Sunday, November 23, 2008 Bob the Grave Popper

A quick video of Bob in action. A new wiper motor prop for this year.

Monday, November 17, 2008 The Sinking Springs Cemetery

The Sinking Springs Cemetery in Abingdon Virginia has some vintage stones, with the oldest burial date being July 1776.

It is also home to the coolest earthen tomb that I have ever seen...










...and my favorite cemetery sign of all time.

This Should Explain Alot

My Dad raised birds in retirement, and that is how concerned neighbors came to bring him a large egg that mischievous boys had removed from a nest. It was 1996.

He was excited when it showed signs of life, anxious to find out what kind of bird he was incubating.

When it hatched, a turkey vulture chick popped out. Dad reared the little vulture with care in hopes of releasing him when he was grown. When that day came, the turkey vulture (now known as “Ichabod”) preferred to stay. After his “release” he continued to follow Dad around the yard and hang out around the house.

Knowing that Ichabod could not survive on his own, Dad contacted a local raptor center and they accepted Ichabod, where he is still active in school visits as part of their education program.

When Dad passed away in 2002, Mom had his gravestone engraved with his favorite photo – one of him holding Ichabod.

On a recent visit to the local school, Ichabod’s handler asked if she could visit Dad’s grave. The photo below is from that visit.

Monday, November 10, 2008 Halloween 2008

This year we took it easy and just set a few props at our friend's house. Sweet little Jewels is high tailing it away from Oliver.

This is Bob, a simple motorized grave popper we made this year from instructions on Haunt Forum.

Natalia returns for her third season as the ever popular flying crank ghost.

Lydia was excited to go trick-or-treating, but paused long enough for us to snap this shot with Oliver.

Saturday, November 8, 2008 Corpse Celebration

What is it about human remains that is so interesting? Recent remains do not hold my interest, but ancient remains can be captivating. These are a few catacomb images that I thought were compelling.

Failed Casting

We had a failure while casting some skulls in two part foam. The failure will not survive, but I thought it was cool.

Thursday, October 30, 2008 Ohio State Reformatory

We visited the Ohio State Reformatory site in September 2008. The structure and tour were absolutely fascinating.

The Casket Cleaned Up

The amount of rodent waste accumulated inside the casket eliminated any potential to keep it in original condition. A bio-hazard style cleaning was necessary.

The clean up brought out the beauty of the box. The box and lid are built of 3/4" pine boards and would accommodate a person up to a height of 5' 11". That would probably cover most folks in 1920s.

The box tapers from bottom to top in all dimensions. Exterior dimensions at the base are 73-1/2" length by 19" width. At the top the box measures 77" length by 22-1/8" width. The sides and ends are solid boards of 11-1/4" height. Two boards of 9-1/2" width compose the bottom of the box.

The lid is constructed of two 11" wide boards overlapped by a 9-1/2" board. Overall dimensions of the lid are 77-1/2" length by 22-3/4" width.

The lid is secured to the box with four rather decorative thumb screws. This was a cool and surprising detail.

The Casket

An account of the acquisition of a vintage casket.

"M. V. Wright Funeral Director" operated from a small carriage house in Troy, Virginia in the 1920s.

A good friend preparing the building for demolition found a few artifacts.

This sign hung in front of the carriage house.




The nameplates are all that remain from the old horse-drawn hearse.

And in the rafters was a pine casket. Apparently a deluxe model with a black fabric exterior finish and fully upholstered interior (with straw padding). This casket is mentioned in a 1966 article about Mr. Wright, copied below.

Windshield Wiper Motor

Let's take a moment and reflect on the unappreciated windshield wiper motor. Great torque, dual windings, quiet operation for under $20 - this baby is made for Halloween. The wiper motor as removed from the car has a 'park' position that gives you a clunk every revolution. It is simple to open the case of the gear assembly and take out the cam that caused the thump. I mounted mine to a 3/4" plywood base that has proven handy for installing the motor to a variety of props. It also helps electrically isolate the motor case (DC ground) from any other AC prop accessories, such as the PC power supply below.

This is the schematic for the entire wiper/washer circuit in a GM vehicle. The wiper/washer switch is not part of the wiper motor assembly but is included because it identifies the function of timer and cycle switches built into the motor assembly. The only connections that I have used for props are the Purple (+12 volt for high speed), Yellow (+12 volt for low speed) and Black (12 volt chassis ground). These wires all come from a three-pin connector on the motor itself. Note that you would connect either the Purple wire or the Yellow wire to +12 volt, depending on your desired speed, but never both.

Scary Terry - Wiper Motor

Howstuffworks - Wipers

PC Power Supply

The great companion to the wiper motor - an old PC power supply. This one provides three output voltages rated at 10 amp each - 12v (yellow wires), 5v (red wires), and 3.3v (orange wires). The great thing is that the three output voltages and the wiper motor 's dual windings in combination produce quite a range of RPMs. For instance, the 5 volt output connected to the low RPM motor wire produced the perfect speed for the Flying Crank Ghost.

I mounted a nylon terminal strip to the case of the power supply and terminated the output wires there to make it easier to use in a variety of props.

Relays

Here is a simple cycle control circuit for a two-stage prop. Requires two 12 volt relays and two momentary switches (with "normally closed" terminals).

Switch 1 is mounted to be actuated when the prop is in the "at rest" position. Switch 2 is mounted to be actuated when the prop arrives at the "full scare" position. A negative trigger (either from you or a motion sensor, etc.) causes Relay 1 to 'latch', and in turn activates the Relay 2 to provide 12 volt power to the wiper motor. When the prop pops up or does whatever its thing is and hits Switch 2, the latched relay deactivates and stops the motor. The prop is then reset by a second negative trigger (either from you or a timer) which provides power to the motor to return the prop to its ready position.

If your prop requires just one cycle - meaning it triggers, does its thing and returns to its original position in one continuous motion, only one momentary switch would be needed.

This configuration worked quite well and was cheap to make. NOTE: the 12-volt power feed needs to be fused for safety.

This control circuit was posted on the HauntForum by TommaHawk. It offers all of the functionality of the first circuit and adds the ability to reverse the polarity (and therefore direction) of the motor.

This is an old hack that I did to a cheap RC car in order to use the radio control circuit to control a larger prop powered by two wiper motors and a lawn tractor battery. It actually worked well, given the limited range of the toy. I ended up doubling the length of the receiving antenna and that helped. This completely mobile style of prop is fun, but really offers potential for injury.

You Gotta Love Relays!

A relay is an electromechanical device that uses an electromagnetic coil (electro) to move switch contacts (mechanical). The coil can be energized with a small amount of current, while the switch contacts can be used for a number of applications, including switching, isolating, or polarity reversal of high current circuits.

Power transistors have gained popularity for high current switching, but lack the flexibility of the “make and break” functions of the relay.

A typical 12-volt relay requires a coil current of .150 Amps to energize. The relay contacts can switch currents up to 30 Amps, creating a power gain as high as 200 to 1.

The classic automotive relay is the Bosch E5000. There are many variations of this design, but thankfully most manufacturers follow a standard nomenclature.

The Coil
Terminals 85 and 86 form the coil contacts. As current is passed through the coil, a magnetic field is produced, which actuates the switch contacts, causing terminals 30 and 87 to close. In order to pass current through the coil, 12 Volts must be applied to one side of the coil while Ground is present on the other. Most relay manufacturers recommend that terminal 85 should be connected to Ground, and 86 should receive 12V, but in fact the coil is non-polarized and either connection works. The only time polarity must be observed is when a “quenching diode” has been installed across the coil terminals.

The Contacts
Terminals 30, 87A and 87 form the contacts. When the relay is at rest, terminals 30 (Common) and 87A (Normally Closed) are connected. After the relay coil is energized, terminal 30 breaks its connection to 87A, and makes a connection to terminal 87 (Normally Open). Knowing this action of the contacts allows you to apply the relay in various configurations to achieve the desired results.

Common Types of Automotive Relays are identified by poles (the number of isolated common contacts) and throws (the number of isolated connections that the wiper arm contacts). The classic relay is a single-pole (one common contact) double-throw (one normally-open and one normally-closed contact), or SPDT.


Positive Trigger to a Negative Output




Converting a Negative Trigger to a Positive Output




Using Relays To Reverse Polarity

20 Second Recorder

We needed an audio source that was recordable, repeatable and could be remotely triggered. Our first thought of hacking a CD or MP3 player seemed impractical at the time based on cost.

Radio Shack's 20-Second Recording Module proved an affordable solution at $11. The unit is a small circuit board that comes with an attached 16-ohm speaker (for recording and playback), tiny circuit board mounted record switch and 9-volt battery clip.

The idea is to push and hold the record button (LED confirms status), speak loudly into the speaker then release record button. One push of the play button on the main board provides tinny playback.

To make this low-fi device useful, we need to:

• tap the play button with two wires to trigger play

• replace the speaker with a mini jack to connect to a PC (recording) and an a mp (playback)

• attach power wires and wean this thing off 9-volt batteries

• fit the whole shebang in some kind of protective box.
  

A little experimenting proved that the recorder operated fine from 5-volts. We will be using a PC power supply to power a 12-volt prop, so we already had 5-volts with nothing to do. Cutting off the 9-volt battery clip and splicing a length of wire on each lead takes care of power. The wire attached for power and ground will be about 18" long and should provide for many splices into different applications.

The play button can be visually traced. One pole connects to ground near the power connection, and the other pole connects to the switch side of resistor R3. So, a length of small gauge wire soldered to each location provide remote trigger inputs.

The mini jack connector that I had was salvaged from a PC. It was a stereo-mini and although this is a very mono device I soldered both positive leads from the stereo-mini to the positive speaker output of the board. The braided shield from the stereo-mini jack was soldered to the negative speaker output of the board. The connection nearest the "SPK" silkscreen was identified as positive based on a "+" marking on the speaker terminal.

An old Altoids tin seemed an appropriate enclosure. Three holes drilled in the sides and she was good to go. The stereo mini jack was threaded and mounted with a panel nut. I cut a grommet in half to protect the power and trigger wires where they passed through. The circuit board is secured by four big globs of hot melt glue. These adhere it in place and stand it off the tin a bit to eliminate any chance for shorts. Hot melt to each wire pass through provided a bit of stress relief and insulation.




At the last minute we extended the record switch wires so that it could be mounted to the lid. This keeps it protected through normal use (an accidental push erases your audio!), but still handy for recording.

The few modifications are simple and do improve functionality. Mounting it in a tin seemed to reduce the unit's susceptibility to interference. This had caused some erratic triggering from nearby devices, most notably a fog machine.

Practical application finds our little Altoids box hooked up to a PC power supply for 5-VDC, with the trigger wires extended to a relay mounted inside an animated prop, and its stereo mini output connected to a car amplifier driving two 6X9 speakers. What we lack in audio quality can be made up in volume.

In the end the results are satisfactory. Experimenting with PC level setting when recording the audio produced ample output volume. Sound quality is poor - think telephone - so selecting a simple audio track with limited or compressed frequency range gives better results. It is useful enough that we made two.