The basis of this project is an American Flyer #429 body that I acquired from a friend of mine at a train show. The shell was missing the pilot assembly as well as some other parts. It wasn't a pristine example (it had some modifications in its past life) so it was a good candidate for this project.
The first step was to make the sideplates for the new windup motor. I laid out the basic outline and cut them from 16 gauge plain steel. I use 3/4" long brass standoffs with 6-32 threads as crossmembers. Mounting holes were drilled and tapped so it could be bolted to the existing motor mounts in the body. The axle holes were also drilled to make sure that the locomotive sat level from front to rear:
Once the basic motor had taken shape, it was time to test fit it in the body. The windup motor is actually just a touch wider than the original electric motor, so I had to carefully mill a little off the inside edges of the mounts. If someone ever wants to install an electric motor again, it could be done using a some small washers to take up the extra space. I did some test fitting with the motor in the shell before proceeding just in case major modifications were required:
Once I was satisfied that the motor and shell were going to fit together, it was time to get the motor running. Holes were drilled for the intermediate shafts, governor, and mainspring hubs. The parts were loaded into the motor for more test fitting as seen below:
At this point, I had proven that the motor would spin the axles. Even though this locomotive has six drivers, only the two end axles are driven, one from each mainspring. With a successful spin test under my belt, I soldered the drums for the governors in place on the left-had motor sideplate. I made up a couple of temporary clips to hold the outer ends of the mainsprings, pressed wheels on the axles. After cutting keyholes in the body, I finally got to see the locomotive move under spring power:
I used Marx 17 spoke die-cast drivers for the project - the design and size fit the locomotive surprising well. As you can see in the picture above, I machined the flanges off the center drivers so the loco could negotiate O27 curves without any problems. The test run revealed a couple of problems in the motor that were addressed, and it was time to start working on details.
The cylinders on the shell are open at the rear, and the original part that fit in there was missing. I made a new piece out of 18 gauge steel to fit, and bolted it to the original mounts on the shell. I used modified Marx windup siderods - they are simpler than the original AF rods and valve gear, but sufficient for a windup locomotive. A new pilot beam was machined out of a piece of bearing bronze that I had on hand, and a footboard was fabricated out of 18 gauge steel. Once a handrail was added to the pilot beam, the entire assembly was bolted in place. Some missing piping was made out of wire and put in place as well.
With all the details done, I painted the body and detail parts with satin black spray paint. The cab was numbered with 1/4" die-cut vinyl numbers, and a white paint pen used to highlight the edges of the running boards. An LED was installed in the headlight casting that will be powered by batteries someday - the battery holder I ordered is taking a while to get here. I paired the locomotive with a Marx tender - I was surprised how well they look together:
The finished locomotive runs well... with the big motor and die-cast shell, it weighs over 3 lbs, so it kind of lumbers around the layout. Running distance is basically the same as a stock Marx windup, but at a somewhat slower speed and with quite a bit more tractive effort. Here is the locomotive in action on my layout with some 7" Marx cars in tow:
