Captain Crunch Geocache

Construction Guide

[   by LinuxOnTheBrain   ]



Introduction

    This is an electronic geocache with an audio triggered lock inspired by John Draper, a.k.a. 'Captain Crunch'. In the early 1970's John and his phone phreaker friends discovered that a toy whistle being included in boxes of Cap'n Crunch® cereal played a tone which could be used to control the (now retired) in-band signaling long distance telephone network. The phone companies used this tone to control long distance line connections, when played it would disconnect one end of the call leaving the remaining caller in Operator Mode. John and his friends quickly realized that Operator Mode = Free Phone Calls and the rest is telecom history.
    To open this geocache the user has to figure out the frequency of the toy whistle (variable frequency setting), then record a sample of that tone and bring it to the cache. At the cache the user must find the 'key' located on the cache, insert the key into the keyhole to power it up then play the pre-recorded tone to open the lock.
    Most of the materials used to build this unit were recycled from something else or I fashioned them myself from scraps. (To be earth friendly of course). I hope this inspires others to build electronic geocaches since disposable electronics are everywhere and can be easily reused. Feedback is appreciated. Thanks and enjoy!
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Acknowledgments

    To my beautiful wife Kim and loving daughter Carly who watched me tinker with this birdhouse for months and never thought I was crazy. Or at least never let on that they did. I love you both!
    To my brother Kevin who introduced me to geocaching. You rock!
    And of course to John Draper just for being himself.
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Table Of Contents

    Introduction
    Acknowledgments
    Preface
    Legal Notice
    Materials List
        Electronics
        All Other Materials
    The Electronics Pack
        Hacking The Voice Module
        Circuit Assembly
    The Casing
    The Center
    The Tall Side Back
    The Short Side Back
    The Short Side Front
    The Gearbox
    The Door
    The Short Side Lid
    The Tall Side Lid
    Assembly And Testing
    Painting
    Final Assembly
    Recommended Changes
   

Preface

    Please read this document completely before beginning the project. The builder needs to be aware of a number of things to avoid any problems and to take advantage of the recommended changes. It should be noted first that because most of the materials used were recycled the builder is encouraged to use what's available...be creative. Also important is that many of the measurements used in the design documents were taken indirectly (inferred) because they were taken after assembly so please double-check measurements and fittings during construction.
    Distributed with the construction guide pack are the original Xfig design documents. Xfig is a wonderful open-source (free) program similar to CAD and is available primarily for Linux. There is also a ported version for Windows. Xfig is an excellent tool for anybody interested in drafting project designs. If errors are found please let me know so the construction pack can be corrected.
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Legal Notice

(I don't know if I really need this but just in case here's one that works...)
This construction guide and its contents are distributed under the GPL license:
---------------------------------------------------
Captain Crunch Electronic Geocache
Copyright 2008 Tim Groninga

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
---------------------------------------------------
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Materials List

    Below are the materials that were used to construct this geocache. Replace with materials with you have where possible and/or appropriate.
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Electronics Materials
Quantity Item Cache Location Notes URL
1 Electret microphone Electronics pack A standard pc mic works nicely. Link
1 470 ohm 1/4W resistor Electronics pack Link
3 2.2k ohm 1/4W resistor Electronics pack Link
4 10k ohm 1/4W resistor Electronics pack Link
3 100k ohm 1/4W resistor Electronics pack Link
1 5k ohm linear taper potentiometer Electronics pack Link
3 3mm LED Electronics pack Link
3 BC-170C npn general purpose transistor Electronics pack A 2N2222 might also work. Link
1 330 micro-farad capacitor Electronics pack Link
4 10 micro-farad capacitor Electronics pack Link
1 4.7 micro-farad capacitor Electronics pack Link
1 2.2 micro-farad capacitor Electronics pack Link
2 0.1 micro-farad capacitor Electronics pack Link
1 0.022 micro-farad capacitor Electronics pack Link
1 5VDC reed relay Electronics pack Link
1 Low-noise 6VDC motor with gear Gearbox Radio Shack hobby motors are very noisy.
1 Momentary contact SPST push button switch Horizontal front switch Link
1 SPDT switch with rolling lever Vertical bottom switch Link
1 Momentary contact DPDT push button switch Door switch
1 Radio Shack voice record/playback module Electronics pack Link
1 LM567CM tone detector chip Electronics pack Free samples available. Link
1 4-AA battery carriage Electronics pack Link
4 AA alkaline batteries Electronics pack
1 Project Enclosure (3x2x1") Electronics pack Link
1 Grid-style PC board with solder ringed holes Electronics pack Link
1 22 AWG insulated solid-core hookup wire Electronics pack & general wiring Link
1 Crimp-on snap connectors Electronics pack & general wiring Link
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All Other Materials
Quantity Item Cache Location Notes
6.5 ft
3/4" thick, 4" wide pine
Casing, sides and bottom
2 ft. 3/4" thick, 8" wide pine
Lids
1 ft. 3/4" thick, 1x2 pine
Inside tall lid and short lid crossbar
1 Large hinge
Door
1 4" L-bracket Back of tall side
1 2" L-bracket Horizontal switch mount
2 Hex nuts
Bottom
1 Round magnet with 5mm-8mm center hole Bottom surrounding vertical switch
185mm 4mm steel tube Vertical and horizontal switches, door switch action Steel rod must move smoothly through tube.
250mm 3mm steel rod Door switch action, keyhole cover stops & key Steel rod must move smoothly through tube.
1 Gate latch Door
1 2-1/4" D-ring Tall back
2 Washers for d-ring Tall back
2 Hex nuts for d-ring Tall back
2 Couplers for d-ring Tall back
2 4" hex head bolts same dia. as d-ring Tall back
2 Combo coupler/washer nuts Tall back
2 Gears Gearbox Various sizes, see details pdf
? Lengths of steel Gearbox, rotary arm stop mount Various sizes, see details pdf
1 1-1/2" hinge Electronics cover panel
1 78mm x 85mm 3mm thick clear plexiglass Electronics cover panel
1 3/4" lock Electronics cover panel
1 50mm x 52 mm 3mm thick clear plexiglass Short side false hole cover
1 171mm long sliding door stop arm Door
1 14mm x 45mm 2mm thick brass piece Keyhole cover
1 2-1/4" long 1/4" hex head bolt Short lid
4 8# nails Short lid
100mm Reed steel Tall back rotary arm stop/door switch
70mm Spring coil Door pressure spring
2Large paper clipsLatch recoil spring
1Pen springLatch recoil spring
10 2" deck screws Casing and tall lid
7 1/2" wood screws Short front plexiglass plate
1 Plastic wood compound
1 Epoxy pack (15 min)
1 Wood glue
1 JB-weld pack
?MiscVarious screws, nuts & bits of steel
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The Electronics Pack

    The electronics pack consists of two parts, (1) the voice module and (2) the tone detector and control relay assembly. The voice module has to be modified (hacked) so it will operate when power is applied instead of by using the usual push-button. The tone detector and control relay assembly operate by taking in and amplifying an audio source then the audio is sent to the LM567 chip which compares the frequency of the input signal to that of its attached R/C resonant pair. If a match is found the output pin goes low and closes a relay to drive the motor. 
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Hacking The Voice Module
    The reason for hacking the Radio Shack voice module is to change the way the module works.
     Default Behavior:
     Hacked Behavior:
  1. To record to the voice module the recommended method is to create a synthesized voice sample from Cepstral. Then make an audio patch cord consisting of a 1/8" jack (or whatever your PC sound card has) on one end and alligator clips on the other. Connect the jack to the PC's speaker output and connect the clips to the speaker (microphone) terminals on the voice module. Press the recording button & start playback from the PC at the same time. Remember to disconnect the jack from the PC before testing the module recording playback!! (not disconnecting it causes an impedance imbalance and it sounds terrible). Some volume adjustment will probably be necessary to get the loudest clearest-sounding recording possible. To make things easier, do not proceed with the circuit modification below until the recording is satisfactory. Re-recording later is possible but a little more difficult because the recording button contacts have to shorted with a metal tool and held.
  2. After recording is complete the module can be hacked. Hacking the circuit board involves removing three capacitors then adding a 0.1 micro-farad capacitor and a short jumper wire. See reference pics. Remove power before working on the circuit board! Yellow circles are the capacitors to be removed, red indicates the capacitor and jumper wire to add. Also tear off the rubber playback button and snip off the recording control button, they won't be needed anymore. Tape the wire ends from the recording button to keep them from accidentally contacting.
  3. Twist a pair of wires together to make a five-inch long extension for the speaker/microphone. Un-solder the existing speaker wires and replace them with the twisted pair re-soldering both ends.
  4. Testing should be done when the modification is complete. Re-apply power to the module and check for the correct behavior. The recording should begin playing immediately and should loop continuously. If power is removed the recording should start again at the beginning when power is re-applied.
Reference Blueprints: none
Reference Pics:
   
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Circuit Assembly
    Assembling the circuit should begin on a bread board for testing purposes. The LM567 tone detector is sensitive to a few things that could cause it to trigger incorrectly. Things like a noisy power source or components, a noisy motor or nearby EMF sources. Testing all these components on a bread board before assembling the circuit will avoid problems later.
  1. Measure and cut the pre-soldered PCB board to fit into the top of the project enclosure. Make sure the four screw holes line up exactly. These holes may have to be drilled out slightly for a correct fit. Clip or sand one corner of the PCB board where the voice module speaker wire will come through later from below.
  2. Arrange the circuit components onto the PCB according to the circuit schematic. Leave open one or two row(s) of solder holes at both narrow ends of the board (depending on your arrangement). These will be used later for wiring connections. Preview steps 4-6 to make arrangements for these connections. It's recommended to arrange the battery connector and microphone connections on the side nearest the battery and all other LED, switch and motor connections on the opposite.
  3. Solder the components into place. 
  4. Use the solder holes at the ends to connect the battery pack coupler and microphone. Recommend drilling a pair of holes along the edge of the enclosure to fit a wire tie as a strain relief for the microphone and battery connector.
  5. Twist a pair of wires together to make a three-inch long extension for the potentiometer. Solder the wires to the potentiometer and then to the PCB board.
  6. Twist a pair of wires together to make two eight-inch long extensions for diode one and diode two. Solder the diodes to the wires and the wires to the board. Wrap small bits of electrical tape around the legs of the diodes to insulate them and prevent accidental contact.
  7. Twist a pair of wires together to make two six-inch long extensions for wiring harness connections for the vertical switch and horizontal switch. Strip the ends of the wires and crimp on terminal connectors then solder the wires to the PCB board.
  8. Twist a pair of wires together to make two twelve-inch long extensions for wiring harness connections for the door switch and motor. Strip the ends of the wires and crimp on terminal connectors then solder the wires to the PCB board.
  9. Flip the PCB board over & solder all circuit connections using very short pieces of connection wire.
  10. Twist a pair of wires together to make a six-inch long extension for a wiring harness connection for the motor itself. Strip the ends of the wires and crimp on terminal connectors then solder the wires to the motor.
  11. Create temporary terminal connections for the vertical and horizontal switches, strip and crimp on terminal connectors and solder wires to the switches. 
  12. Place the modified voice module into the bottom of the project enclosure securing it with double-sided tape or hot glue. Route the speaker/microphone wire out the corner of the enclosure where the PCB was sanded or cut. Solder the module's power connection into the circuit board using connection wire. 
  13. Place the PCB board back onto the project enclosure and drive in enclosure screws. 
  14. Test the unit. Create temporary connections to the switches and motor and connect power to the circuit. Be sure the switch sequence works right and that the correct normally-open/normally-closed poles were soldered to. At first the circuit isn't 'tuned' to any particular frequency, so play the frequency needed and with the proper switches closed, turn the potentiometer until diode two lights up. Diode one lights up when key switch one is closed, then when key switch two is closed the voice module plays and if the tone is played (after tuning) diode two should light up temporarily while diode three lights up when the motor is powered. 
** The Secret Hack
   
There's a secret hack to the audio lock that's been left intentionally. If you look closely at the schematic you see that key switch two prevents the motor from operating until the switch is closed. The reason switch two is there at all is because of an electrical property called 'relay bounce'. When a relay is initially charged it has the tendency to close immediately as power is applied then opens again moments later. The hack lies in switch two....if another length of wire is used to close this switch when key switch one is closed, relay bounce will occur causing the motor to trigger and open the lock, the audio tone detector circuit is bypassed entirely. This could be easily corrected with a digital logic chip but was left instead for true hackers (like John Draper) to find. If by chance a hacking geocacher is to discover this of course any report of the hack should be omitted or removed from logs.
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Reference Blueprints:
[Circuit_Schematic] [Electrical_Wiring_View]   

Reference Pics:
                   
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The Casing

    The basic casing of the cache consists of the bottom, tall left & short right pieces. The vertical switch, switch key & magnet will also be installed.
  1. Measure, cut and rough sand the bottom, tall left & short right pieces.
  2. Trim the corners of the bottom piece as shown.
  3. On the bottom piece upside, measure and drill the two holes for the horizontal switch fixture.
  4. On the bottom piece underside, measure and drill the two holes that hold the center piece. With a larger bit, drill again a couple of mm to counter-sink the screws. These will be filled in later to mask them.
  5. On the bottom piece underside, drill the holes for the vertical switch tube and false nut fixtures. Using a sharp tool or router remove a couple of mm to counter-sink the magnet that holds the key. 
  6. Cut and assemble the vertical switch key. Bend (or hammer flat) the end of the steel that goes into the nut slightly to prevent it from slipping out. Use jb-weld to fix the steel into the nut. Allow to dry.
  7. Use jb-weld to fix a casing screw into the nut that matches the key nut. Allow to dry.
  8. (See the switch tube installation and vertical switch fixture) Cut a length of steel tube for the vertical switch. Using a paper clip or heavy wire, wind the wire around the end of the tube positioning the lever switch directly above the hole. Use jb-weld to fix switch to the wire and the wire to the tube. Use the vertical switch key to test the switch action and adjust before the jb-weld sets. Allow to dry.
  9. Twist a pair of wires together to make a three-inch long extension for the vertical switch. Un-solder and remove the temporary wires. Strip the ends of the new wires and crimp on terminal connectors then solder the wires to the lever switch.
  10. Mount the vertical switch to the bottom piece using jb-weld making sure to place it as close to level with the bottom surface as possible. Make sure to position the switch so the solder contacts face the front of the cache. Allow to dry.
  11. Mount the magnet to the bottom piece using jb-weld making sure to place it as close to level with the surface as possible. Allow to dry.
  12. Apply plastic wood to the magnet/tube area to level the surface, allow to dry and sand smooth.
  13. On the tall left piece outside, measure and drill the two holes to attach to the bottom. With a larger bit, drill again a couple of mm to counter-sink the screws. These will be filled in later to mask them.
  14. On the tall left piece, measure and drill the two holes for the door pressure spring and door stop-arm.
  15. On the short right piece outside, measure and drill the two holes to attach to the bottom. With a larger bit, drill again a couple of mm to counter-sink the screws. These will be filled in later to mask them.
  16. Align the tall left piece, then the short right piece to drill pilot holes into the bottom piece. Make sure to retain a 5-mm overhang over the bottom.
  17. Apply wood glue to the tall left and short right pieces where they meet the bottom piece then drive in deck screws. Make sure the screws are countersunk a couple of mm for masking later.
Reference Blueprints:
[Bottom_Underside] [Bottom_Upside] [Tall_Left_Outside] [Tall_Left_Inside] [Short_Right_Outside] [Short_Right_Inside] [Misc_Parts_3]

Reference Pics:
          
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The Center

    The center piece allows access to the electronics side of the cache and holds the door switch, door switch tube and wiring harness hangers.
  1. Measure, cut and rough sand the center piece. 
  2. Measure & cut the center hole.
  3. On the center piece inside, measure & drill the holes for the harness wiring, & door switch push-rod tube.
  4. Measure & cut plexiglass for the cover door. 
  5. On the plexiglass, measure and drill holes for the lock and hinge. 
  6. Use short machine screws to attach the hinge to the plexiglass making sure to face the hinge pivot pin away from the center piece.
  7. Install the lock on the plexiglass.
  8. Measure and cut a small piece of plexiglass the size of one ear of the hinge. This will be a standoff between the hinge and the center piece so that the hinge is level with the door below. Mark and drill two holes in the plexiglass piece to fit the hinge.
  9. Use short wood screws to mount the door hinge to the center piece using the standoff.
  10. Test the operation of the lock. Some sanding may be required along the path the lock bar travels.
  11. Remove the cover door and hinge from the center piece and set it aside for now.
  12. Align the center piece with its position on the bottom piece and drill two pilot holes into the bottom of the center piece.
  13. Drive in deck screws to attach the center piece to the bottom piece. (no gluing at this point)
Reference Blueprints:
[Tall_Center_Outside] [Tall_Center_Inside] [Misc_Parts_1]

Reference Pics:
              
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The Tall Side Back

  1. Measure, cut and rough sand the tall back piece. 
  2. On the tall back outside, measure and drill the holes for the d-ring latch mount and birdhouse mount below.
  3. On the tall back outside, measure and drill the holes for the motor mounts and casing screws. With a larger bit, drill again a couple of mm to counter-sink the screws. These will be filled in later to mask them.
  4. On the tall back inside, measure and drill holes for the reed steel/rotor arm stop mount. 
  5. Install the d-ring latch bar, couplers, nuts, washers etc as shown. Attach the d-ring to the extension bolts using the couplers and tighten. The nuts on both sides of the tall back are used to adjust the position of the d-ring to fit the door latch later. Leave these nuts finger-tight for now and leave the extension bolts as they are, these will be cut off later.
  6. Align the tall back piece to the tall left and center pieces to drill pilot holes for the casing screws. Make sure to retain a 5-mm overhang over the bottom.
  7. Drive in casing screws. Make sure the screws are countersunk a couple of mm for masking later. (no gluing at this point)
Reference Blueprints:
[Tall_Back_Outside] [Tall_Back_Inside] [Tall_Back_Latch_Bar]

Reference Pics:
      
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The Short Side Back

  1. Measure, cut and rough sand the short back piece. 
  2. On the short back outside, measure and drill the holes for the short lid cross-bar and casing screws. With a larger bit, drill again a couple of mm to counter-sink the screws. These will be filled in later to mask them.
  3. Align the short back piece to the short left, tall back and bottom pieces to drill pilot holes for the casing screws. Make sure to retain a 5-mm overhang over the bottom.
  4. Drive in casing screws. Make sure the screws are countersunk a couple of mm for masking later. (no gluing at this point)
Reference Blueprints:
[Short_Back_Outside] [Short_Back_Inside]

Reference Pics:
     
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The Short Side Front

  1. Measure, cut and rough sand the short front piece. 
  2. On the short front outside, measure and drill the holes for the main opening, horizontal switch tube, keyhole cover & keyhole cover stops. Rough sand the main opening to round the edge.
  3. On the short front outside, measure and drill the holes for the short lid cross-bar and casing screws. With a larger bit, drill again a couple of mm to counter-sink the screws. These will be filled in later to mask them.
  4. On the short front inside, measure and drill the holes for the plexiglass hole cover.
  5. Measure and cut a length of steel tube for the horizontal switch. 
  6. Mount the horizontal switch tube in the short front piece using jb-weld making sure to place it as close to level with the outside surface as possible. Allow to dry.
  7. Apply plastic wood to the short front outside around the tube area to level the surface, allow to dry and sand smooth.
  8. Measure and cut the plexiglass for the short side hole cover. 
  9. Center the plexiglass cover over the main opening on the short front inside and mark the mounting holes then drill them.
  10. Measure and drill the 45-degree angle holes in the plexiglass cover.
  11. Use epoxy to attach two small circular standoffs to hold the LEDs.
  12. Set the plexiglass cover aside for now.
  13. Align the short back piece to the short left, tall back and bottom pieces to drill pilot holes for the casing screws. Make sure to retain a 5-mm overhang over the bottom.
  14. Drive in casing screws. Make sure the screws are countersunk a couple of mm for masking later. (no gluing at this point)
Reference Blueprints:
[Short_Front_Outside] [Short_Front_Inside] [Misc_Parts_2] [Misc_Parts_3]

Reference Pics:
         
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The Gearbox

    **Note: This is an 'adjustable' gearbox meaning that because the stepdown gear and motor are mounted on pivoting arms, slight variations in gear sizes are acceptable. It is, however, important that the position of the latch hammer in the birdhouse cavity remains the same. 
  1. Measure, cut and shape two pieces of steel for the gearbox frame. Drill holes in the legs for mounting to the tall back.
  2. Measure and cut two pieces of steel for the stepdown gear inner-frame. 
  3. Measure and cut a piece of steel for the latch hammer.
  4. Measure and cut two pieces of steel rod for the gear axles.
  5. Measure and drill holes for the axles in the gearbox frame and inner-frame. 
  6. Measure and drill a hole for the frame bolt (machine screw) in the gearbox frame and inner-frame.
  7. Assemble the gearbox frame, inner-frame, axles, gears and latch hammer. Use jb-weld to fix the axle-ends, gears and latch hammer into place. Allow to dry.
  8. Estimate, cut and shape a piece of steel for the motor mount bar.
  9. Measure and drill a hole in the motor mount bar to attach it to the side of the gearbox.
  10. Using plastic wire ties, strap the motor onto the end of the motor mount bar.
  11. Attach the motor mount bar to the gearbox using an additional machine screw nut.
  12. Adjust the whole gearbox & motor assembly to get all the parts 'square' and the gears in proper contact with each other. Then tighten the nuts down hard.
  13. Apply jb-weld around the gearbox frame nuts and joints except for the nut over the motor mount bar. Allow to dry.
  14. Use machine screws to mount the gearbox to the tall back piece and tighten. Machine screws will be trimmed off later before masking the nuts.
Reference Blueprints:
[Gear_Box]

Reference Pics:
                   
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The Door

  1. Measure, cut and rough sand the door piece. 
  2. On the door piece outside, measure and drill the hole for the main opening. Rough sand the main opening to round the edge.
  3. On the door piece inside, measure and drill the holes for the door stop arm.
  4. Measure and cut the end of one ear of the large hinge.
  5. Position the hinge on the door piece outside fitting it into the notch at the bottom and mark the holes.
  6. On the door piece outside, drill the holes for the hinge.
  7. On the latch, drill a hole in the side of the latch and in the front & side of the latch strike plate.
  8. Measure, cut, shape and drill a piece of steel for the new strike plate.
  9. Measure and cut two pieces of steel rod for the upper and lower recoil spring mounts.
  10. Use jb-weld to attach the lower mount, add a nut or washer to the end as a stopper. Allow to dry.
  11. Use jb-weld to attach the new strike plate and upper recoil spring mount to the latch strike plate. Make sure the compound goes through the latch strike plate and the new strike plate together to act like a rivet. Allow to dry and sand smooth.
  12. Shape a couple of large paper clips to form the two halves of the recoil spring guides.
  13. With the latch in the forward (closed) position, place the two recoil spring guides over the upper and lower mounts. Feed the pen spring onto both.
  14. Slide the spring to one end and bend the legs on the exposed spring guide ends. Then compress the spring fully the other direction and bend the legs on the other spring guide ends. Release the spring. 
  15. Test the recoil spring action.
  16. Pull the latch back to the full recoil spring extent, check to make sure the latch travels far enough to release the latch bar. On the top of the latch, mark the position of the strike plate arm.
  17. Measure and cut a piece of steel to act as a brake bar across the top of the latch. This piece prevents the latch arm from being over-extended and bending the recoil spring guides. Use jb-weld to attach the brake bar to the top of the latch at the position previously marked. Allow to dry.
  18. On the door piece inside, center & square the aluminum cover from the electronics box over the main opening hole. Mark and drill the mounting holes then drive in screws to attach the cover to the door inside.
  19. On the door piece inside, center & square the latch over the aluminum cover. Mark and drill the mounting holes then drive in screws to attach the latch to the cover and door piece.
  20. Measure and cut a piece of steel to place between the two screws where the door pressure spring contacts. Use jb-weld to attach the steel piece to the aluminum. Allow to dry.
  21. Measure and cut a piece of metal coil for the door pressure spring. Bend back the bottom 3-mm 90-degrees and drive in a screw to attach it to the tall left side inside.
  22. On the door piece outside, drive in screws to attach the hinge.
  23. Align the door piece to the tall left, bottom and center pieces. The hinge should be square to the bottom and the 5-mm overhang should be retained. To allow for paint thickness, leave a small (1mm?) gap between the door and the tall left, bottom and center pieces. Mark and drill the hinge mounting holes into the bottom piece then drive in screws to attach the door to the casing.
  24. Install the door stop-arm, drive in screws to attach it to the door piece and tall left piece.
  25. Test the operation of the door hinge and latch. Check that the latch meets the d-ring at the correct level and that when the latch closes the door is fully closed. 
  26. Adjust the nuts holding the d-ring for a correct fit. Then tighten the d-ring mounting nuts fully.
  27. Estimate and drill an angled hole through the back for the emergency release. The hole should be aimed at the strike plate of the latch. Test with a length of coat hanger wire. If not exact, overdrill the hole and insert the hanger wire then press plastic wood into both sides of the hole while aiming the wire at the strike plate. Allow to dry then remove the wire and sand smooth.
Reference Blueprints:
[Tall_Front_Outside] [Tall_Front_Inside] [Door_Latch] [Misc_Parts_2] [Misc_Parts_3]

Reference Pics:
                       
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The Short Side Lid

  1. Measure, cut and rough sand the short lid piece. 
  2. On the short lid piece outside, measure and drill the holes for the four guide nails and the center bolt. With larger bits, drill again a couple of mm to counter-sink the screws and the bolt. These will be filled in later to mask them.
  3. Hold the short side lid in place and align with the center, short front & back sides. Lid should be flush with the back. Mark then drill the holes in the short front and short back sides for the guide nails.
  4. Cut the four 8# nails to length. Using jb-weld, coat the inside of the nail guide holes lightly then push the guide nails through. Nails should be countersunk a couple of mm. Apply another 2-mm of jb-weld to cover the nail heads. Wipe off excess and allow to dry.
  5. Measure, cut and rough sand the short lid crossbar. 
  6. Using the short side false hole cover as a guide, position the short lid crossbar and drill pilot holes into both sides from the short front and short back. 
  7. Drive in screws to attach the short lid crossbar to the short front and short back.
  8. Put the short lid into place, drop the guide nails into the holes in the short front and short back and press fully into place.
  9. Mark and drill the hole for the short lid center bolt through the short lid crossbar.
  10. Lift the short lid off. Remove the short lid crossbar then glue a flat washer to the bottom side. 
  11. Using jb-weld, coat the inside of the center bolt hole lightly then push the center bolt through. Bolt should be countersunk a couple of mm. Apply another 2-mm of jb-weld to cover the bolt head. Wipe off excess and allow to dry.
  12. Rough sand then fill the guide nail and center bolt holes with plastic wood, allow to dry and sand smooth.
Reference Blueprints:
[Short_Lid_Outside] [Short_Lid_Inside] [Misc_Parts_1]

Reference Pics:
           
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The Tall Side Lid

  1. Measure, cut and rough sand the tall lid left and right side pieces.
  2. On the tall right lid outside, measure and drill the holes for the three casing screws. With larger bits, drill again a couple of mm to counter-sink the screws. These will be filled in later to mask them.
  3. On the tall left and right lid outsides, measure and drill the holes for the two small door jams. With larger bits, drill again a couple of mm to counter-sink the screws. These will be filled in later to mask them.
  4. On the tall left and right lid outsides, measure and drill the 45-degree angle holes for the vertical casing screws. With larger bits, drill again a couple of mm to counter-sink the screws. These will be filled in later to mask them.
  5. Align the tall right lid with the tall left lid, mark and drill the pilot holes for the casing screws into the left lid.
  6. Apply glue to both edges and drive in deck screws to attach the tall right lid to the left lid. Make sure the screws are countersunk a couple of mm for masking later.
  7. Measure, cut and rough sand the left and right door jams.
  8. Using a router or a sharp tool, remove the area indicated on the right door jam. This is to accommodate the larger latch strike plate.
  9. Align the left door jam under the tall left lid piece, mark and drill a pilot hole in the left door jam. Then align the right door jam under the tall right lid piece, mark and drill a pilot hole in the right door jam.
  10. Apply glue to both edges and drive in screws to attach the left door jam to the tall left lid, then the right door jam to the tall right lid.
  11. With the door closed and latched, place the tall side lid on the birdhouse and align with all sides, flush to the back. Mark and drill the vertical pilot holes for the casing screws into the tall left and center pieces.
  12. Fill the tall lid casing screw and door jam holes with plastic wood, allow to dry and sand smooth. Do not fill the vertical casing screw holes yet.
Reference Blueprints:
[Tall_Lid_Outside] [Tall_Lid_Inside] [Tall_Lid_Extra]

Reference Pics:
       
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Assembly and Testing

    To test the operation of the cache all parts except the plexiglass pieces need to be installed. This allows testing of the electronics pack, the key switches, the gearbox and the door latch operation.
  1. Measure and cut a length of reed steel for the rotor stop arm.
  2. Measure, cut and drill two lengths of steel for the rotor stop arm mount.
  3. Place the reed steel between the mounts and drive in screws to attach the mounts to the tall back piece.
  4. Adjust the reed steel so that the rotor strikes the reed steel at the center of the rounded edge. The reed steel should not slip forward or backward when struck.
  5. Measure and cut a length of steel tube and a length of steel rod for the door switch push-rod. (The push-rod has two functions, to press the door switch and depress the reed steel when the door is closed.) 
  6. Feed the rod through the steel tube and bend to shape.
  7. Drill mounting hole and drive in eyehole screw to hold the lower arm of the steel push-rod.
  8. Fit the steel rod through the eyehole screw and drive in three screws to mount the steel tube/rod assembly to the center piece.
  9. Measure, cut and drill a length of steel for the door switch mount. This needs a long hole for adjustment of the door switch.
  10. Use jb-weld to attach the door switch to the door switch mount.
  11. Twist a pair of wires together to make a three-inch long extension for the door switch. Un-solder and remove the temporary wires. Strip the ends of the new wires and crimp on terminal connectors then solder the wires to the door switch.
  12. Place the door switch and mount on the center piece aligning the switch surface with the tip of the steel push-rod. Mark mounting holes.
  13. Drill mounting holes and drive in screws to mount the door switch.
  14. Twist a pair of wires together to make two eight-inch lengths. Then strip and crimp on terminal connectors to use as a temporary wiring harness.
  15. Twist a pair of wires together to make a three-inch long extension for the horizontal key switch. Un-solder and remove the temporary wires. Strip the ends of the new wires and crimp on terminal connectors then solder the wires to the horizontal key switch.
  16. Install the horizontal switch into the two inch l-bracket then drive in screws to attach to the bracket to the bottom of the short side. Slide the key through the horizontal switch tube to check position.
  17. Place the electronics pack and battery pack in the short side. Connect the electronics to the battery pack and the vertical and horizontal switches. 
  18. Feed the wires through the center piece and connect them to the electronics pack one one side, and the motor and door switch on the other.
  19. Drape the LED lights and microphone out the short side front opening.
  20. Insert the key into the vertical switch tube.
  21. Place the short lid crossbar and drive in screws to attach it to the short front and short back pieces.
  22. Place the short lid and tap it into position then reach through the center piece and finger-tighten the fastening nut.
  23. Place the tall side lid and drive in deck screws.
  24. Close and latch the door.
  25. Test the operation series: Remove the key & look for diode one to light. Then insert the key into the horizontal keyhole & listen for the voice module playback. Play the tone & watch for diode two to light briefly and the motor should trigger opening the door. 
  26. Make any adjustments now before painting!
Reference Blueprints:
[Electrical_Wiring_View] [Tall_Back_Inside] [Tall_Center_Inside] [Misc_Parts_1] [Misc_Parts_3]

Reference Pics:
               
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Painting

    After removing some parts and gluing some others, there are six main pieces of the cache to be painted: the casing, door, tall lid, short lid, center piece & plexiglass hole cover. There will also be some touch-up painting to do later after final assembly.
  1. Using a hack saw or dremel tool, cut and grind smooth the bolts for the gearbox mount and latch bar.
  2. Fill the area around the latch bar nuts on the tall back outside with plastic wood, allow to dry and sand smooth.
  3. Remove the following parts: key, tall lid, short lid, short lid crossbar, electronics pack, battery pack, horizontal switch & mount, temporary wiring harness, door switch tube and eyehole screw, door switch, door pressure spring, door stop arm, rotor stop arm & mount and the gearbox.
  4. Remove the hinge from the casing and from the door.
  5. Remove the center piece from the casing.
  6. Remove the following parts then apply wood glue to the opposing edges and reattach: tall back, short back and short front. (Apply a small amount of wood glue or plastic wood between the tall back and short back to close the seam).
  7. Fill the populated casing screw holes from the previous step with plastic wood, allow to dry and sand smooth.
  8. Use painters masking tape to cover the following parts: door latch, latch bar, vertical switch and tube at both ends, horizontal switch tube, short lid guide nails & fastening bolt.
  9. On the plexiglass hole cover, cut two small circles of masking tape to cover the outside of where the LEDs are placed. Cut two more pieces of masking tape to cover the ends of the circular standoffs that hold the LEDs
  10. Apply two coats of primer (lightly sanding between coats) then three coats of paint (color of choice & lightly sanding between coats) to the following parts: the casing, door, tall lid, short lid & center piece.
  11. Use a small brush to apply an additional (extra smooth) layer of paint around the area where the short lid meets the cache sides and center. (This makes removal of the lid easier when using silicone to weatherproof the seam).
  12. Apply two coats of primer then three coats of black paint (lightly sanding between coats of each) to the plexiglass hole cover.
  13. Use a small brush to apply three coats of black paint to the bottom of the false hole on the door.
Reference Blueprints: none

Reference Pics: none
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Final Assembly

  1. Remove masking tape from the plexiglass hole cover, short lid guide nails & fastening bolt, horizontal switch tube, vertical switch and tube at both ends, latch bar and door latch.
  2. Reattach the horizontal switch & mount.
  3. Reattach the door switch tube & eyehole screw and door switch to the center piece.
  4. Twist a pair of wires together to make two eight-inch long extensions for the wiring harness. Feed the wires through the hole in the center piece then strip and crimp on terminal connectors.
  5. Place the plexiglass false hole cover in the short front and drive in screws to attach.
  6. Place the plexiglass door cover on the center piece and drive in screws to attach.
  7. Reattach the center piece to the casing, drive in deck screws on the bottom and casing screws on the tall back.
  8. Reattach the hinge to the door and the casing.
  9. Reattach the door pressure spring, door stop arm and the gearbox.
  10. Reattach the rotor stop arm & mount making sure to place the reed steel behind the end of the door switch push rod.
  11. Replace the electronics and battery pack in the short side. Connect the battery pack.
  12. Plug in terminal connections to the electronics pack: vertical switch, horizontal switch, wiring harness (both sides) which includes the motor and door switch. Drive in small eyehole screws for wiring support where needed.
  13. Shape LED wires to position both of the LEDs in the circular standoffs. Touch a small drop of superglue to hold each LED in position.
  14. Estimate, cut and shape a short length of steel rod to support the microphone. Position the microphone then mark & drill a hole for the mount. Fit the new support on the microphone and insert into mounting hole. 
  15. Using a few short lengths of wire as wire ties, arrange and wrap wires where appropriate to make them more manageable.
  16. Position the short lid crossbar and drive in deck screws to attach it to the short front and short back pieces.
  17. Position the short lid and tap into place. Then reach in through the center piece and twist on the locking nut.
  18. Position the tall lid and drive in deck screws to attach it to the tall left and center pieces.
  19. Replace the key into the vertical switch.
  20. Drive the screw with the matched key nut into the bottom.
  21. Measure, cut and glue in keyhole stop pegs.
  22. Drive in casing screw to attach the keyhole swing cover.
  23. Close the door and COMPLETELY TEST THE CACHE!
  24. When everything checks out, fill the remaining exposed casing screws with plastic wood, allow to dry and sand smooth.
  25. Using a brush, apply coats of primer and paint to the plastic wood spots using the routine steps.
  26. Place the four-inch l-bracket on the back and drive in screws to attach the bracket to the bottom.
  27. If placing the cache outdoors, remove the short lid and apply a bead of silicone around the short lid contact surface.
  28. Optionally apply jb-weld to screw heads of the outer and inner hinges to discourage removing them.
Reference Blueprints: none

Reference Pics:
       
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Recommended Changes

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Last updated 7/16/08