at Makers Faire, woohoo!
More stuff happening not to be missed:
April 26: Pacific Coast Dream Machine Show
May 29-30: Makers Faire at San Mateo County Fairgrounds
May ?? Fire Arts Festival at The Crucible
?? Open Day at the Penngrove Power and Implement Museum
August 15-16: Pacific Coast Air Museum Air Show
Aug/Sept Burning Man
Late Sept Great Delta Steamboat Meet
?? ???
Yes a fun Spring and Summer, woohoo!