Part I - Igniter & Battery
There are two electrical requirements for the shay:
The igniter and battery are discussed in this part and the lights will be covered in subsequent parts.
Unfortunately, no thought had been given to power generation or storage during the locomotive construction. There is no room for a small auto/motorcycle/lawn equipment type battery. The best alternative seems to be to stuff (hide) some D size cells between the tender frame members. That should be sufficient since there's no kids to leave the lights turned on. However, care must be taken to get maximum efficiency to extend battery life. To that end an electronically controlled 6 volt motorcycle coil was selected for the igniter and LED arrays for the lamps. Most the LEDs used in flashlights require ~3.9 volts each but can be arranged in parallel/series combinations of LEDs and resistors to form an array that will work at about any voltage greater than 3.9 volts. The motorcycle coil was the least expensive small coil I could find so that fixes the voltage at 6 volts or slightly less. Four regular 1.5 volt D cells gives 6 volts or four 1.2 volt NiCad or NiMH cells could be used to give 4.8 volts which would probably work or a fifth cell added to get 6 volts. I decided to start out with the four 1.5 volt cells and see how that worked out. If battery replacement becomes too expensive, I can switch to rechargeable batteries later.
Igniter: The igniter was viewed as the highest priority electrical item so it was constructed first. ( A large flashlight could be duct tapped to the front sill if needed before the headlamp is finished.) Dave Johnson provided much advice on the burner as well as the spark plug type and plug position as documented in the Burner Test & Modification Page . He also advised that most people use a Model T type coil that gives hundreds of sparks per second.
I'd heard references to Model T coils in a way that suggested that they were something special. Being an Electrical Engineer I attributed this to a myth or urban legend passed on by the uninformed. Dave said that Model T coils were available from Mac's Auto Parts. I checked out the coils at Mac's and found that four coils were used (one per cylinder) and the coils had contact points. Along the way I heard the term buzz coil applied to the Model T coil. At this point it sounded like they were indeed different; more than just a coil (my previous view was wrong --- not the first time). I then speculated the distributor distributed to the coil primary (6 volts) and that each coil was equipped with a vibrator (buzzer) to continuously pulse the coil whenever power was applied. A later conversation with my older brother confirmed the coils were self pulsing. (He also provided some tales about mischief with these coils in his youth.) The Model T coil sounded great but seemed to be larger than I wanted and I suspected that mechanical buzzer/pulser consumed significant power.
A subsequent Internet search found Jerry E Howell's website serving ignition needs of small model gasoline engines. Howell offers small coils and a kit to make an electronic circuit to pulse (buzz) one of his small coils or a 6 volt motorcycle coil. The buzzer kit and a few feet of small plug wire were purchased from Howell. A 6 volt motorcycle coil was purchased from the J C Whitney website. The size wasn't listed but it turned out to be smaller than a typical auto coil as hoped.
This shows the circuit hooked up on the desk for testing. The white wire is the high voltage lead from the coil. The alligator clip on the end of the green wire is touched to the clip on the black wire to turn on the coil. It worked!
Wiring Everything Together: The most important goal is to get everything wired together and to have the result function properly. Another goal is to be able to remove all the parts without cutting or unsoldering any wires. A third goal is to have the wiring not look like a rat's nest.
The above photo shows the top view of the circuitry. The tender front is to the right. This is all covered by the tender floor. The batter pack is connected to the switch panel via a 4 wire Molex type connector obtained from Radio Shack. Only three of the wire positions are used. The black wire is battery negative, the red wire is +6 volts and the blue wire is +4.5 volts (connected between the 3rd and 4th cell of the battery pack). On the switch panel side, the black wire is connected to a ground lug, the red wire to the front switch (igniter power) and the blue wire to the middle and rear switches (lamps).
The above photo shows the pulser circuit covered with electrical tape and all wires connected. The red wire near the left end of the coil is the coil + 6 volt lead that has a hooked lug on the coil end with the other end connected to the front toggle switch. The two screws securing the switch panel are removed to drop the switch panel. The pulser circuit will drop down with the switch panel.
Photo above shows the locomotive end of the cable with the cab floor removed. The white wire was cut off at the plug end and the stub spliced to the blue plug wire obtained from Jerry Howell with the pulser kit. That splice was covered with shrink tubing and a few layers of vinyl electrical tape. The four wires were then wrapped with the electrical tape to form a cable. The cable was taped to the right side water hose in several places. The cable was also taped to the copper tube from that right side hose under the cab floor. Note the the yellow wire was folded and taped to the water tube on the left side of the cab. This wire will be later connected to the headlamp and any cab lights. The brown wire is soldered to a ground lug that is screwed to the top of the truck bolster. The blue plug wire goes down to the spark plug. The green wire goes to the igniter switch beside the atomizer
Igniter Test: This part of the project has been done for a few weeks but I didn't want to put it on the website until the igniter was tested on a real live fire to make sure it actually worked. Today (4/15/04) was warm, sunny and beautiful in spite of the IRS so I sneaked off from lawn chores and fired up the Shay on the test stand. I couldn't get the burner to light initially with the igniter. That may have been because the fuel setting was incorrect. Once lit and adjusted properly I temporarily shut the atomizer valve --- flame went out --- then turned it back on --- then pressed the igniter switch ----- wow! ----it worked! After testing it a half dozen times I then played with burner adjustment. I found a bigger air hole is required at the rear of the pan --- the flame went out under full load unless the door was opened slightly. While fooling with this and other problems, the burner went out at least 25 times --- igniter relit it every time.
On a sadder note, the pretty blue high voltage wire near the spark plug is toast ---------- RIP. At times flames came out around the spark plug and went after that plug wire. The burner nozzle is horizontal and pointed right at the plug base. Maybe if I tilt it up a bit away from the plug hole, flames won't come out the plug hole (DAH).