[Nederlandstalige versie]

Robot: <Per>

In January 2018 we got a request from the Speelklok museum in Utrecht to make some of our robots available for a long running exhibition on musical robots. The robots they wanted to borrow were <Aeio>, <Bello>, <Bug>, <Pos> and... <Simba>. The loan came in as a perfect fit for the 50th anniversary of Logos. However, this placed us for a serious problem, <Simba> being used in an awful lot of orchestrations for our robot orchestra. Thus we decided to isolate the most frequently used components found in <Simba>, the hi-hat and the bell-rattle (tambourine) , and started designed a new robot that could replace these components and add some extra features as well. Thus <Per> was designed such that it could for the most part replace both <Simba> and <Troms>, a minimal drum kit as it were. As we are running out of space at Logos - at the time of this writing, the robot orchestra consists already of 72 musical robots - we decided to make it a robot to be suspended from the ceiling. Hence, it should not become too heavy. The idea of a flying drum kit also inspired us to develop a special Namuda production around it, to be premiered at the occasion of the festivities for the 50th anniversary of the Logos Foundation in our homebase in Ghent..

Here are some selected components:

For the tambourine we used 16 brass shell bells from an old orchestral tambourine dating from the beginning of the 20th century. In fact, the same shells as used for the <simba> robot. The design, although entirely new, follows the lines of the original instrument. Also we found back a small set of four Latin Percussion drums we once got as a present from a girlfriend: As these are miniatures, although very well made, they produce very high pitched drum sounds. The kit consists of a small conga, a darbukah and a pair of bongos. Designing a good sounding beater mechanism for these tiny instruments was not a trivial matter. The beater mechanisms we used hitherto didn't work very well and certainly couldn't compete with what human hands and fingers can produce. It's also worth to note that these drums use pretty thick natural skins and thus require quite some striking force. The best results we got after long experimenting sessions, was using flat blade springs as beaters. These springs we made from old metal saw blades. As the blade springs have to hit the drum membrane in a perfectly flat way, this idea can only be applied to drums not having a rim over their circumference. So it would not be applicable in a robot such as <Troms>.

The bass drum used here is in fact the other half of the bass drum we used for the <Troms> robot : Inside the bass drum we mounted a pedal beater using a hefty open solenoid with flying anchor, two twin beaters with piano hammers, a single rimshot beater as well as a large felt-covered damper driven by a linear push solenoid. A small cymbal, with a single beater, was mounted as well. A single crotale tuned to high B (midi note 95), made by Avedis Zyldian, was added as well. The cymbals were more of a problem as we did not have a pair of decent cymbals with equal diameters in stock... We bought a new set of Turkish cymbals. For the movement of these cymbals on the hi-hat mechanism, we found a heavy duty solenoid type - presumably made by Siemens - , but the anchor was missing. So we made a new anchor from very thick polished steel tube, in fact a recycled part from an old photocopier. The hi-hat assembly using these solenoids came out to look like this: To operate well, these solenoids require pretty high voltages. However, at 100% duty cycle the voltage must be limited to 40 V, as we found out by measurement (temperature rise over a long time in function of applied voltage). Thus we required a microprocessor controlled high voltage power supply. To keep things as simple and reliable as possible, we first tried to use a zero cross optical relay -internally using a triac - driving a rectifier and a quite hefty electrolytic capacitor.

This is the principle, drawn as a circuit diagram: We revisited an old and proven but quite primitive circuit principle: This is pretty easy to implement on a PIC controller, as long as the control pulses are longer than a full period of the mains frequency, 20 ms. Due to the long RC time realized with the large capacitors, we can go with very slow PWM. The solid state AC relay we used is MP240D4, as it's a zero-cross relay specified for 4 A at 280 Vac. The feedback-loop for voltage regulation makes use op an Optor, a resistive optocoupler. Instead of the pulse transformer driving the IGBT, an optocoupler can be used as well, but this requires a separated power supply, unless an esoteric high voltage optocoupler is used. Note that there always must be a load in this circuit, as otherwise output voltage will always be the peak voltage of the input. In practice however, this approach was abandoned because the loads -mostly short pulses- were way too irregular to make the voltage regulation work reliably. The result was clearly varying and unreliable velocity pulses on the solenoids. Thus we decided to go back to a very simple unregulated power supply providing +71 V and -71 V at some 250 VA, using a toroidal 2 x 50 V transformer, a rectifier bridge and two hefty capacitors.

We invested quite a lot of research time on the beater mechanisms used in this robot. First of all we wanted to improve on the beaters as we made them for <Troms>. The problem with <Troms>, using Laukhuff pallet valves for the beaters, was that the dynamic range goes down with decreasing size of the drums. Here we wanted to get a much more sharp and penetrating sound. As said above, we found that flat blade springs perform better in this respect than striking mechanisms using a ball head. However for the bass drum, we went a very different way and here we used solenoids with a fully free anchor. These behave very different than standard push or pull solenoids. When activated, the anchor moves to the magnetic central position and moving it from there requires a force proportional to the distance of the movement, up to half of the length of the anchor. So the behavior is a bit spring-like. When activated with the anchor one fourth of the length out of center, the anchor moves through the coil with an overshoot and then returns back to the central position. It's exactly this overshoot we use here for striking the drum. A light spring is used to return the anchor to an out-of-center position after a stroke. Without such a spring, further strokes would be impossible as the anchor wound start from the central and forceless position. The big advantage of this mechanism is that it guarantees an elastic stroke, as the anchor with the attached beater is basically free during the collision with the membrane of the drum. It goes at a price however: repetition speed is limited by the large inertia of the anchor and also, power efficiency is quite low. Mostly for visual reasons, we wanted the drums in a vertical position although from a pure functional point of view, a horizontal position would yield much better results and has the advantage that a return spring would not be needed and that friction would be minimized.

The damper on the bass drum was implemented in a much more refined way, compared to our <Troms> robot. First of all, the pressure of the damper against the skin can be controlled with the velo byte accompanying note 21. Pressure can be further modulated using the keypressure command for note 21 whilst the damper is activated. It is very important to know that the damper can use an overvoltage to obtain extra large forces. However, this cannot be done for a long time as the solenoid will get very hot. If users want to use the damper for an extended on-time (100% duty cycle) , the maximum value for velo as well as keypressure is 86. When the keypressure command for note 21 is issued without a note-on command, no velocity pulse will be applied to the solenoid. Thus it is possible to use the damper as a very soft beater on the bass drum. The velocity pulse produced at the reception of a note-on command can be controlled with controller #21. The default value for this controller is 1.

Calling this robot a 'flying' drum kit is a bit of an exaggeration. However, we did equip it with two motor driven propellers such that it is in fact capable of making gentle moves and swings when suspended on its hook. The motors are speed limited as we wanted to avoid serious accidents and injuries. The maximum speed is now ca. 1400 rpm whereas in order to develop substantial thrust, it ought to be at least some 8500 rpm. The propellers used are spare parts made for model aircraft's. The motors stem from an old professional Truvox reel-to-reel tape recorder.

The firmware for the two PIC microprocessors used was written in Proton Basic.

Circuit Overview:

• Hold velo / pulse boards:
• Midi hub board
: see bottom of page

Midi Mapping

Worked out, such as to have maximum compatibility with <Troms> and <Simba>

Midi implementation:

The midi channel for <Per> is 6 (0-15) or 7 (1-16).

Midi note range: 21 - 95., Velocity implemented to steer the attack force of the beaters, the hi-hat and the tambourine. For the lights, the velo-byte steers the flashing speed. note aftertouch (polyphonic) under development.

• note 120 : light inside bass drum
• note 121 : light inside bass drum
• note 122 : 1W red LED on the hub board
• note 123 : blue frontal lightbulb (velo byte steers the dimming here)

Note Off commands are not required for the drums, note release is not implemented. Note off is mandatory for the hi-hat. If you leave them on for too long, the solenoids get very hot.

Key pressure is implemented for automatic note repeats. The pressure value determines the repetition speed. Maximum repetition speed is 16Hz, but if such fast values are used, velocity values have to be kept at very low values. It is obvious that when the repetition length is shorter than the velocity pulse length, repetition will not work. Also, note that repeats using key pressure are 'sticky'. The setting is not canceled with a note off. So, once set all new note-on commands will lead to repeated notes, unless key pressure is set to zero again.

Note that as far as the damper is concerned (note 21), the key pressure controls the force exerted by the damper on the skin. Thus, pressure modulation is possible. Pressure values higher than 86 should be avoided. These higher values are only implemented to make short accents possible.

Controllers:

Controller #21 can be used to control the attack velocity of the damper. The default and reset value for this controller is value 1. At high values, the damper will operate as a soft beater on the bass drum.

Controller #30 is used to set repetition speed for all notes to one and the same value. The parameter determines the repetition speed. (Range 2Hz to 16Hz for values from 1 to 127). Repetitions start on reception of a note-on command. Thus, phase shifts of the repetition frequency will occur if notes are not started at the same time. This controller, with value 0 can also be used to cancel all repeats.

Controller #66 is used to switch the robot on or off. Switching the robot off, resets all controllers to their default values..

Controller #71: Controls the PWM value for the voltage during the velo-time on the hihat. Default and reset value is 64.

Controller #123: <Per> responds to the midi all-notes-off command. This command also switches off the lights.

Keypressure:

Note #21: Steers the pushing force of the damper against the drumskin. Safe maximum value = 86. Higher values can only be used for very short hold-times.

Note #71: Steers the hold force on the hihat cymbal during cymbal close. Default and reset value is 64.

Notes 120 to 122: Changes the flashing speed of the lights.

Technical specifications:

• size: width:740 mm, depth: 350 mm, height: 1630 mm
• weight: 36 kg
• this robot has to be suspended.
• Power: 230V ac - 100 W(peak)
• Sound pressure level: to be determined
• Ambitus: irrelevant as there are no pitched sounds.
• Insurance value: 12.000 Euro. (Production cost)

Design and construction: dr.Godfried-Willem Raes (2018)

Collaborators on the construction of this robot:

• Kristof Lauwers: GMT implementation
• Moniek Darge, donation of the LP drums
• Lara Van Wynsberghe, musical advisor
• Bert Vandekerckhove, workshop maintenance
• Johannes Taelman, code advisor
• Mattias Parent, workshop assistance
• Laura Maes, advisor and administration support

Music composed for <Per>:

• Godfried-Willem Raes "Ogiven", 08.2018 (a solo demonstration piece for <Per>) [mp4 video from this piece]
• Godfried-Willem Raes "Namuda Study #70: Poly", 09.2018
• Godfried-Willem Raes "PerOxyde", 11.2018
• Kristof Lauwers: Study for <Per>, 01.2019

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Nederlands:

Robot: <Per>

Er is geen Nederlandse beschrijving beschikbaar. Aangezien we geen strukturele erkenning en ondersteuning krijgen van de Vlaamse Gemeenschap zal daar ook niet meer aan gewerkt worden.

• 03.05.2018: Starting searching for required components as found on the <Simba> robot
• 04.05.2018: Construction of the bell rattle, using the same type of shells and wood as used for <Simba>
• 05.05.2018: Bass drum digged up, in fact the other half of the drum we used for the <Troms> robot. The inclusion of this drum entails a triangular construction, with a top angle of 30 degrees. This lay out, was our orienting point:
• 06.05.2018: Start welding works. Outside triangular frame with a top angle of 30 degrees. Mount for the tambourine solenoid welded in place. Circular bounce place welded in place. The pair of bongo's tentatively mounted. The vibration absorbers used are too soft, so this problem is to be solved.
• 07.05.2018: Further work on the mounting of the three highest drums. Recycled saw blades used as beaters, after many experiments, yield the best result. The miniature conga is more of a problem, as the opening is too small for our hands, thus making it very hard to find a way of fixing them on the structure. Also this drum is rather high... Solenoids selected for the highest drums. We will use 24V types here, and drive them with 80 to 120V dc pulses. Considering to mount a small propellor and a motor to cause the instrument to move.
• 08.05.2018: Welding of the first couple of solenoid holders for the top drums. The third drum, the Latin Percussion wood darbukah, requires an L shaped standoff. Three solenoids mounted with flat sawblade beaters. This is how far we got with it today:
• 09.05.2018: Mounting of the regular darbukah (short M10 bolt) and the miniature in aluminum (M8 x 20 bolt). Solenoid holder for the large darbukah welded. We are slowly running out of argon gas though. With these five drums, that should be it for the drums. We could add lights inside the drums...
• 10.05.2018: Further construction works. Vibration absorbers ordered from Farnell. Mounting of the bass drum worked out.
• 11.05.2018: Design of the beater mechanism for the bass drum. Mounting plate drilled for circuitry.
• 12.05.2018: Mount for the bass beater constructed. Tests with an external power supply.
• 13.05.2018: Recycling a solenoid mechanism from a Funke railway electric bell, a left over from the construction of our <Bello> robot. Beater turned on the lathe. This assembly may be used for the rimshots on the bass drum. It has an internal return spring as well as an end stop. The M8 MF shock absorbers ordered from Farnell came in, thus the bass drum can be mounted on the chassis.
• 14.05.2018: Welding and construction works halted as we are running out of Argon gas. That's quite expensive.
• 15.05.2018: Decided to use this machine as the central part for our Namuda production with Tashi Iwaoka and Emilie De Vlam to be premiered on the occasion of the festivities around the 50th anniversary of Logos. Production costs -in part- added to the grant request to the Flemish government. This involves a risk, as the vast majority of members in the advisory boards appear to be strongly opposed to robotics in music...
• 19.05.2018: Further research performed on the large free-anchor solenoids. The force versus displacement function looks like a bimodal distribution: The horizontal axis is not drawn to scale. The force is a function of the current flowing through the solenoid and this current is also a function of the position of the anchor. This is easy to understand as the inductance of the solenoid will be at maximum when the anchor is fully inside the coil, hence in this position the current will be at minimum. Current will be at maximum when the anchor is fully pulled out of the solenoid. The springlike behavior of the anchor when its in a central position is clear from the curve. We still have to measure the forces in standard units, say Newton. The shape of the curve is a mere first hypothesis. Force = Sin (Pi.s).Ic could also be a workable approximation.
• 20.05.2018: As we have fresh argon gas, welding can continue: support bracket for the 5th drum, the small darbukah, welded on. Continued work on the development of the hi-hat mechanism. With the open solenoids we noticed movement starts at about 40 V and the cymbal is fully lifted at 60 V. Forces become more substantial at 100 V. However, at 60 V the duty cycle cannot be 100%, so we have to take this into account when developing the firmware. Confronted with problems of available space, as our prototype does not fit between the bottom plate of the drum assembly and the upperside of the bass drum...
• 21.05.2018: Redesigning the hi-hat mechanism, such that it can be mounted within the constraints of available space. 200 mm x 180 mm plate, 2 mm thick bend to fit the curvature of the bass drum. This plate should hold the hi-hat assembly. Pass through holes and mounting holes drilled. Attachment for the solenoid holder welded on the plate. Holes in the bass drum drilled to size. First tentative mount of the hi-hat on the bass drum. Alignment fault is now 10 mm. To be adjusted. This is the first mount: We still have to construct the third point of attachment for the bass drum. This could be a 30 x 3 length of flat stainless steel, welded on the sides and with a M10 mounting hole to fit the solenoid bracket's internal thread.
• 22.05.2018: Cross bar bent for third point attachment of the bassdrum and TIG welded to the frame. The 10 mm error is corrected now and the cymbals are in line. Reinforcement plates drilled (12 mm) and welded on the top.
• 23.05.2018: Chassis part for the mains power inlet and the midi-input connector made and welded on the top part of the structure. By positioning it there, we minimize the risk of getting in trouble with tangled wires when the robot starts moving around its suspension point. Making the connections however, will require a ladder... Further work on the large bass drum beater. In need of an M10 bolt in nylon or aluminum...
• 24.05.2018: Further work on <Per> halted as we first have to weld the 'singing fence' project to the order of Frederik Van Simaey...
• 05.06.2018: Two potentially useable AC induction motors digged up for driving the propellers. These stem from an old Truvox professional 3-motor tape recorder. Axle diameter is 4.68 mm, a weird size. Presumably 3/16"... British.
• 06.06.2018: All eight bolts holding the motors together changed for metric M4 types. Distance holders, 20 mm M4 thread (FF) hexagonal mounted. We still don't know how to securely mount the propellers.
• 08.06.2018: Propellers and axle mounts ordered from Conrad came in.
• 09.06.2018: Start construction of the propeller mounts. Two motors fixed on the chassis. Propellers mounted and tested O.K. Looks like we can use the code section developed for the <Pos> radial compressor to steer these two motors properly. The motors run on 230 V ac and blocking them poses absolutely no problem.
• 10.06.2018: Further work on the adjustments of the propellers. Changing the direction of rotation is impossible with these motors. One turns left, CW, the other right, CCW.
• 21.06.2018: Sawblade fingers on the lowest darbukah:
• 22.06.2018: <Per> suspended:
• 24.06.2018: Mounting of the rimshot beater inside the bass drum. This solenoid is a recycled part taken from a Funke railway bell. It's capable of very fast repeats. Mounting of the pedal bass beater:
• 27.06.2018: Construction of a twin beater assembly for the bass drum: Here we use recycled piano hammers mounted on a solenoid.
• 28.06.2018: Design of an automated damper mechanism for the bass drum. 24 V push type 14 W solenoids ordered from Conrad.
• 02.07.2018: Construction of the damper mechanism.
• 04.07.2018: Adding lights inside the bass drum
• 09.07.2018: Construction of the left side cymbal beater (mid cymbal beater)
• 10.07.2018: Construction of the right side cymbal beater (edge beater)
• 12.07.2018: Remounting of the bass drum skin, with text upside down. Further work on the design of the hub PCB.
• 22.07.2018: Design of a suitable power supply.
• 23.07.2018: First high voltage power supply assembly finished:
• 26.07.2018: PCB design for the hub board finalized. This is the circuit:
• 27.07.2018: Finalizing the PCB for the bug board. Etching and drilling. This is the PCB:
• 28.07.2018: Soldering of the hub board. Here is a picture of the soldered board: Start coding for this newly made board. Here we will use a Microchip 18F2620 processor. The implementation of the propellor motor control should be similar to the code developed and tested on <Pos> earlier this year. The hub-board takes care of the two propeller motors, the rimshot beater, the damper, the twin beaters the 1W on board bright red LED and the two 12V bulbs inside the bass-drum.
• 29.07.2018: First version of the firmware for the hub board. A plethora of problems appear to show up...
• 30.07.2018: A full day of firmware debugging... Test code in GMT added. Per implemented under GMT.
• 31.07.2018: Cold testing of the hub PCB done. Passed all tests under lab condition, without solenoids and lights connected.
• 01.08.2018: For the small drums, the hihat and the tambourine we can use the high voltage 12-output pulse-hold board we designed 08.2014. This is the PCB: Note that common anode diodes in TO220 packages are used in this circuit. The pulse/hold detail is: This circuit is applied 12 times on the PCB. Here is the assembled PCB: Start writing the firmware for this board.
• 02.08.2018: Version 1.0 firmware uploaded in both microprocessors. Start wiring of solenoids and components. All small drums as well as the tambourine done.
• 03.08.2018: Continued wiring. Propeller wiring finished.
• 04-08.08.2018: and more wiring...
• 09.08.2018: Welding en drilling of the back plate (60 mm x 4 mm). Further wiring.
• 10.08.2018: Finalisation of the wiring. First tests can start... And, indeed, it played it's very first notes today. Now we can start optimalisation of the velocity scaling and mechanical adjustments. Only the pedal beater seems to have a problem.
• 11.08.2018: None of the velo-bits on the pulse/hold board seem to be working. Did we burn all MOSFETS by accidentally reversing the power polarity? On the hub board, everything seems working. We implemented key pressure for the damper as well as ctrl #21 for the attack pulse.
• 12.08.2018: Thorough checking of the velo-section on the pulse-hold board. Functionally OK, but we discovered the IRF540 mosfet's on the board cannot handle voltages over 100 V. So, we replaced the IRF540's on the outputs using the velo pulse (out 1 and out 6) with IRF620 (200 V/5 A) types. The BSP245 P-channel mosfets are specified for 250 V. As quite some IRF540's seemed burned out, we removed all of them from the board. As the solenoid for the mid cymbal beater burned out, we replaced it with a 12 V type and a 30 Ohm series resistor (in fact two 15 Ohm / 10 W resistors in series).
• 13.08.2018: Small cymbal and a B crotale (midi note 95) added. Firmware upgraded accordingly. The crotale needs a more elastic suspension and probably a heavier beater.
• 14.08.2018: Power connector mounted. Note that we used a 13 A socket and plug, with horizontal contacts and not the regular IEC connectors:
• 15.08.2018: Hook made for the suspension of the robot. First preliminary public demonstration of the robot.
• 16.08.2018: Beater mechanism and suspension for the crotale improved. Now isolated from chassis with M4 male-male bobbin mounts and felt. Beater now uses a blade spring and a brass decorative nut. This nut has an UNF thread...
• 17.08.2018: Test software in GMT upgraded. Bolts and nuts secured. This is the new beater mechanism for the crotale: Note the blade spring and the brass beater. An elastic mount for the crotale is essential for a good sound.
• 18.08.2018: 1 mm thick silicone washer added on the damper solenoid. Suspending hook mounted. <Per> is fully operational now.
• 20-22.08.2018: Composing 'Ogiven', a pretty nice solo demonstration piece for <Per>
• 17.09.2018: Interactive code written for <Per>: Namuda study #70.
• 18.09.2018: <Per> suspended in the Logos Tetrahedron with assistence from Mattias Parent. Its weight is 36 kg. Testing can take off.
• 20.08.2018: First public try out for <Per>: Namuda Study #70 and 'Ogiven'.
• 21.08.2018: The <Per> robot, although already functional now, is projected to be fully operational before September 22nd 2018, just in time to replace <Simba> in the robot orchestra..
• 23.09.2018: Further exploration of the possibilities.
• 07.11.2018: Namuda Study #71, Rational Melodies, has an important part for the <Per> robot. Rehearsal sessions with Emilie De Vlam.
• 10.11.2018: Premiere of Namuda Study #71, with Emilie De Vlam
• 25.01.2019: Lamps inside bass drum replaced with LED light using a self constructed E14 adapter socket.
• 30.04.2019: Hi-hat mechanism improved: the central threaded rod replaced with a nylon rod, thus saving weight and gaining pressing force on the cymbal. Cymbal positions readjusted and felt rings replaced.
• 02.05.2019: <Per> on the road to Koeln, for a WDR broadcast and concert with Sebastian Graems.
• 06.05.2019: Return from Koeln. Fixing some loose bolts required.
• 30.07.2019: On its returm from Tomorrowland, one of the drum beaters got loose. Also, due to the high humidity, the drums with natural skins didn't sound as the should. Drying will be the cure.
• 02.05.2020: Adjustment of the beaters and the drum positions. Full check-out. <Per> found to be o.k.
• 21.07.2022: One of the beaters on the hi-hat broke off in the Satie production, Sports et Divertissements.
• 29.07.2022: High-hat beater repaired. Solenoid assembly replaced. <Per> is in perfect shape again.
  
• 02.10.2023: <Per> returned safely from its appearence at the Deutsche Oper Berlin for the 'Zeroth Law' production.

To be done

• Construction of a light flightcase, as this machine cannot stand on its own.

Robodies Pictures with <Per>:

'Peroxide' performance, 10.11.2018

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Last update: 2023-10-05 by Godfried-Willem Raes

Technical data sheet and maintenance instructions:

• PIC controllers: 1 x Microchip 18F2620, 1 x 18F4620
• Power supply:
  • Hold voltage: 71 V / 2 A
  • Lights voltage: 12 V / 830 mA, smps on the hub board.
  • Velo pulse voltage: 71V / 2A
  • Logic 5 V / 2 A supply: on the midihub board.
• Label text on the Siemens solenoids: (12) 62-4200-0l.42 CuL, Siemens production number: V30041-X3022-X. These solenoids were a gift to us from our colleague Christoph Schlaegel. The encapsulation in 50 mm stainless steel shells was added by us.
• August Laukhuff 24 V small pallet valves. Rdc = 228 Ohm. At 100% duty cycle, these draw 100mA and P=2.4 W. Using these on 70 V, yields I= 300 mA and P=21 W, so to play safe the duty cycle should be limited to 10%. Max. pulse width become ca. 10 ms.
• Weigth: 36 kg
• Propellers: APC 15X8E LP15080E, Conrad order nr. 1369978
• Propeller mounts: Reely, 5 mm diameter axle, Conrad order nr. 233186
• Propeller motors: Truvox, UK. (one motor turns CW, the other CCW. 240V ac)
• Toroidal transformer 250 VA 2 x 50 V, Farnell order nr.9530886, Type MCTA250/50
• Mains power connector: not a regular IEC 3-prong type! Must use a Bulgin PX0599 plug and PX0596 socket (16 A / 240 V).
• Wiring table for the PIC 18F4620 controller board:

• Wiring table for the PIC 18F2620 controller board:

PIC processor firmware:

• - Hub board: source-code and hex-dump for the 18F2620 processor
• - Pulse/hold board: source-code and hex-dump for the 18F4620 processor

Disassembly and servicing instructions:

This robot uses drums with mostly natural skins. Hence it has to be protected from moisture. For servicing, the robot can be but flat on either frame side. Do not stand it on the bass drum for a long time. Before adjusting any mechanical parts, make sure the power supply cable is fully disconnected. After disconnecting wait five minutes to allow the capacitors to discharge. This robot uses quite high voltages and hence touching parts involves a risk.

Cost Calculation for this building project:

On the original budget but not yet expended:

Labor

calculation based on 273 Euro/day, which is the wage cost derived from our payrolls in 2017.

(Invoiced by self employed collaborators Bert Vandekerckhove, Johannes Taelman a/o.)

Total estimated cost: 9.388 Euro