<Rumo>

an automated noise maker

Godfried-Willem RAES

2014-...



<Rumo>


This robot was named after Luigi Russolo, the most wellknown musician-member of the futurist movement at the start of the 20th century. Just like in his pretty primitive and purely mechanical designs, we make extensive use of acoustical amplifiers in this design. So, in a way, building further on principles highly developed during the period mechanical roll players and grammophones were developed. The sound sources used here are mainly springs, steel ribbons, membranes and rubbed strings.

It consists of a variety of very different non-pitched noise sources. Here is an overview:

1.-Excited spring with acoustic amplifier: This component uses a very long spring held between the anchor of an electromagnet at one side, and the membrane of an acoustic compressor at the other side. The acoustic compressor is coupled to a conical horn, in fact taken from an old bugle. The resonant frequency of the horn corresponds to midi note 56.

2. A second second sound source with similar excitation and membrane. For this one we modified a compressed air horn.

3. The third sound source is again a spring, but this time coupled to a brass membrane on a modified ships horn. The electromagnet used here is taken from a door closing mechanism.

4. A fourth horn, a linear cone in brass taken from an antique hooter, uses a smaller membrane again made of polyacetate.

5. A modified signal horn with a steel membrane, coupled to a very fine spring rubbed with a small DC motor.

6. Whisper components, using cavity resonators and individual fans.

7. A Nestor Martin coffee burner modified to make a rotary shaker.The handcrank was replaced with a DC motor and a dented driving belt: The drum can be freely filled with different materials: wooden balls, beans, rice, corn, stones, glass pearls... each material giving a different sound.

8. An industrial claxon horn. (24V - 800mA) sounding midi note 37/42. (C#, F#))

9. An automated hunting horn driven by a membrane compressor. This horn is suspended in a cradle and can move slowly up and down.[ removed from the <Rumo> robot and moved to the <Hunt> robot]



Midi implementation and mapping:


The midi channel <Rumo> listens to is 2. (If counting from 1, this would be channel 3).

the coffee roaster rattle is mapped on midi note 108. The velocity byte steers the speed of rotation of the drum. The ramping on speed changes can be controlled with two continuous controllers 32 and 33. Controller 32 is used to set the ramp-up time for acceleration and controller 33 for the ramp-down time for deceleration.

Lights:

note 120: tubular 24V/5W bulb on the horn assembly. The velo value steers the brightness.
note 121: Small 24V E24 bulb on the fixed part of the horn module.
note 126: Red rotating light. ON/OFF only

 

Controllers:

#1: Wind noise in the sound of the horn
#3: controller 3: Vibrato depth for the horn
#4: controller 4: vibrato speed for the horn
#5: controller 5: tremolo depth (amplitude modulation) for the horn
#6: controller 6: tremolo speed for the horn
#7: controller 7: volume control - global volume controller for the horn
#15: controller 15 - ADSR time scaling for the horn
#16: controller 16 - attack time controller for the horn
#17: controller 17 - attack level controller
#18: controller 18 - decay time controller
#19: controller 19 - release time controller for the horn (release time can also be controlled bith the release byte of a note-0ff command)
#20: controller 20 - tuning for the horn. By default A=440Hz for value 64.


#22: Movement of the hunting horn: 0-63 = downwards, 64-127 = upwards
#32: ramping up time for the coffee roaster rattle. Default value = 64.
#33: ramping down time for the coffee roaster rattle. Default value = 64.
#66: Power on / off. This command also resets all controllers to their default cold-boot values. Power off recalibrates the horn and brings it back to a central position.
#69: Enable or disable automation of the light on the horn. Default value : > 0, ON. To switch this off, send controller with value = 0.
#80: Dynamic range controller for the horn. Default is 64 for 40dB dynamic range.
#123: All notes off

pitch bend: range 1 semitone (-50 to + 50 cents) [note that pitch-bend must follow a note-on] Pitch bend is only implemented for the horn component.

  subject to changes during the building process 



Technical specifications:

Design and construction: dr.Godfried-Willem Raes (2014-2020)

Collaborators on the construction of this robot:



Music composed for <Rumo>:
none so far

 

This robot is projected to be ready by the end of 2020, if Godfried's health permits.

 

Back to Logos-Projects page : projects.html Back to Main Logos page:index.html To Godfried-Willem Raes personal homepage... To Instrument catalogue Naar Godfried-Willem Raes' homepage

Construction diary:

12.06.2014: Construction of the first electromagnet assembly. Testing of force and functionality.
13.06.2014: Construction of the acoustic amplifier with a horn. The membrane was made from polyacetate
14.06.2014: Welding of a holding construction for the horn and the driver electromagnet.
15.06.2014: Selection of suitable horns for the construction of more acousttic amplifiers.
16.06.2014: Construction of the membrane for a second acoustic amplifier. Design of the mounting.
17.06.2014: Discovered another identical electromagnet in our junk-yard. Mounting flange for the second horn welded. Horn re-assembled with the acoustic amplifier.
20.06.2014: Works on the construction of a thirth membrane amplifier, now using a thin brass membrane.
21.06.2014: Sketching of possibilities for an overall shape of the rumo robot.
22.06.2014: Another conical brass part found at the flea market. Useable for a linear horn and a small membrane. Silver soldering works on the combined structure. Orifice size for this one is 8 mm. The membrane could be polyacetate, steel or hard brass.
23.06.2014: Experiments with door closing electromagnets, as these have very high holding force. DC-Motor experiments for rubbing strings conducted as well.
24.06.2014: Mounting of the third horn assembly on the main structure. Electric tests: the electromagnet is designed for 12V (5W) at 100% duty cycle.

26.06.2014:Some new DC motors ordered from Farnell. Required for the spring rubbing mechanism. Work for <Rumo> slowed down a bit, as we needed to be working on <Zi>.
30.06.2014: Start of adding testcode in GMT. Further work on <Rumo> postponed, as we have to get on with <Zi> first... It looks like we cannot advance until at least november 2014...
13.09.2015: Time-space in sight to go on with the works on <Rumo>...
15.01.2016: As Logos lost all structural subsidy and thus all governmental support, further research work on musical robots becomes highly compromised. Corruption of the members of the advisary commitee that judged the case of the Logos Foundation was at the base of this tragedy. A feast it was for Blindman, I solisti del vento, Rosas, Victoria, Piet Van Bockstal, Ictus, Recto Verso...
23.05.2020: Start designing a PCB for a version using PWM-controlled fans only. Instead of replacing almost everything in <Whisper>, we consider to build a <Whisper-2> robot, maybe as a module of the <Rumo> project.
24.05.2020: PCB designed for the PWM-Fan version. The production of this PCB was not too succesfull as the film -made with our photocopier- was not black enough.
25.05.2020: PCB soldered. Some missing components ordered from Farnell.
26.05.2020: Firmware written for the newly made board. Waiting for the missing components. We cannot test and evaluate without them...
30.05.2020: PCB completed and programmed. First tests with the Sanyo 9GA0412P6G001 fans passed. Regulation is pretty good and seems stable and reliable. It's a pitty only, we do not have better resolution on the very low side of the PWM range. At the other hand, this was predictable from studying the air flow curves in datasheet.
01.06.2020: Construction on the lathe of some more and new cavity resonators.
02.06.2020: Tests and measurements using the Papst 8412N/2GHP 80x80 fan. The usefull PWM range (using 7-bits in our midi-interface) is 11 to 127. Below 11 the fan does not start running. The Papst datasheet does not give any information, neither with regard to the PWM frequency nor the control characteristics.
19.06.2020: Suitable tiger balsem box found on the flea market. Good for another size whisper unit.
20.06.2020: Project taken up again. Considering to integrate it with the design of a <Whisper 2> robot. PCB's etched for a hub board and a 12-output pulse-hold board.
21.06.2020: Hub board finished. Start drilling and soldering 12-output pulse/hold board.
22.06.2020: Soldering 12-output board. Here is a drawing for the placement of the wire bridges: Note that the bridges have to be soldered in place before any other component. Running into trouble: the P-channel mosfet, type BSP254A, is no longer on the market. This type was specified for -250V and Rdson = 10 Ohm. A possible replacement could be VP0109N3-G, but this type is only specified for -90V at 250mA and 6 Ohm. However, the specs are better than the BS250 part we have been using in late 20th century designs. BS250 had -45V, 180mA and 8 Ohm. Its getter harder to get discrete parts these days... Running out of IRL640 MOSFET's. New order placed at Farnell.
25.06.2020: A load of fresh IRL640 MOSFETS came is in we soldered the in right away.
26.06.2020: VP0109N3 P-channel mosfets soldered in, for test and evaluation. Do do this, however, we first should write some firmware...
27.06.2020: Preliminary version of firmware for the 12 output high voltage pulse-hold board written and tested. This framework is based on the coding for the percussion components in the <Per> robot.
30.06.2020: Two more whisper components made.
03.07.2020: Recalculation of component values in function of different negative pulse voltages.This is derived from the circuit as used for the <Per> robot. For the 10V zenerdiode we can select either a 1 W type or a 500mW type. In the first case, the zener current should be 10mA and in the latter case, 5 mA. Thus we can calculate a small table with values for Rzn for different values of -Vc:

-Vc Rzn 10mA Rzn 5mA
-12V 700 1k4
-15V 1k 2k
-24V 1k9 3k8
-30V 2k5 5k
-35V 3k 6k
-48V 4k3 8k6
-56V 5k1 10k2
-64V 5k9 11k8
-75V 7k 14k

For more negative values of -Vc, another power Mosfet has to be used instead of the IRF540 (100V max). Also be carefull not to exceed the 90V limit for the P-channel mosfet.
07.07.2020: Small diameter tin cans ordered from China, to make whisper mechanisms.
20.07.2020: Tin cans came in from China. Three different sizes, 12 pieces each, so we can perform experiments with different hole sizes.
27.07.2020: Furher work on the construction of more whisper components.
28.07.2020: Start of the construction of a 'windchest' or wooden mounting plate for the whisper components.
29.07.2020: Further work on the windchest: provisions and drilling for the mounting of the Sanyo fans.
28.08.2020: Work on <Rumo> taken up again: horns finished for all eigth whisper components.
29.08.2020: Two rings mounted on the wooden holder plate for the whispers. Eights Sanyo fans mounted and whispers test-mounted.
30.08.2020: Construction of a holder for the quad-PIC board for steering the Sanyo fans.
26.09.2020: Wiring of the whisper board and the fans.
28.09.2020: Considering to add a motor driven shaker, using an old coffee bean burner (Nestor Martin) filled with wooden beads. Searching for a suitable motor to drive this. Should be 120 rpm max.
30.09.2020: Crouzet motor ordered from RS-Components (Order nr. 224-3596). Here is a picture of the coffee burner: Designing a suitable motor controller for this thing. We can either use the design done for <Fa> (using a DCM24-40 controller) or the one for the low vibrato mechanism on the <Tubo> robot.
01.10.2020: The crank on the coffee burner connects with a 1/4" thread. So, we made some adapter pieces to couple it to the motor. The motor, a Crouzet 24V DC motor, came in from RS Components today. It has an 8mm shaft. This is the same type of motor as used for the low vibrato mechanism on the <Tubo> robot.
02.10.2020: Using the 1/4" thread did not lead to acceptable results. The lack of precision wherewith the coffee burner was made caused too much excentricity on the axle. So we decided to drill a 6 mm hole through the burner and mounted a dented wheel such that we can use a belt for driving the drum.
03.10.2020: First tentative mount of the chassis with the motor and first test of the complete mechanism.
04.10.2020: Further work on the coffee burner assembly.
05.10.2020: Going on with the coffee burner... Here is a PCB for the Crouzet motor-controller as well as a circuit drawing. This design is derived from our previous design for the same motor type used on the low vibrato mechanism of the <Tubo> robot. For the power supply of this unit, we can use a Traco Power module TMM60124 (24V - 2.5A). Etching, drilling and soldering of this board finished.
06-07.10.2020: Start coding firmware for the roaster. First tests... nothing seems to work. Oscillation of the board remedied by mounting a 100uH coil instead of the 22uH we had at first.
08.10.2020: Firmware for roaster ready. The bug we had was related to a limit on the amount of nested if-then structures in the proton code. This code implements ramping on speedup as well as on slowdown. PIC diary updated. A snapshot Moniek made of me whilst working on the roaster code: It makes an infernal noise...
09.10.2020: Industrial horn digged up: 24V - 800mA, sounding a C#, or midi 37. Bug removed from motor firmware: motor speed is no longer oscillating around the sollspeed value. All tests passed o.k. now.
10.10.2020: Start design of a suitable trolley. Maybe we can use nothing but wheelchair and rollator parts...
11.10.2020: Running out of stainless steel tube 22 x 2. Could we afford to buy new tubes or do we have to recycle? We are really running out of funds now...
13.10.2020: New stainless steel tube bought from Demar Lux...
17.10.2020: First design of the trolley.
18.10.2020: Start TIG welding works on the trolley: frontwheels mounted, the large backwheels -from an old wheelchair- are designed such hat they can also move sideways. Should we keep this feature? Dont know yet.
19.10.2020: Trying to connect again with the <Rumo> research started back in 2014. We certainly need many more sound sources in this robot.
20.10.2020: digged up an old hunting horn.
21.10.2020: Preliminary calculations and measurements with the horn. It sounds like it's a high f# tuned horn (probably an F or a G horn in some old diapason).
22.10.2020: More and more, it looks feasable, to add this horn in <Rumo>. Maybe we can use our amplifier design around the TDA7264 chip, as used for <Chi>:
There is even a PCB designed for this circuit:
23.10.2020: Het idee om een jachthoorn toe te voegen krijgt alsmaar meer vorm. We hebben al de hoorn, een PIC driverboard, een membaankompressor, een LM12 power-amp board en een geschikte voedingstransfo... Het LM12 board is hetzelfde dat we ook gebruikten voor <So> in versie 3.0. Het ontwerp en het PCB dateert van 1991. De vermogens opamp (LM12) is al lang niet meer verkrijgbaar.
24.10.2020: Voor de membraankompressor kunnen we het board gebruiken ontwikkeld na dat voor Autosax V5.0. Dat PCB is gedateerd 03.05.2020. Als driver kunnen we een oude Boyer (Frans) of een nieuwe Selenium driver (Brasilie) gebruiken. Op de foto hebben we de Selenium driver gemonteerd:
25.10.2020: Uittekenen mogelijk chassis voor de komponenten van de jachthoorn. Een draaibare opstelling -met motor- lijkt hier aangewezen.
26.10.2020: We ontdekten nog een Belimo LM24 motor module in ons labo. Dit lijkt wel bruikbaar voor de aandrijving van de beweging van de hoorn. Hier is het datablad van deze Zwitserse module. Test opstelling gemaakt: het mechanisme is marginaal sterk genoeg op de hoorn volledig op te heffen. De bewegingssnelheid is bijzonder laag: 80 tot 120 sekonden voor het gehele trajekt van 90 graden. Het mechanisme is wel zo goed als geruisloos. Bij een spanning van 24V DC is het stroomverbruik slechts 40mA. De volledige testopstelling op de lastafel ziet er nu zo uit:
27.10.2020: Verder TIG laswerk aan de ophanging en de mechanika voor de jachthoorn.
28.10.2020: Montage van de LM12 eindversterker en de voedingstransfo op geplooide inox plaat. Bruikbare Haller-relais opgedolven in het lab voor gebruik met de Belimo motor: Moeten we ook hier weer een Penny+Giles rotation sensor toepassen, zoals we deden voor <Ob>, <Klar> en <Fa>? Of, kunnen we met een 'eenvoudige' (maar vandaag illegale) kwikschakelaar volstaan? Zou het mogelijk zijn de eindposities af te leiden uit het stroomverbruik van de motor?
29.10.2020: M4 Tap afgebroken in de montageklem voor de hoorn... Schema voor de motorbesturingsprint uitgetekend. Dit printje is slechts 60 mm breed en past dus eventueel op het inox opstaand profiel van de hoorndrager. Een PCB voor deze schakeling is eveneens in voorbereiding:
30.10.2020: Verder werk aan de PCB's nodig voor de verdere afwerking/uitwerking van de <Rumo> robot. Hopelijk vallen we niet zonder essentiele onderdelen, want de kortzichtige en ongedifferencieerde corona maatregelen van de Belgische regering maken bevoorrading zo goed als onmogelijk.
31.10.2020: Produktie van twee PCB's: eentje voor de Belimo motorbesturing en eentje voor een TDA7264 mono-brugversterkertje. Beide samen passen on een eurokaart 160x100mm. De kwaliteit van de geetste printjes is ondermaats, vanwege de te geringe zwarting van onze printer... Dit is de gebruikte film:
01.11.2020: Opbouw van beide printjes. Korrekties aangebracht in de PCB files. Tests hardware. Hier is de bestukte print:
02.11.2020: Begin ontwikkeling kode van de besturing van de Belimo motor voor de beweging van de hoorn. De kalibratie zal, gezien de traagheid van de motor, wel behoorlijk wat tijd in beslag nemen na koude start en power-down kommando's.
03.11.2020: Versie 1.0 van de motorbesturingsfirmware is klaar. Hier ligt de print op de folterbank, gekoppeld aan de Tektronix oscilloskoop, de PC en de Pickit3 programmer van Microchip.
04.11.2020: Bestelling 24 V voedingsmodules bij Farnell: TMP60124. Bestelnummer 2280022.
05.11.2020: Werk stilgelegd omwille van het ondergaan van een PET/CT scan...
06.11.2020: Kwikschakelaar aangepast aan het 8mm uitsteeksel van de 20 mm as waarrond de hoorn kan draaien. Dit werkje volledig met de hand uitgevoerd, vanwege het risiko op breuk van de glazen kwikschakelaar zelf.
07.11.2020: Levering van de bestelde Traco Power voeding, 24 V - 2.5 A. Konstruktie van een chassisplaat voor de montage van deze voeding. Kablering van de motor, kwikschakelaar en kompressiedriver.
08.11.2020: Verdere bedrading hoorn module.
09.11.2020: Ontwikkeling 18F2525 kode voor debouncing (kontaktdenderonderdrukking) van de kwikschakelaar voor de motorbesturing van de hoorn. Eerste tests van de motorbesturing onder spanning. De motor blijkt niet te doen wat was voorspeld... hebben we een fout gemaakt in de bedrading van de relaisvoet? Grondig nazicht wijst uit: inderdaad, foutief genummerd op het printontwerp. Dit moeten we dus via een patch korrigeren. PCB ontwerp meteen ook gekorrigeerd zodat in toekomstige versies de fout niet opnieuw zou kunnen optreden.
10.11.2020: Montage van een 24V/5W buislampje op het bewegend deel van de hoorn. Test van de gekorrigeerde print voor de motorbesturing. Het blijkt goed te werken, maar... een van de aansluitdraden naar de kwikschakelaar kwam al te strak onder mechanische spanning te staan, waardoor de aansluiting naar de kwikschakelaar afbrak. Einde van de mooie antieke kwikschakelaar. Nu zit er niks anders op dan weer een Penny-Giles sensor (type STT280/60/P2) te gebruiken. Met de redaktie van de firmware moeten we nu natuurlijk ook helemaal herbeginnen.
11.11.2020: TIG microwelding works: mounting plate for the sensor on the 8 mm axle. Nieuwe versie van de firmware afgewerkt. De Penny+Giles sensor wordt nu gevoed uit de 5V DC spanning. Een 78L12 regulator op het PCB is daarmee overbodig geworden. Overweging om de hoorn module toch als een autonome robot verder te bouwen. Dit is een mogelijke wielbasis voor zo'n autonome jachthoorn robot:
12.11.2020: De kogel is door de kerk: de jachthoorn gaat alleen en verlaat het <rumo> projekt... Nu moeten we er natuurlijk een nieuwe naam voor verzinnen. Begin konstruktie van de wielbasis... we vallen echter zonder schutgas: Argon fles leeg. Onderkant van de basisplaat per vergissing gelast met gewone Hilco rood elektroden in plaats van met inox elektroden...
13.11.2020: Zoektocht naar alweer een nieuwe verdeler voor Argon gas. Zou <Hunt> een geschikte naam zijn voor deze robot?
14.11.2020: Nieuwe webpagina aangemaakt voor de nu zijn eigen gang gaande <Hunt> robot. Hier is de link. Buisklemmen met rubberinleg ingekocht bij Brico voor de assemblage van de diverse komponenten in Rumo.
07.12.2020: Bug gevonden en gedood in de kode voor de koffiebrander: Er zat een fout in het uitlezen van Timer 2/3, als 32 bit timer.

 

 

 


Maintenance information:

<Rumo> module

Electromagnets used for the two springs with acoustical membrane amplifiers: Grundig Radio Werke Gmbh, Relaismagnet 38/33. DC resistance: 55 Ohm. These components were taken from relays. They have a laminated core and thus can even be operated with AC..

Fans used for the whisper components: Sanyo 9GA0412P6G001 (these are variable speed PWM types!)

Crouzet motor power supply: Traco Power TMM60124, Farnell part nr. 2451695. Specs.: Medical, 24V - 2.5A. [used for the coffee roaster component]

<Hunt> module [no longer documented here. For current documentation use this link.

Belimo LM24 motor. [used for the hunting horn component]

Relay's on the Belimo motor control board: Haller-Relais, HB8-4-1B8-702, Spule 12V dc, kontakte: 28V dc or 115V ac, max. 30W.

The Belimo motor power supply used is another Traco Power TMM60124 module, same as used for the roaster.

Tubular light on the horn assembly: 24 V - 5 W

Penny+Giles tilt sensor [on the horn assembly]



Last update: 2020-12-07

by Godfried-Willem Raes

Further reading on this topic (some in dutch):


Technical data sheet, design calculations and maintenance instructions:

 


References: