THE BLACK CAULDRON
MONDO Poster Art for OH MY DISNEY show by Francesco Francavilla
The SHow opened 15 min ago so I can finally reveal my contribution to the Mondo/Disney gallery: THE BLACK CAULDRON.
ScreenPrint is 24x36”, not sure on the print run and pricing yet. If there will be leftovers from the show, Mondo is gonna put them online.
I’m getting some Artist Proofs which I plan to remarque. Will let you know details when I get them :)
The Pinball Clock (Part 1)
The clock is made from an old electro-mechanical pinball machine (a 1975 Chicago Coin Red Baron http://www.ipdb.org/machine.cgi?id=1933). All the visible parts are pinball parts, including the case, lights, and feet.
Quick tour: starting from the left, the first four score reels show the hour and minutes. Then there’s a ‘credit reel’ (with thirty clicks) showing the seconds in 2 second steps. In the front center are two ‘spinners’ which are connected to latching relays (originally part of the internal logic of the machine). The left spinner flips around to show AM or PM and the right spinner shows sunrise / sunset (based on the clock’s geographical location and calendar). On top of the spinner’s frame is a star-post which changes color to show system status. In the very center, behind and between the spinners, is the year indicator (a six digit total-hours-played meter from the inside of the machine). To the right of that is the bank of three chimes, a three note wood/aluminum xylophone triggered by solenoid hammers. Tucked away under the chimes (but still visible) are two relays and a fuse bank used to route power to the solenoid coils. Finally the right four score reels show the month and day.
Internally, the clock is controlled by an Arduino Mega. The Arduino controls eight logic-level power MOSFETs , controlling the power to the 24VDC solenoids. The solenoids are arranged as matrix of four banks of six, with two relays controlling the bank-selection ‘high side’ voltage output and six ‘ground return’ MOSFETs (the remaining two MOSFETs are dedicated to controlling the two high side relays) This arrangement supports to 24 solenoids, of which 13 are currently used. This arrangement also means that the 24V power is not live on any of the exposed wiring except when a solenoid is firing. Each solenoid has three SMD blue LEDs that flash when the solenoid fires, providing feedback and a nice 'spark' effect.
…cont’d in Part 2
Pinball Clock Part 2
The score reels have a circuit board and “sweeper” contacts that rotate along with the reel. At the zero position, the sweepers open a switch contact, allowing the Arduino to detect the reel is at zero. Once it knows where the reel zero position is, it counts the number of times it fires to tracks the currently displayed number (reels can only single-step forward, not backwards). At startup, the system pulses all the reels until they are all at zero, so it has a known starting position. It also logs if it takes more or less than the expected 10 pulses to make one complete revolution and return to the zero position, so it can detect physical problems with the reel advancing.
The spinners use ‘latching relays’ which are a pair of relays arranged so they lock into one of two positions without needing power after they’ve locked. This lets the spinners show two states (that change infrequently) without needing to keep the relays powered continuously. These have no feedback of their state, so the system fires both relays once on startup to set them to a known state.
The year relay has no feedback, but it only fires once a year, so I’m OK with that.
The three chimes are programmed to ‘bing’ every hour — calling out the hour and with special sequences for midnight and noon. There’s a ‘volume’ control knob which adjusts the power to the chime hammers, allowing them to be loud, quiet or muted.
There’s a red metal button, front and center (originally used to trigger a flipper), which is used to switch between normal, no-seconds-tick, and mute / disabled mode. Double tapping the button will start a self-test mode.
IT’S VERY LOUD.
The hour and minutes solenoids have been ‘muted’ using Sorbothane bumpers, which drastically reduces the amount of noise they make. The seconds reel has also been muted, but the escapement mechanism is just louder overall , so there’s an option to stop the seconds reel from moving. However, without the steady tick-tick of the seconds, the minutes reel advancing can be a little startling. I added a quiet ‘click click click’ warning sound effect for one second before the minute reel moves, which is enough to give your brain warning and you don’t jump.
The light sockets are powered by an adjustable DC-DC buck supply, currently set to 7 VDC. The BA9 mini bayonet sockets are original to the pinball machine, but the light bulbs are replaced with warm LEDs for efficiency (they look very similar to the original type 44/47 bulbs)
It has numerous internal self-monitoring features, including:
- PWM controlled fan that turns on if internal temperatures exceed 30’ C (they never do, but…)
- digital temperature sensors to measure the temp of the power supply, MOSFETs, etc. If any temps exceed 50’C, the system will shut down for safety.
- an RS232 GPS unit to set time and location, updated every three hours (with daylight savings time correction). This saves me from ever having to set the clock — it will always be accurate. (I also don’t have to add buttons or a user-interface to set it)
- extensive USB serial port logging and status information
- the star post in the front, center, top of the clock changes based on system status - pulsing with the seconds, flashing yellow and blue for GPS updates, flashing red for a system fault, etc. It will also flash special colors on holidays (red / white / blue on the 4th of July, red / green on Xmas, etc)
- Computer voltage monitoring of the 24V solenoid power, lamp power, and 5V logic power.
- 3 digit LED voltage monitor which is selectable between the three voltage levels.
- Status LEDs for all output (each MOSFET, fan control, relays, etc)
- A current monitor for the overall system, which is tracked in real-time as solenoids fire. If a solenoid draws too much current, the system will go into fault shut-down mode.
- Master control relay which can shut down the 24V solenoid and lamp power for standby or fault conditions
- A speaker for simple status beeps and feedback tones
- Recording of the last three fault conditions to the EEPROM to be retrieved later via USB
- Saving of metrics data to EEPROM (number of times each solenoid fired, number of errors finding the zero position, average amount of time each solenoid was firing, current use of each solenoid, etc)
"CLASH OF THE TITANS"
Mondo Poster by Francesco Francavilla
My Artist Proofs have arrived! :)
And they look awesome! Check it out!
Will let everyone know when these will go for sale.
Poster by Francesco Francavilla. 24”x36” screen print. Hand numbered. Printed by D&L Screenprinting.
Needed some new hardware for this box, so we 3D printed some T-Rex feet (and added a raptor tooth & bone to the latch). I call it “Jurassic Park Rococo”. :)
Designed in Cinema4D, printed in PLA on what started life as a PrintrBot Jr. but is now, through many additions & modifications, our own Frankenstein creature.