Conversion Goals

This is one of the two engines I plan to make available to visiting grandkids and others who may not show the respect more expensive equipment requires.  The switcher I'm modeling is the most widely produced Aristocraft steam locomotive.  In starter kits it is sold without tender and a small coal bunker attached to the rear.  In other settings it is sold with a slope back tender.  My version was in a starter kit.  But I scored a slope back tender on eBay a while back so at some point I may want to use the tender as a battery car.  For now, power will be provided by my first battery car, an Aristo Classic box car discussed in a separate thread.



Because of its intended use, my objective is to do this conversion on the cheap.  In addition to a motor powering this 0-4-0's movement down the track, it has a front headlight, a fire box light, and a smoke unit.  I intend to maintain operation of the lights and smoke unit.  I want to credit George Shreyer's tip page on the Aristo 0-4-0 for information on how to disassemble this engine.  This page doesn't cover battery conversion, but it has many other useful tips for this engine.

www.girr.org/girr/tips/tips2/040_tips.html

Conversion

The first step was to separate the boiler and cab from the rest of the engine.



This can be accomplished by removing three screws.  The first two attach the cab to the engine and are located a the far top and bottom edge of the engine between the rear drivers and what looks like cylinders directly below the cab.  Remove these two screws and the cab can be removed from the engine.  Be careful not to bend the pipes (wires) that run from the boiler on top that poke through the front of the cab.  They are visible in the previous engine profile photo.  The third screw is deep in the recess just in front of the front drivers.  You can see a white wire in this area in the above photo.  Once the third screw is removed you can separate the boiler from the lower part of the engine.  You'll need to pull up on the rear of the boiler as a tab the width of the engine fits rather tightly into a slot at the back of the engine.

  

This photo shows the disassembled engine.  You can see the slot in the base about 1/3 of the way from the back of the engine.  A corresponding tab at the back of the boiler fits into this slot.  The wires coming from the front of the engine feed the headlight and the smoke unit.  The smoke box cover pops off, but be careful not to pull the headlight wires loose when removing.



This is a closeup of the wires at the back of the engine.  At the bottom of the photo are five wires soldered to a connector that is screwed into the bottom of the engine.  The three large red wires go through a hole in the floor to the driver area on the lower side of the engine.  The small black wire feeds the smoke box light.  A large black wire runs under the weight to a circuit board that feeds the headlight and smoke device.

At the top of the photo is another group of five wires soldered to another connector that is screwed into the bottom of the engine.  The three large red black go through a hole in the floor to the driver area on the lower side of the engine.  The small red wire feeds the smoke box light.  A large white wire runs under the weight to a circuit board that feeds the headlight and smoke device.

For a battery conversion, the three lower large red wires and the three upper red wires are our primary focus.  Two of the three red and black wires provide electricity to this area through pickups attached to the drivers.  The third red and black wire routes the electricity from the pickups back down to the motor located below the floor.  We are going to want to disconnect the driver pickup wires, but leave the wires to the motor intact.  Unfortunately from this view there is no way to know which is which.



This view shows the 0-4-0's drivers.  Three rods are connected by the lower screw to the left (rear) driver.  The innermost main rod connects the front and rear drivers and parallel to the ground in this photo.  The middle piston rod runs from the rear driver to the piston.  The outside rod serves the Walschaerts valve gear.  In order to remove the rear driver, we'll need to remove the lower screw and slide all three rods off the bearing protruding from the driver.  This is the only portion of the valve gear that will need to be disassembled.  Repeat this step on the other side of the engine.



In this photo the rods have been removed from the rear driver bearing and are hanging loose.  The next step will be to remove the lower motor case.  It is held in place by the four screws at the edge of the case.



In this photo the motor is exposed.  The rear driver has been lifted out of its mounting slots and is laying a little further back than before it was lifted.  Before lifting out the rear driver, it would be a good idea to mark the drivers at the point where they would contact the track (facing up at you in this photo).  Knowing where these drivers were rotated before removal will eliminate some fiddling when it comes time to reassemble.

You can see two rectangular brass tabs that are floating just on the inside of the driver wheels.  There is a red wire attached to the lower tab and a black wire to the upper tab.  These are the electrical pickups to pick up track voltage from the rear drivers.  If you clip those leads close to the brass tabs, you will be able to remove the rear drivers and set them aside.  You will also have located and disconnected one pair of pickups.

The red and black wires running parallel to the motor cylinder are the wires feeding power from the front driver pickups.  You can clip these close to the front drivers.



In this photo, all four track pickup leads have been clipped and the rear drivers removed.  After this step, I turned the engine on its side, pushed on the clipped wires from the bottom and fished them through to the top using a pair of needle nose pliers.



This photo shows the motor area after the track pickups have been fished through the top.  The only two remaining red and black wires are those soldered to the motor.  It's time to close up the bottom end,



In this photo the rear drivers are back on the engine.  The alignment of the bevel gear on the driver shaft and the worm gear coming out of the motor is crucial if the main rods are going to line up.  If you marked the bottom of the drivers when suggested earlier, this step should be easy.  Align the brass pickups with the long side vertically and the snipped wire ends pointing toward the front of the engine.  Slide the pickups into their slots part way then rotate the rear drivers until your marks are pointing straight up.  Push the pickups in the rest of the way until the bevel gear mates with the worm gear.  Then slide the main rods over the bearings to make sure your alignment is correct.

Forgot to mark your drivers like I did?  It will take a bit more fiddling until you are able to slide the main rods over the bearings.  Then slide the piston rods over the bearings, followed by the rods serving the Walschaerts gears.  Replace the screws and your engine should look like the above photo.

 

Reinstall the bottom case cover using the four screws removed earlier and the bottom end of the engine is finished.  Turn it back on its wheels.



You should be greeted by two red wires and two black wires that are attached on one end to the solder joint and attached to noting on the other end.  All the rest of the engine wiring is intact and should be unaffected by this modification.  Once we've supplied battery power, lighting should still work as should the smoke unit.

I stopped at this point as I haven't yet selected the connectors I will use to attach this engine to the battery car.  But only two wires will be needed.  I'll attach one pair of my former track leads to the wire connecting with the battery car.  The connection will be made in this area.  The other pickup will probably be clipped at the solder joints.  I'll finish this project as soon as the connector issue is sorted out.  But I'm nearly done, with only a bit of soldering, wire routing, and a bit of reassembly to finish.

Cost?  To this point, this engine conversion has cost nothing!  Now that's 'on the cheap.'  Of course, there is money invested in the battery car.